Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ2Comprehensive Characterization of Nano-Eu2O3 Reinforced Borotellurite Glasses: Synthesis, Physical, Structural, and Gamma and Neutron Attenuation Properties
Durmus, Hasan; Kilic, Gökhan; Ilik, E.; Kavaz, Erkan; Güler, Ömer; Birdoğan, Selcuk; Almisned, Ghada; Tekin, Hüseyin Ozan
This study presents a systematic investigation of lithium borotellurite glasses reinforced with nano-Eu2O3, with the aim to enhance the structural stability and radiation shielding performance. Glasses were synthesized with Eu2O3 concentrations from 0 to 10 mol % and characterized through density, X-ray diffraction, and transmission electron microscopy. The results showed that the density increased steadily from 4.030 to 4.734 g/cm3 with the Eu addition, while the molar volume also expanded, indicating that the incorporation of larger Eu3+ ions induced network expansion alongside densification. The X-ray diffraction patterns showed amorphous structures for all the compositions except Eu(n)2, which exhibited local crystallinity, later suppressed at higher Eu levels. The transmission electron microscopy pictures and energy dispersive spectroscopy mapping showed homogeneous nanoparticle distribution without clustering. Gamma-ray attenuation studies demonstrated clear improvements with Eu doping: the linear attenuation coefficient increased from 8.33 cm−1 (Eu(n)0) to 12.42 cm−1 (Eu(n)10) at 81 keV, while the half-value layer values decreased, confirming superior low-energy absorption. Experimental neutron studies revealed ΣR values comparable to standard neutron moderators, with Eu(n)10 showing a favorable balance of gamma and neutron shielding. Limitations include the restricted photon energy window and single neutron source. Future work should extend testing to higher energies, thermal/epithermal neutron ranges, and mechanical and durability assessments. Overall, nano-Eu2O3 reinforcement provides a promising pathway toward multifunctional transparent shielding glasses.
- MakaleAçık Erişim2026Scopus SJRQ1Investigation of the structural, thermal and radiation shielding properties of (Er0.2Yb0.2Sm0.2La0.2Eu0.2)2Zr2O7 high entropy oxide reinforced tin matrix composite
Güler, Ömer; Yılmaz, Demet; Kanca, M. Sait; Kök, Mediha; Güler, Seval Hale; Taşgın, Yahya
This study investigates the structural, thermal, and radiation shielding properties of (Er0.2Yb0.2Sm0.2La0.2Eu0.2)2Zr2O7 high entropy oxide (HEO) reinforced tin (Sn) matrix composites. In the first stage of the study, HEO powders were synthesized by grinding at 350 rpm for 30 h using a solid-state method with mechanical alloying assistance, and then calcining at 1100 °C for 8 h. In the second stage, composites were produced by mixing HEO-reinforced Sn matrix materials containing 1%, 5%, and 10% reinforcement, pelleting them under 200 MPa pressure, and then sintering them at 300 °C for 3 h. In the first stage of the study, (Er0.2Yb0.2Sm0.2La0.2Eu0.2)2Zr2O7 HEO powders were synthesized using a mechanical alloying-assisted solid-state route. In the second stage, HEO-reinforced Sn matrix composites containing 1 wt%, 5 wt%, and 10 wt% reinforcement were produced. The phase formation and crystallographic structure of the synthesized powders and composites were characterized using X-ray diffraction. Thermal behavior and phase stability were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The thermal analysis results revealed dehydration and structural stabilization processes at intermediate temperatures, while crystallization of the HEO phase was observed at elevated temperatures. In addition, oxidation behavior of the Sn matrix composites was evaluated, showing that the presence of HEO particles significantly suppresses mass gain during high-temperature oxidation, indicating improved thermal stability. Finally, the radiation shielding performance of the samples was experimentally evaluated within the photon energy range of 59.54–609.2 keV using Am-241, Ba-133, and Ra-226 radioactive sources together with a Ultra-Low Energy Germanium (ULEGe) detector. The results demonstrate that the incorporation of HEO particles leads to minor, energy-dependent variations in the radiation attenuation capability of the tin matrix, influenced by the presence of high atomic number rare-earth elements and modified microstructural characteristics. The gamma radiation protection coefficient (RPC) values indicate strong attenuation in the low photon energy region, decreasing to approximately 16–19% at 609.3 keV. Moreover, the measured neutron equivalent dose rates increase from 0.054 µSv/h for pure Sn to 0.285 µSv/h for the Sn–10%HEO composite, indicating that HEO incorporation modifies the neutron interaction behavior of the Sn matrix composites.
- MakaleYalnız künye2026Scopus SJRQ2Alloy-to-oxide transformation of a spinel-structured (Fe30Cr30Mn20Ni10V10)3O4 high-entropy alloy-oxide via mechanical alloying: Synthesis, phase stability, multivalent surface states, and radiation attenuation behaviour
Güler, Ömer; Güler, Seval Hale; Özkul, İskender; Baykal, Duygu Sen; Tekin, H.O.; ALMisned, Ghada
A spinel-structured high-entropy alloy-oxide (HEAO) with the nominal composition (Fe30Cr30Mn20Ni10V10)3O4 was synthesized via mechanical alloying followed by thermo-mechanical oxidation X-ray diffraction indicated the formation of a predominantly spinel-type cubic oxide phase after oxidation, with the observed reflections being consistent with the Fd-3m spinel structure, while SEM-EDS mapping showed a homogeneous cation distribution at the examined scale. XPS analysis revealed mixed valence states of Fe2+/Fe3+, Cr3+/Cr4+, Mn3+/Mn4+, Ni2+/Ni3+, and V4+/V5+. Thermodynamic parameters supported phase stability, with ΔSmix = 12.51 J K−1·mol−1 and Ω = 2.68. Gamma-ray attenuation properties were evaluated over 0.015-15 MeV. The linear attenuation coefficient decreased from 193.685 cm−1 at 0.015 MeV to 0.309 cm−1 at 1 MeV and stabilized near 0.137 cm−1 at 15 MeV. Correspondingly, the half value layer increased from 0.004 cm to 5.068 cm across the same energy range. The effective atomic number decreased from 24.58 at 0.015 MeV to approximately 15.37 at 1 MeV, followed by a moderate increase to 17.71 at 15 MeV. Comparative analysis with commercial stainless steel, titanium alloys, nickel-based superalloys, ferro-boron systems, and lightweight entropy alloys demonstrated that the synthesized HEAO exhibits intermediate yet stable attenuation performance, positioning it between low-density Al-based systems and high-density Ni-rich alloys. It can be concluded that the alloy-to-oxide strategy enables the production of a structurally stable spinel HEAO with consistent and competitive gamma-ray attenuation behaviour across a broad photon energy spectrum.
AtıfScopus1OpenAlex1
İncele - MakaleAçık Erişim2025Investigation of the Bioactivity Properties of TiZrCrNb0.3Ta0.07 Medium Entropy Alloy Produced from TNTZ Waste
Say, Yakup; Yayla, Nihal; Güler, Ömer; Güzel, Harun
High entropy alloys (HEAs) and medium entropy alloys (MEAs) have garnered significant attention as alternative materials in various fields due to their superior physical and chemical properties compared to conventional alloys. One of the most promising applications of this innovative material class is in biomaterials. In this study, a bio-medium entropy alloy (BioMEA), TiZrCrNb0.25Ta0.05, was successfully synthesized using non-toxic elements (Ti, Zr, Cr, Nb and Ta) through arc melting of TNTZ alloy waste. The produced BioMEA was comprehensively characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) to analyze its structural and chemical properties. Additionally, the in-vitro degradation, ion release, and bioactivity properties of the alloy were evaluated and compared with those of the conventional TNTZ alloy, with a focus on the effects of heat treatment. The results demonstrated that heat treatment did not cause significant changes in the microstructure of the TiZrCrNb0.25Ta0.05 alloy but led to the formation of intermetallic compounds such as Cr2Zr and Cr2Ta on the surface. Degradation tests revealed an unexpected mass gain across all sample groups after a four-week immersion period due to surface precipitation, surpassing the expected mass loss from degradation. Ion release analyses showed similar behavior between the TiZrCrNb0.25Ta0.05 and TNTZ alloys, with ion release levels in the ppb range, confirming that Ti was released at non-toxic levels. Bioactivity tests identified low lesvels of Ca-P-O deposition on all sample surfaces, with the highest bioactivity observed in the heat-treated TiZrCrNb0.25Ta0.05 sample. Overall, the findings suggest that the TiZrCrNb0.25Ta0.05 alloy has the potential to serve as an alternative biomaterial to the TNTZ alloy, with its bioactivity properties being further enhanced through heat treatment. Further studies are recommended to optimize its bioactivity and evaluate its in-vivo performance for biomedical applications.
- MakaleYalnız künye2025Scopus SJRQ2Tailoring ZrWNb-Based Refractory High Entropy Alloys: A Multidirectional Characterization Through Elemental, Physical, Thermodynamic, and Nuclear Radiation Attenuation Properties
Güler, Ömer; Özkul, İskender; Almisned, Ghada; Sen Baykal, Duygu; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.; Tekin, H.O.
This study explores the development and characterization of 18 novel ZrWNb[(X)(Y)] (where XY are Hf, Ta, Mo, V, Ti) refractory high entropy alloys (RHEAs) designed to enhance mechanical robustness, thermodynamic stability, and radiation shielding effectiveness. Through a rigorous analysis, we evaluated the elastic modulus, entropy, and enthalpy of mixing, atomic size difference, valence electron concentration, and the omega parameter to understand the alloys’ phase behavior and structural integrity. Our findings revealed a broad range of elastic modulus values, indicating diverse mechanical adaptability suitable for high-stress applications. The thermodynamic assessment highlighted several RHEAs with favorable phase stability, particularly ZrWNbTaHf and ZrWNbTiTaHf, which are poised for high-performance usage due to their balanced mixing entropy and enthalpy. This study also benchmarks the RHEAs against conventional alloys, with sample R1 exhibiting the lowest fast neutron effective removal cross section, underscoring its superior neutron shielding capabilities. Additionally, R1 demonstrated exceptional photon attenuation, as evidenced by its competitive half-value layer performance across an extensive energy spectrum. Collectively, these results position R1 as a standout candidate, offering a significant advancement in materials science for applications demanding stringent radiation shielding, such as in nuclear reactor environments and space exploration.
AtıfScopus4OpenAlex5İncele - MakaleAçık Erişim2025Scopus SJRQ2Dual-effect of Holmium(III) oxide and Boron Carbide reinforcement on physical, microstructural evolution and gamma-ray shielding performance of 316L-SS
Yayla, Nihal; Albayrak, M. Gökhan; Güler, Ömer; Almisned, Ghada; Sen Baykal, Duygu; Alkarrani, Hessa; Kilic, Gokhan; Tekin, Huseyin Ozan
This study provides one of the first comprehensive evaluations of 316L stainless steel composites reinforced with 10 wt.% B4C and varying concentrations of Ho2O3, proposing a new compositional design for simultaneous structural enhancement and dual gamma-neutron shielding optimization. XRD analysis confirmed the predominance of the austenitic phase with minor martensitic peaks at higher Ho2O3levels. SEM and EDX results revealed uniform dispersion and improved densification with increasing oxide content. The 316L-B4C-20%Ho2O3composite exhibited the highest mass attenuation coefficient (0.8953 cm2/g) and linear attenuation coefficient (6.73 cm−1) at 0.1 MeV, demonstrating superior gamma-ray shielding capability. The effective electron density increased from 2.86 × 1023to 5.82 × 1023electrons/cm³, while the energy absorption buildup factor (EABF) showed a consistent decrease with higher oxide concentrations. Although a slight reduction in fast neutron removal cross-section was observed, the composite maintained satisfactory neutron attenuation performance. Overall, the findings indicate that the 316L-B4C-20%Ho2O3system offers a promising balance between structural stability and dual radiation protection, making it a strong candidate for next-generation nuclear shielding materials.
AtıfScopus1İncele - MakaleAçık Erişim2025Scopus SJRQ1Enhanced radiation shielding via incorporating europium oxide in 316L stainless steel: Synthesis, physical, microstructural, shielding, and mechanical properties
Tekin, H.O.; Yayla, Nihal; Albayrak, M.Gökhan; Güler, Ömer; Baykal, Duygu Sen; Alkarrani, Hessa; ALMisned, Ghada
316L stainless steel is widely utilized in various industries due to its excellent corrosion resistance, mechanical strength, and biocompatibility, making it a preferred material for applications in nuclear filed. However, enhancing its radiation shielding and mechanical properties through reinforcement strategies, such as the addition of high-Z materials like Europium(III) oxide, is crucial for extending its functionality in high-radiation environments, where improved performance is essential for safety and durability. In this study, 316L stainless steel composites reinforced with varying amounts of Eu2O3 (1%, 5%, 10%, and 20%) were synthesized and investigated for their structural, mechanical, and radiation shielding properties. X-ray diffraction (XRD) analysis revealed that the face-centered cubic (FCC) structure of the steel matrix was preserved up to 5% Eu2O3 reinforcement, while higher concentrations led to phase formation and crystallographic changes. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis showed uniform element distribution at low reinforcement levels, with particle clustering at 20% Eu2O3. Transmission factors (TFs) were evaluated using PHITS simulations for photon energies of 0.662 MeV, 1.1732 MeV, and 1.3325 MeV. The 20% Eu2O3 composite exhibited the lowest TF and highest attenuation properties, confirmed by mass and linear attenuation coefficients. Elastic modulus values decreased from 224.46 GPa in pure 316L to 189.26 GPa with 20% Eu2O3 reinforcement, reflecting the inverse relationship between mechanical stiffness and radiation shielding performance. Benchmarking against other shielding materials demonstrated superior performance of the Eu2O3-reinforced steel in gamma-ray attenuation. The 20% Eu2O3 composite shows strong potential for applications in nuclear radiation shielding where attenuation efficiency is prioritized over mechanical properties.
AtıfScopus13OpenAlex14İncele - MakaleYalnız künye2025Scopus SJRQ1Impact of controlled oxidation and incorporation of high entropy rare-earth alloys (HE-REAs) on the structural, physical, optical, and radiation shielding performance of zinc-borate glasses
Ilik, E.; Guler, Seval Hale; Güler, Ömer; Durmus, Hasan; Kavaz, E.; Birdogan, Selcuk; ALMisned, Ghada; Kilic, G.; Tekin, H.O.
This study investigates the influence of high entropy oxide (HEO) and high entropy alloy oxide (HEAO) dopants on the structural, optical, and radiation shielding properties of zinc-borate glasses. Two synthesis routes were employed through direct mechanical alloying of five rare-earth oxides such as Sm2O3, Ho2O3, Er2O3, Yb2O3, Gd2O3 to form (SmHoErYbGd)2O3 HEO, and mechanical alloying of the corresponding rare-earth metals followed by oxidation to produce HEAO of the same elemental composition. The central hypothesis proposed that the dopant structure and oxygen coordination, not just elemental presence, critically influence the on characteristic behaviors in terms of radiation attenuation. Structural analyses confirmed that HEAO-doped glasses exhibit more homogeneous, amorphous networks. Optical characterizations revealed red-shifted absorption edges and lower Urbach energies in HEAO samples, indicating reduced disorder. HEAO-doped glasses showed superior gamma-ray shielding, with higher linear attenuation coefficients and lower half-value layers than HEO or undoped samples. Most notably, HEAO glass achieved the highest fast neutron removal cross-section, surpassing water, graphite, and B4C. These findings demonstrate that rare-earth high entropy alloy oxides offer a structurally optimized pathway for designing next-generation multifunctional glasses for radiation-related applications.
AtıfScopus9OpenAlex8İncele - MakaleYalnız künye2025Scopus SJRQ2Elastic modulus, nuclear radiation transmission properties of Fe-based/contained novel alloys for critical radiation applications
ALMisned, Ghada; Susoy, Gulfem; Baykal, Duygu Sen; Alkarrani, Hessa; Güler, Ömer; Issa, Shams A.M.; Zakaly, Hesham M.H.; Tekin, H.O.
This study explores the gamma-ray and neutron shielding properties and mechanical performance of eight Fe-based alloys with varying elemental compositions and densities. Different parameters such as mass attenuation coefficients, linear attenuation coefficients, half-value layer, tenth-value layer, mean free path, fast neutron removal cross-sections, transmission factors were analysed using PHITS and Phy-X/PSD codes. Moreover, elastic modulus values were calculated for each alloy sample. Our results reveal that the S9 alloy, with high density and tungsten contribution, exhibited superior shielding and mechanical properties, achieving the lowest TF, HVL, and TVL values. In contrast, the low-density S1 alloy performed weakest, reflecting its lighter elemental composition. Intermediate alloys like MAR-302 and Cupero-Nickel showed balanced performance, suitable for moderate shielding needs. Strong correlations between elemental compositions, particularly high-Z elements like tungsten and boron, and shielding efficiency were observed. It can be concluded that optimizing elemental composition and density is critical for designing alloys with enhanced multifunctional properties.
AtıfScopus3OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ2Effect of neodymium addition on the structural, mechanical, and magnetic properties of FeCoNiCu(MnCr)0.5 high entropy alloys
Yayla, Nihal; Şimşek, Telem; Boyrazlı, Mustafa; Güler, Ömer
Neodymium (Nd), a rare earth element, was incorporated into the [FeCoNiCu(MnCr)0.5] high-entropy alloy (HEA) at weight percentages of 0.5%, 1%, 2%, and 5%. The alloys were synthesized successfully using the arc melting method. X-ray diffraction (XRD) analysis confirmed that both the undoped and Nd-doped alloys exhibit a single-phase solid solution with a face-centered cubic (FCC) crystal structure, consistent with thermodynamic predictions derived from the Miedema model. Scanning electron microscopy (SEM) revealed a dendritic structure in the undoped alloy, which was replaced by Cu- and Cr-rich regions in the 5% Nd-doped alloy, as confirmed by energy dispersive spectroscopy (EDS). Differential scanning calorimetry (DSC) indicated an endothermic peak in the undoped alloy and minor thermal responses in Nd-doped samples, without distinct phase transitions within the 0–800 °C range. Mechanical testing demonstrated substantial enhancements in both hardness and tensile strength with increasing Nd content. The 5% Nd-doped alloy exhibited the highest performance, achieving a Vickers hardness of 370 HV and a tensile strength of 1186 MPa. Magnetic testing indicated ferromagnetic behavior in all samples, with Nd additions significantly enhancing magnetic properties. Notably, the 5% Nd-doped alloy achieved a saturation magnetization (Ms) of 41 emu/g and a coercivity (Hc) of 6.3 Oe, highlighting improved magnetic softness and rapid magnetization loss characteristic of soft magnetic materials.
AtıfScopus2WoS1OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ2Synthesis, microstructural refinement, and shielding optimization of Gd2O3-reinforced AISI 316L stainless steel: a multi-dimensional integration assessment for targeted protection applications
Yayla, Nihal; Albayrak, M Gökhan; Güler, Ömer; Sen Baykal, Duygu; Alkarrani, Hessa; ALMisned, Ghada; Issa, Bashar; Tekin, H.O.
This study investigates the multi-dimensional effects of increasing Gd2O3 reinforcement on the structural, mechanical, and gamma-ray shielding properties of AISI 316L stainless steel composites. Samples with varying Gd2O3 content (1%, 5%, 10%, and 20% by weight) were synthesized and characterized through x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) to assess the microstructural changes and homogeneity of Gd2O3 dispersion after mechanical milling. The addition of Gd2O3 significantly enhanced the gamma-ray shielding properties, with the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), and half-value layer (HVL) improving as the Gd2O3 content increased, particularly in low to moderate photon energy ranges. Simultaneously, the elastic modulus exhibited an inverse relationship, decreasing with higher Gd2O3 content due to the lower stiffness of gadolinium compared to iron. Transmission factor (TF) values also decreased, indicating enhanced photon attenuation with higher Gd2O3 content across various thicknesses. The experimental characterization confirmed improved Gd2O3 dispersion and material uniformity after mechanical milling, contributing to the composites’ superior radiation shielding performance. It can be concluded that Gd2O3-reinforced AISI 316L stainless steel composites offer a promising balance between enhanced radiation shielding properties and reduced mechanical stiffness, making them ideal candidates for applications requiring efficient and adaptable radiation protection especially for portable and non-structural shielding applications.
AtıfScopus3OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ1Blending effects of boron carbide and lanthanum(III) oxide reinforcements on the structural, physical, mechanical, and radiation shielding properties of 316L-stainless steel composites for nuclear applications
ALMisned, Ghada; Yayla, Nihal; Albayrak, M.Gökhan; Güler, Ömer; Baykal, Duygu Sen; Alkarrani, Hessa; Tekin, H.O.
Four composite samples were fabricated, maintaining 10 % B4C and varying La2O3 content from 0 % to 20 %. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDX) analyses confirmed the successful incorporation of reinforcements, preserving the austenitic structure of 316L-SS. Elastic modulus calculations revealed a gradual reduction from 225.0 GPa to 215.0 GPa with increasing La2O3 due to clustering and reduced homogeneity. Gamma-ray shielding properties demonstrated significant improvements, particularly at low and intermediate photon energies, with Sample 4 with 20 % La2O3 addition, achieving a 13.6 % higher linear attenuation coefficients (LAC) at 0.015 MeV. Neutron shielding highlighted Sample 4 as one of the most effective materials, outperforming conventional alloys. This study demonstrates the potential of 316L Stainless-Steel (316L-SS) + B4C + La2O3 composites as multifunctional materials for radiation-intensive applications, offering superior attenuation and structural stability. It can be concluded that optimization of reinforcement distribution would play an important role in balancing mechanical and shielding performance in next-generation nuclear materials.
AtıfScopus5OpenAlex5İncele - MakaleYalnız künye2025Scopus SJRQ2Comprehensive performance assessment of Bi- and Pb-based alloys for enhanced Gamma-Ray and neutron shielding applications
ALMisned, Ghada; Susoy, Gulfem; Baykal, Duygu Sen; Kilic, G.; Güler, Ömer; Tekin, H.O.
This comprehensive study investigates the radiation attenuation properties of various bismuth (Bi) and lead (Pb) based alloys, with a focus on identifying superior shielding materials for nuclear safety and industrial radiation protection. The research encompasses an in-depth analysis of seven alloys, namely GTSB5, Sn%40Bi, Bi50Sn50, A1, PbAl-4, Safe Alloy, and P1, assessing their efficacy in gamma-ray and neutron attenuation. Utilizing some computational tools, various parameters such as mass and linear attenuation coefficients, half and tenth value layer values, effective atomic and electron numbers, buildup factors, and transmission values were evaluated. Our findings highlight Alloy P1's outstanding performance, attributed to its high density (11.05 g/cm3) and optimized elemental composition, including Silver (Ag). In addition, P1 demonstrates exceptional gamma-ray attenuation across multiple energy spectra and superior neutron shielding capabilities, evidenced by its significant fast neutron removal cross-section (∑R, 0.12003 1/cm). The study revealed that the addition of Ag enhances the photon and beta particle absorption capacity, positioning P1 as a promising material in radiation shielding applications. The correlations between alloy density and gamma-ray shielding properties were particularly notable, with P1's density contributing to its enhanced attenuation capabilities. Furthermore, P1's lower half value layers (1.14469 cm) and tenth value layers (3.80256 cm) at 15 MeV indicate its efficiency in reducing radiation intensity with minimal material thickness.
AtıfScopus3OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ4Adsorption of RB-5 Dyestuff onto Boric Acid-Zinc Nanoalloys: Isotherm, Kinetic, and Thermodynamic Investigations
İlhan, Hasan; Güler, Ömer; Şi̇mşek, Tuncay; Alkan, Salih
In this study, boric acid-zinc (BA-Zn) nanoalloys were employed as an adsorbent for the removal of RB-5 dyestuff from aqueous solutions. The investigation focused on analyzing the impact of the initial dyestuff concentration, solution pH, temperature, and equilibrium contact time on the adsorption process of RB-5. The adsorption behavior of RB-5 onto the surface of BA-Zn-nanoalloys was explored, with a particular emphasis on the influence of initial dyestuff concentration and solution pH. The adsorption equilibrium data were subjected to analysis using Langmuir, Freundlich, DRK, and Temkin isotherm models. The results revealed a consistent alignment of RB-5 adsorption with both Langmuir and Temkin isotherms. Notably, the Langmuir adsorption capacity of BA-Zn-nanoparticles for RB-5 adsorption was determined to be 11.77mg / g at a temperature of 25°C. In the Temkin isotherm model, an adsorption constant (AT) of 1.003 was obtained. The calculated adsorption energy from the DR adsorption model was 1.09kJ / mol, implying a physical interaction-driven adsorption process. The empirical data further exhibited conformity with the pseudo-second order kinetic model, reflecting the rate-limiting step and overall kinetics of the adsorption process. Complementary to this, thermodynamic parameters such as enthalpy (ΔH0), Gibbs free energy (ΔG0), and entropy (ΔS0) were evaluated to discern the energetics of BA-Zn-nanoparticle RB-5 adsorption. This study not only underscores the effectiveness of BA-Zn nanoalloys as a potential adsorbent for RB-5 dyestuff removal but also contributes to the understanding of the underlying adsorption mechanisms and energetics. The insights gained hold implications for the development of sustainable and efficient strategies for wastewater treatment and environmental protection.
- MakaleAçık Erişim2025Scopus SJRQ2Designing multifunctional ferromagnetic high-entropy shape memory alloys (FHESMAs): Cr and Mn influence on structural, physical, magnetic and nuclear radiation shielding in NiFeGaCo alloys
Özkul, İskender; Karaduman, Oktay; Şimşek, Tuncay; Şimşek, Telem; Canbay, Canan Aksu; Güler, Ömer; ALMisned, Ghada; Tekin, H.O.
This study systematically investigates the influence of Cr and Mn additions on the structural, magnetic, and radiation shielding properties of NiFeGaCo-based ferromagnetic high-entropy shape memory alloys (FHESMAs) synthesized via the arc melting method. The fabricated NiFeGaCo, NiFeGaCoCr, and NiFeGaCoMn alloys were comprehensively characterized in terms of their phase formation, microstructure, martensitic transformation behavior, and magnetic performance. The results demonstrated that Mn addition significantly improved the magnetic properties, yielding the highest saturation magnetization (56.64 emu/g) and lowest coercivity (5.55 Oe), making NiFeGaCoMn highly suitable for soft magnetic applications. In contrast, Cr addition provided moderate magnetic behavior but enhanced structural stability with the largest crystallite size and lowest lattice strain. Moreover, gamma-ray and fast neutron shielding investigations revealed that the Cr-containing alloy exhibited superior performance in terms of linear attenuation coefficient, half-value layer, effective electron density, and fast neutron removal cross-section values, while Mn addition slightly reduced these shielding capabilities. It can be concluded that Cr addition offers a balanced advantage in designing FHESMAs with combined magnetic sensitivity and radiation shielding efficiency, whereas Mn addition is more effective for maximizing magnetic performance with a compromise in shielding characteristics.
AtıfScopus2OpenAlex2İncele - MakaleYalnız künye2025Scopus SJRQ2Phase Stability, Structural Properties, Electronegativity, Mechanical Properties, and Neutron and Gamma-Ray Attenuation Properties of Cantor High Entropy Alloys for Advanced Nuclear Applications
Tekin, H.O.; Güler, Ömer; Özkul, İskender; AlMisned, Ghada; Baykal, Duygu Sen; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.
High Entropy Alloys (HEAs) hold considerable potential for sophisticated nuclear applications, offering a vast spectrum of compositional tuning to enhance mechanical properties at high temperatures, as well as to increase resistance to radiation and corrosion. This study explores the suitability of Cantor HEAs, specifically the CoCrFeMnNi matrix enriched with elements such as Zr, Nb, Mo, Hf, Ta, and W, for nuclear applications. These elements were selected for their high atomic numbers and neutron capture cross-sections, vital for enhancing gamma-ray and neutron shielding properties. Utilizing advanced computational and theoretical methods, the elastic modulus of these alloys was theoretically estimated while their radiation attenuation capabilities were evaluated through different Monte Carlo simulation codes. CoCrFeMnNiW demonstrated the highest elastic modulus (340.9 GPa), indicating significant mechanical robustness. The addition of W resulted in superior gamma-ray attenuation, with the lowest gamma-ray transmission factors and highest neutron shielding effectiveness among the studied alloys. The calculated mass attenuation coefficients and effective removal cross-sections values demonstrate the potential of these HEAs to provide effective radiation shielding. Our results showed a clear correlation between the elastic modulus and radiation attenuation properties, suggesting that mechanical stiffness does not compromise shielding capabilities. The comprehensive analysis of thermodynamic and structural parameters, including entropy of mixing, mixing enthalpy, and Valence Electron Concentration (VEC), provided essential insights into phase stability and microstructural characteristics. It can be concluded that CoCrFeMnNiW and its related Cantor HEAs as promising materials for advancing nuclear technology, offering a new horizon for safer and more efficient nuclear systems.
AtıfScopus9OpenAlex13İncele - MakaleAçık Erişim2025Scopus SJRQ2Role of Rare-Earth Cerium in Martensitic Transformation and Magnetic Properties of Cu-Al-Mn Alloys
Özkul, İskender; Kalay, Ece; Karaduman, Oktay; Kizilgün, Yasİn; Güler, Ömer; Canbay, Canan Aksu
This study investigates the effects of different cerium additions on the properties of Cu-Al-Mn high-temperature shape memory alloy (HTSMA), such as the characteristic martensitic transformation temperatures, transformational kinetic parameters, and martensitic microstructures which are related to its shape memory mechanism and also to its magnetic behavior. Polycrystalline alloys with a base composition of Cu77.32Al21.02Mn1.67 (at.%) were synthesized, and varying concentrations of cerium (Ce-1 to Ce-4) were added for comparison. Differential scanning calorimetry tests revealed notable increments in transformation temperatures with cerium additions. Specifically, the austenite start temperature of the reference alloy increased from 143.75 °C to 194.88 °C by 0.05 at.% of Ce addition (Ce-3 alloy), corresponding to the formation of CeCu5 and Mn1.15Cu3.85Ce phases. However, excessive Ce addition in Ce-4 led to the over-stabilization of secondary phases, reducing the transformation temperatures. Microstructural analysis indicated that Ce addition of refined grains changed the crystallite size of the martensite structure and reduced lattice strain (from 0.72% to 0.34%). Magnetic characterization demonstrated that Ce addition shifted the alloy towards paramagnetic behavior, with M-H curves showing no significant coercive field or remanent magnetization across the studied alloy samples. These findings suggest that cerium can enhance the high-temperature performance of Cu-Al-Mn HTSMAs, with potential applications in environments requiring both shape memory and magnetic properties.
AtıfScopus3WoS3İncele - MakaleAçık Erişim2025Scopus SJRQ1High-Entropy Alloys and Oxides as Supercapacitor Electrodes: A Structural and Electrochemical Perspective for Energy Storage
Başgöz, Öyküm; Güngör, Ahmet; Güler, Ömer; Erdem, Emre
This study investigates the performance of high entropy alloys [Fe3Cr3Mn2NiV, HEA)] and high entropy oxides [(Fe3Cr3Mn2NiV)O4, HEO)] as electrode materials for supercapacitors. HEA is synthesized through mechanical alloying, followed by HEO forming via an oxidation process. XRD results demonstrate HEA comprises both amorphous and crystalline phases, whereas HEO has an entirely crystalline structure. SEM analyses showed HEA exhibits larger and irregular particles, whereas HEO displays a smaller and spherical morphology. EPR analyses revealed significant changes in defect structures and unpaired electron configurations during the transition from HEA to HEO. HEA is prone to diffusion-controlled processes due to their regular structure and strong magnetic interactions; however, HEO exhibits capacitive behavior based on surface redox reactions and pseudo-capacitive mechanisms due to their irregular structure and oxygen vacancies. CV analyses revealed that HEO contributes more capacitive via surface redox reactions, while GCPL results suggested that HEO demonstrated superior energy density (40.8 Wh kg−1) and power density (14.3 kW kg−1). Impedance analyses revealed that HEO exhibited reduced internal resistance and enhanced ion conductivity, whereas HEA demonstrated higher resistance and diffusion-controlled processes. In conclusion, HEA and HEO exhibit distinct energy storage mechanisms, and these materials can be optimized for supercapacitor applications.
AtıfScopus36WoS34OpenAlex18İncele - MakaleAçık Erişim2025Scopus SJRQ2An investigation on microstructural, physical, and radiation shielding properties Yb2O3 oxide dispersion-strengthened 316L-SS alloys
ALMisned, Ghada; Yayla, Nihal; Albayrak, M. Gökhan; Güler, Ömer; Sen Baykal, Duygu; Alkarrani, Hessa; Susoy, Gulfem; Tekin, H.O.
Oxide dispersion-strengthened alloys have emerged as a highly effective solution to address the physical, structural, and shielding challenges faced by traditional alloys in nuclear environments. This study presents a comprehensive evaluation of the microstructural, mechanical, and radiation shielding properties of Yb2O3 oxide dispersion-strengthened 316L stainless steel composites at varying Yb2O3 concentrations such as 1%, 5%, 10%, and 20% by weight. XRD analysis revealed lattice distortions, with crystallite sizes decreasing from 11.2267 nm to 9.3351 nm. SEM/EDX analyses confirmed homogeneous Yb2O3 dispersion at lower concentrations, with agglomeration at 20% Yb2O3. The mass attenuation coefficient increased from 56.103 cm2/g to 65.919 cm2/g at 0.015 MeV, marking a 17.5% enhancement. HVL decreased by 40.68% at 0.2 MeV for the 20% Yb2O3 sample. Additionally, the 20% Yb2O3 composite showed nearly 33% lower transmission factor at 3.0 cm thickness and 0.662 MeV. It can be concluded that Yb2O3 reinforcement significantly enhances the microstructural, and gamma-ray attenuation properties of 316L-SS composites, positioning them as promising materials for advanced nuclear shielding and structural applications.
AtıfScopus5OpenAlex5İncele - MakaleYalnız künye2025Scopus SJRQ2Comprehensive Computational Assessment of Al-Based High-Entropy Superalloys: Thermodynamic, Mechanical, and Radiation Shielding Characterization for Nuclear Applications
ALMisned, Ghada; Güler, Ömer; Özkul, İskender; Baykal, Duygu Sen; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.; Tekin, H.O.
This study investigates the radiation shielding properties of aluminum-based superalloy high-entropy alloys (HEAs) for potential use in advanced nuclear reactor applications. These HEAs, composed of five or more metals in equimolar or near-equimolar ratios, were evaluated for their thermodynamic stability, mechanical strength, and radiation attenuation capabilities. Key parameters such as entropy of mixing (ΔSmix), enthalpy of mixing (ΔHmix), valence electron concentration (VEC), and atomic size difference (δ) were analyzed. Radiation shielding properties, including mass attenuation coefficients (MAC), half-value layer (HVL), effective atomic number (Zeff), and exposure buildup factor (EBF), were assessed using various simulations. Alloy 12, with its superior MAC, lowest HVL, and high ΣR value, demonstrated exceptional effectiveness in gamma and neutron attenuation. These findings underscore the potential of aluminum-based HEAs, particularly Alloy 12, to enhance the operational capabilities and longevity of nuclear reactors, paving the way for the development of next-generation materials for high-radiation environments.
