Yazarlar
- Güler, Ömer(7)
- Tekin, H.O.(7)
- ALMisned, Ghada(6)
- Kavaz, E.(4)
- Güler, Seval Hale(3)
- Özkul, İskender(3)
- Albayrak, M. Gökhan(2)
- Baykal, Duygu Sen(2)
- Birdogan, Selcuk(2)
- Durmus, Hasan(2)
- Ilik, E.(2)
- Issa, Bashar(2)
- Kilic, G.(2)
- Yayla, Nihal(2)
- Albayrak, M Gökhan(1)
- Alkarrani, Hessa(1)
- Almisned, Ghada(1)
- Ates, Mehmet(1)
- Aydoğdu, Kumruya(1)
- Basgoz, Oykum(1)
- Bogatu, Coneliu(1)
- Canbay, Canan Aksu(1)
- Coşkun, Meltem(1)
- Kanca, M. Sait(1)
- Kar, Bulent(1)
- Karaduman, Oktay(1)
- Kök, Mediha(1)
- Qader, Ibrahim Nazem(1)
- Sen Baykal, Duygu(1)
- Öner, Ecem(1)
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ2Linking microstructural modifications of Ho2O3-doped borotellurite glasses to the enhancement of critical properties: Synthesis, structural, physical, and experimental Gamma-Ray and neutron transmissioncharacteristics
Kilic, G.; Ilik, E.; Kavaz, E.; Durmus, Hasan; Güler, Ömer; Birdogan, Selcuk; ALMisned, Ghada; Tekin, H.O.
This study investigates the effects of holmium oxide (Ho2O3) microparticle reinforcement on the structural, physical, and radiation shielding properties of borotellurite glasses with compositions ranging from 0 to 12 mol% Ho2O3. X-ray diffraction and TEM analyses confirmed the retention of amorphous structure across all samples, with localized short-range ordering observed at higher Ho contents. Glass density increased from 4.598 to 5.202 g/cm3 with increasing Ho2O3, while molar volume expanded from 27.94 to 30.61 cm3/mol, and oxygen packing density decreased from 0.605 to 0.551 g/cm3, indicating network expansion due to the substitution of lighter Li + ions by heavier Ho3+. Gamma-ray shielding properties significantly improved with Ho incorporation. At 81 keV, the linear attenuation coefficient increased from 8.33 to 13.70 cm−1, and the mass attenuation coefficient improved from 2.066 to 2.735 cm2/g. Moreover, effective atomic number rose from 44.9 to 52.5 and half-value layer decreased by 20.5% at 383 keV, and buildup factors dropped by up to 34% at 0.5 MeV. Neutron dose absorption improved, and the fast neutron removal cross-section increased from 0.1066 to 0.1113 cm−1. These results confirm that Ho2O3 contributes as a highly effective multifunctional dopant, significantly enhancing both gamma-ray and neutron shielding performance of borotellurite glasses, one of the most promising glass systems for advanced radiation protection applications.
AtıfScopus1OpenAlex1
İncele - 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.
AtıfScopus1OpenAlex1İncele - 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 - MakaleYalnız künye2025Scopus SJRQ1First exploration of Pr6O11 nanoparticle integration in borotellurite glasses: Synthesis, characterization, and performance for enhanced mechanical strength and radiation shielding
Kilic, G.; Ilik, E.; Kavaz, E.; Durmus, Hasan; Güler, Ömer; Birdogan, Selcuk; ALMisned, Ghada; Tekin, H.O.
This study investigates the incorporation of Pr6O11 nanoparticles into lithium borotellurite glass matrices to enhance their mechanical and radiation shielding properties. Glass compositions, synthesized with varying Pr6O11 concentrations from 0 to 8 mol%, exhibited increasing densities from 4.00783 g cm−3 to 4.94440 g cm−3 and reduced molar volumes, confirming nanoparticle-induced densification. X-ray diffraction analysis revealed amorphous structures with shifts in the hollow band indicating compact network rearrangements. Scanning electron microscopy and energy-dispersive X-ray analyses confirmed homogeneous Pr distribution up to 6 mol%, with clustering observed in 8 mol% samples. Vickers’ microhardness values progressively increased, highlighting enhanced mechanical strength due to reduced non-bridging oxygen ions and network cross-linking. Gamma-ray shielding experiments demonstrated superior performance of the 8 mol% sample (Pr8), with the highest mass attenuation coefficients, effective atomic number, and reduced half-value layer. Neutron attenuation assessments further confirmed improved shielding capabilities, with Pr8 achieving the highest effective removal cross-section. In conclusion, Pr6O11-doped lithium borotellurite glasses demonstrate significant potential for advanced radiation shielding applications.
AtıfScopus10OpenAlex11İncele - MakaleAçık Erişim2024Scopus SJRQ2Effects of Ga, Nb, V, Zr, and Cr on the crystal structures and thermal behavior of CuAlMn shape memory alloys
Özkul, İskender; Karaduman, Oktay; Canbay, Canan Aksu
CuAlMn alloys are cheaper and more promising alloy types compared to NiTi alloys. In this study, based on CuAlMn shape memory alloy, thermodynamic and structural characteristics of some new alloys containing four elements were investigated in detail. In this study, five new quaternary shape memory alloys, each containing a CuAlMn base alloy and a different fourth additive element (Ga, Nb, V, Zr, and Cr), were produced. The properties of the obtained alloys were characterized using a series of analysis methods such as X-ray diffraction (XRD), optical microscopy, differential scanning calorimetry (DSC), and differential thermal analysis (DTA). The results showed the effects of different elements on the crystal structures of the alloys and how different elements could change the thermal behavior of the alloys.
AtıfScopus4WoS3OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ1Fabrication and structural, physical, and nuclear radiation shielding properties for Oxide Dispersion-Strengthened (ODS) alloys through Erbium (III) oxide, Samarium (III) oxide, and Praseodymium (III) oxide into 316L matrix
Güler, Seval Hale; Güler, Ömer; Kavaz, E.; ALMisned, Ghada; Albayrak, M. Gökhan; Issa, Bashar; Tekin, H.O.
We report a comprehensive investigation on customization process of Oxide Dispersion-Strengthened alloys through Sm2O3, Pr2O3, and Er2O3 incorporation into 316L stainless steel matrix in terms of a desired enhancement in structural, physical, and nuclear radiation shielding properties. Oxide powders are incorporated into 316L stainless steel powder all with the same purity of 99.5%. These were Erbium oxide (Er2O3), Praseodymium oxide (Pr2O3), and Samarium oxide (Sm2O3). First, X-Ray diffraction and Scanning Electron Microscope/Energy-dispersive X-ray spectroscopy analyses are conducted in order to investigate their physical and structural properties. Next, two different experimental setups are employed using a133Ba and 241Am/Be sources for the measurements of gamma-ray and neutron transmission properties of Oxide Dispersion-Strengthened alloys. The maximum density increment is achieved through Er2O3 compared to other reinforced oxides. The detector counting value reached its minimum level when a 5% Er2O3 oxide dispersion was introduced into the 316L SS matrix. Similarly, the most significant degree of photon absorption, the highest values of mass attenuation coefficient, lowest half value layer, and most effective atomic number, were all attained by the same sample. Based on the findings derived from the investigation, it can be concluded that incorporating Er2O3 oxide into 316L steel can be considered as a viable option in terms of enhancing the critical properties of Oxide Dispersion-Strengthened alloys for extreme conditions such as nuclear reactors and other similar fields, where the behavioral attributes of the utilized materials are at utmost importance.
AtıfScopus22OpenAlex25İncele - MakaleAçık Erişim2024Scopus SJRQ2Innovative Al6061-gadolinium oxide ods alloys: fabrication and comprehensive characterization of microstructural, physical, mechanical, and radiation shielding properties
ALMisned, Ghada; Yayla, Nihal; Albayrak, M. Gökhan; Güler, Ömer; Baykal, Duygu Sen; Tekin, H.O.
This study explores the development and comprehensive characterization of Al6061-Gd₂O₃ composites, designed to enhance radiation shielding and mechanical properties for critical applications in environments exposed to ionizing radiation. The purpose of this research is to assess the effectiveness of Gd2O3 as a reinforcing material for Al6061, with the aim of creating a dual-function composite that combines structural integrity with superior gamma-ray and neutron attenuation capabilities. Using X-ray diffraction (XRD) and scanning electron microscopy (SEM), we analyzed the microstructural effects of varying Gd2O3 content, observing homogeneous dispersion at low concentrations and clustering at higher levels. Mechanical properties demonstrated that increased Gd2O3 content reduces the elastic modulus, indicating a trade-off between stiffness and shielding efficiency. Radiation shielding parameters, including Transmission Factor (TF), mass attenuation coefficient (MAC), and Fast Neutron Removal Cross Section (FNRCS), were evaluated through Phy-X/PSD and PHITS Monte Carlo simulations. Results indicate that Gd2O3 reinforcement significantly improves gamma-ray and neutron shielding, particularly at higher concentrations, making the composite viable for non-structural applications prioritizing radiation protection. The findings from this study highlight the potential of Gd2O3-reinforced Al6061 composites to serve as effective shielding materials in environments where radiation exposure is a primary concern.
AtıfScopus4OpenAlex5İncele - MakaleYalnız künye2023Scopus SJRQ1Oxides dispersion-strengthened (ODS) FeCoNiCuZn high entropy alloys through different rare earth elements: Synthesis, structural, physical, and experimental radiation transmission properties
Güler, Ömer; Kavaz, E.; Güler, Seval Hale; Almisned, Ghada; Özkul, İskender; Basgoz, Oykum; Tekin, H.O.
The oxide dispersoids within ODS alloys can act as sinks for radiation-induced defects, such as vacancies and dislocation loops, effectively reducing their mobility and preventing their accumulation. This property is crucial for HEAs employed in radiation-intensive environments, such as nuclear reactors. The objective of this research is to examine the impact of rare earth elements (REE) such as Y2O3, Er2O3, Pr2O3, and Sm2O3, on Oxides Dispersion-Strengthened (ODS) FeCoNiCuZn High Entropy Alloys (HEAs). The mechanical alloying technique is employed to produce a high entropy alloy consisting of Fe, Co, Ni, Cu, and Zn in their raw form. Subsequently, the raw alloy powder is enriched with separate amounts of Y2O3, Er2O3, Pr2O3, and Sm2O3. The microstructural analysis of the samples obtained from the mechanical alloying process was performed utilizing the X-ray diffraction (XRD) technique. In addition, scanning electron microscopy (SEM) was employed to analyze the ODS-HEA samples encoded S1, S2, S3, S4, and S5. To investigate the transmission properties of gamma-ray and neutron radiation, experimental studies are carried out using two types of detectors: Ultra High Purity Germanium (HPGe) detector and Canberra NP-100B BF3 gas proportional detector, respectively. The X-ray diffraction (XRD) spectra of samples did not display any observable peaks that could be attributed to the presence of dispersed rare earth element (REE) oxides. The uniform distribution of the metallic constituents that make up the High Entropy Alloy (HEA) is observed in the samples. Additionally, it can be observed that the implementation of the ODS-HEA technique, incorporating a 3% (wt.) Er2O3 additive, results in the most advantageous results with respect to the characteristics of gamma ray absorption. The S3 sample demonstrated the greatest degree of neutron absorption, as demonstrated by a recorded value of 0.857 μSv/h, where the S1 sample demonstrated the minimum level of absorption, as evidenced by a recorded value of 0.452 μSv/h. Based on the observed effects on neutron and gamma-ray attenuation behaviors in ODS-HEAs, it can be concluded that Er2O3 exhibits characteristics of a monotonic oxide. This feature is particularly advantageous for applications that necessitate a dual enhancement in these behaviors. It can also be concluded that the S1 sample may be deemed appropriate for situations where the utmost consistency of chain reactions in nuclear reactor fuel rods is desired, due to its possession of the lowest neutron absorption properties.
AtıfScopus22OpenAlex26İncele - MakaleAçık Erişim2021Scopus SJRQ2Effects of Aging on Magnetic and Thermal Characteristics of NiMnCoSn Magnetic Shape Memory Alloys
Kök, Mediha; Aydoğdu, Kumruya; Kanca, M. Sait; Qader, Ibrahim Nazem; Öner, Ecem; Coşkun, Meltem
Heusler shape memory alloys are important for many applications due to their typical magnetic and shape memory behaviors. In this study, a Ni50Mn36Sn12Co2 (at.%) alloy was manufactured by arc-melting technique, then the ingot cooled to ambient temperature in the natural atmosphere. Three different temperatures, including 500 °C (773 K), 700 °C (973 K), and 900 °C (1173 K), was selected for aging the samples cut from the main ingot. The impact of aging on the crystalline; microstructure; caloric; and magnetic properties of the alloys were investigated through x-ray diffraction (XRD); scanning electron microscope; differential scanning calorimetric (DSC), differential thermal analysis, and thermal gravimetric (TG); and physical property measuring system was investigated, respectively. The aging in different temperatures led to the shift DSC curve, such that the martensitic phase transformation temperatures of the sample aged at 773 K increased, however, the transformation at 973 and 1173 K decreased compared to the as-casted alloy. The different phase transformation behavior showed that the alloy aged at 773 K has the maximum elastic energy, enthalpy and entropy change compared to the reset of samples, on the other hand, its crystallite sized obtained from XRD analysis comparably diminished. Besides, the TG analysis revealed that the mass gain almost occurs at a temperature above 773 K, therefore the magnetization of the alloys aged at 973 and 1173 K decreased due to a thin oxide layer formed on the surface of the alloys.
AtıfScopus5WoS5OpenAlex7İncele - MakaleYalnız künye2019Scopus SJRQ4CHARACTERIZATION OF ERBIUM OXIDE NANOPARTICLES
Ates, Mehmet; Kar, Bulent; Bogatu, Coneliu
Considering the advantages of nanoscale materials such as being lighter, more robust, programmable materials, less material usage, less energy requirement during production phase, and no longer producing materials, it is important to produce nanomaterials and determine their properties. Therefore, the characterization of nanomaterials has become one of the pillars of material science. An important aspect of nanoscale material science is the method of characterization of materials that we use or study to learn more about them. In recent years, great importance has been given to rare earth materials with nanostructures. One of the rare earth elements is Erbium and it is one of the newly discovered materials that is used in high technology. Erbium oxide (Er2O3) nanoparticles (NPs) are used in electronic devices. It is used in capacitors, metal oxide semiconductor transistors, and as dopants for optical fiber and laser materials. In this study, Erbium based Er2O3 NPs were characterized. The characterization of Er2O3 was realized using X-ray diffraction (XRD), scanning electron microscopy (SEM), the energy dispersive X-ray (EDX), and Fourier transform infrared spectroscopy (FT-IR). The number of specific peaks and their position fit very well with those from standard XRD spectrum and revealed pure Er2O3 nano oxide. SEM analysis of these particles showed their spherical shapes that are in great extent uniform distributed with nano sizes ranged between 40-60 nm.