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Öğe A comprehensive study of cytosine-ZnO interactions: Theoretical and experimental insights(Elsevier, 2025) Bulut, Niyazi; Keser, Serhat; Zanchet, Alexandre; Zuchowski, Piotr S.; Ates, Tankut; Kilic, Irfan; Kaygili, OmerThis paper presents a comprehensive investigation of the adsorption of cytosine, a DNA base, on ZnO model clusters, specifically Zn2O2, Zn3O3, Zn4O4, Zn6O6, Zn8O8 ring (R) and cubic rocksalt. A density functional theory (DFT) method was used to simulate the adsorption of cytosine on ZnO (C/ZnO) clusters. The B3LYP/LanL2DZ method, which includes a correction for the dispersion contribution, was used. The calculated energy gap (Eg) for cytosine showed a strong dependence on the cluster size, highlighting variations corresponding to the dimensions of the clusters. The proposed physisorption mechanism involves the formation of an N...Zn bond between cytosine and the active Zn site on ZnO. In addition, experimental data, including microscopic and spectroscopic evidence, were integrated to further elucidate the interactions between cytosine and ZnO. A composite of C and ZnO was prepared by the wet chemical method and characterised by SEM, XRD and FT-IR analyses. The interaction of cytosine with ZnO nanoparticles was observed by UV-vis spectroscopy. The experimental results were then compared with those obtained from DFT calculations, taking into account the new insights into the cytosine-ZnO interactions. This comparison provided a holistic understanding of the system.Öğe Advances in metallic ion-doped hydroxyapatite: unlocking enhanced structural, biological, and functional properties for cutting-edge biomedical applications(Springer, 2026) Kareem, Rebaz Obaid; Barzinjy, Azeez A.; Ates, Tankut; Bulut, Niyazi; Keser, Serhat; Kaygili, OmerHydroxyapatite (HAp) is a biomaterial that has been extensively studied for its exceptional biocompatibility, osteoconductivity and non-toxic nature, making it highly suitable for applications in bone and dental tissue engineering. This review evaluates the incorporation of metallic ions into the HAp lattice as a strategic approach to optimize its structural integrity, mechanical performance and biological functionality. Quantitative findings from recent studies show that Ag+ doping at 1 wt% reduces bacterial growth by over 95%, but higher doses ( > 3 wt%) can reduce cell viability by up to 20%. Sr2 + (5 wt%) improves bone regeneration by 25%, though excessive levels may alter lattice stability. Zn2 + at 3 wt% enhances osteoblast proliferation by 60% but can slightly reduce thermal stability. Cu2 + improves angiogenesis and antimicrobial efficacy, but high concentrations can induce cytotoxicity. Furthermore, metallic ion doping enhances the dielectric properties and contributes to anti-cancer capabilities, expanding HAp's therapeutic potential. The review also highlights advanced applications of metallic ion-doped HAp, including its role in drug delivery systems, implant surface coatings, and even environmental remediation. By synthesizing findings from recent studies, this comprehensive analysis underscores the transformative impact of metallic doping in optimizing HAp for diverse biomedical applications. These advances represent an important step in the development of multifunctional biomaterials, paving the way for innovative solutions to medical and environmental challenges.Öğe Analysing the impact of Dy dopants on Zn-based hydroxyapatites: modelling and characterization perspectives(Indian Acad Sciences, 2024) Buyuk, Oznur; Bulut, Niyazi; Temuz, M. mursit; Orek, Cahit; Ates, Tankut; Kaygili, Omer; Kurucay, AliThis study is aimed to investigate the effects of introducing dysprosium (Dy) into Zn-based hydroxyapatite (HAp) at various concentrations (0.45, 0.90, 1.35 and 1.80%). The structural and optical properties of pure and doped HAp were thoroughly examined through theoretical and empirical analyses, including X-ray diffraction, Raman spectroscopy and Fourier transform infrared (FTIR) studies. The results confirmed the successful incorporation of Dy into the HAp lattice without significantly affecting its thermal stability or stoichiometry. The introduction of Dy into Zn-based HAp led to notable alterations in several material parameters. The lattice parameters, crystallinity, lattice stress, strain and anisotropic energy density varied with different Dy concentrations. In comparison with undoped HAp, all Dy-doped Zn-based HAps exhibited reduced crystallite size values, indicating a change in the microstructure. Furthermore, the material density increased from 3.159 to 3.228 g cm-3 with Dy doping. The band gap (BG), an important parameter for optical applications, is consistently decreased from 4.6 to 3.9 eV as the Dy concentration increased. This decrease in BG suggests the potential for improved photocatalytic or optoelectronic properties in Dy-doped Zn-based HAp. Additionally, the linear absorption coefficient (LAC) increased, indicating enhanced light absorption. Overall, this study provides a comprehensive understanding of structural and optical modifications induced by Dy doping in Zn-based HAp. These findings contribute to the potential application of Dy-doped Zn-based HAp in various fields, including biomedicine, photocatalysis and optoelectronics.Öğe Comprehensive analysis of the impact of iron and terbium co-dopant levels on the structural, thermal, and spectroscopic properties of hydroxyapatite(Elsevier Sci Ltd, 2025) Kaygili, Omer; Duskun, Yusuf; Barzinjy, Azeez A.; Kareem, Rebaz Obaid; Ates, Tankut; Keser, Serhat; Ince, TuranIn recent years, there has been a growing interest in biomaterials for improving human living conditions. Hydroxyapatite (HAp), a biomaterial widely used in bone and teeth restoration, has been doped with iron (Fe) and terbium (Tb) to enhance its electronic properties and potential biomedical applications. Theoretical calculations revealed a decreasing trend in bandgap values with increasing concentrations of Fe and Tb, suggesting a shift from insulating to semiconducting behavior. The synthesized Fe and Tb doped HAp samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The results showed that the addition of Fe and Tb dopants led to changes in the lattice parameters, crystallinity, and morphology of HAp structure. The doped HAp samples exhibited improved thermal stability, and their FTIR and Raman spectra confirmed the presence of the phosphate group. SEM analysis revealed sphere-like nanoparticles and EDX results confirmed the presence of Fe and Tb in the doped samples. The (Ca + Tb + Fe)/P molar ratios were close to the ideal value of 1.667. The study demonstrates the potential of Fe and Tb-doped HAp as multifunctional materials in biomedicine and other fields requiring tunable electrical properties.Öğe Comprehensive investigation of the electronic properties of zinc and cobalt doped hydroxyapatite(Springer, 2024) Tekin, Yusuf Samil; Ates, TankutThis study presents a comprehensive investigation into the electronic properties of Hydroxyapatite (HAp) doped with Zinc (Zn) and Cobalt (Co). Five distinct compositions, denoted as 0.15Zn-HAp, 0.15Co-0.15Zn-HAp, 0.30Co-0.15Zn-HAp, 0.45Co-0.15Zn-HAp, and 0.6Co-0.15Zn-HAp (at%,) have been systematically studied employing Density of States (DOS) and band structure calculations. The computed band gap values for these compositions were determined to be 4.6663, 4.6888, 4.7049, 4.7159, and 4.7082 eV, respectively. These results illuminate the profound influence of Zn and Co doping on the electronic structure of Hydroxyapatite. These findings hold significant implications for the potential applications of these materials in diverse technological and biomedical domains. The systematic approach and precise electronic property characterizations presented in this study provide a robust foundation for further advancements in the realm of advanced materials, with particular relevance to the development of innovative materials for use in cutting-edge technologies and medical applications.Öğe Comprehensive structural characterization of chromium-doped zinc oxides(Springer-Verlag Italia Srl, 2025) Ates, Tankut; Keser, Serhat; Bulut, Niyazi; Kaygili, OmerThis study presents a comprehensive investigation of the effects of chromium (Cr) on the structural properties of zinc oxide (ZnO). X-ray diffraction (XRD) analysis confirmed the formation of the ZnO wurtzite phase for all samples. At lower Cr concentrations (up to 1.4 at%), Cr3(+) ions were successfully incorporated into the ZnO lattice without forming secondary phases, indicating effective substitutional doping. However, at higher Cr contents (>= 2.8 at%), the formation of a secondary ZnCr2O4 spinel phase was observed, suggesting that the Cr solubility limit in ZnO was exceeded. Cr content influenced various crystal-structure-related parameters such as crystallinity, crystallite size, lattice parameters, Zn-O bond length, lattice strain, and stress. The texture coefficient (TC(hkl)) analyses revealed a shift in preferential growth orientation from the (200) plane to the (004) plane with increasing Cr concentration. FTIR spectra supported the presence of Zn-O vibrational modes and changes in surface chemistry, while SEM images showed morphology evolution and increased surface complexity with doping.Öğe Effects of gadolinium-doping on the structural, thermal, and spectroscopic properties of zinc-based hydroxyapatites(Elsevier Sci Ltd, 2026) Ates, Tankut; Cretin, Burhan Tarik; Goldberg, Margarita A.; Allame, Sara Sabah Khaeoon; Donskaya, Nadezhda O.; Fomin, Alexander S.; Kaygili, OmerThis study examines how increasing gadolinium (Gd) content influences the structural, electronic, thermal, and biological properties of zinc-based hydroxyapatite (HAp) synthesized by a wet chemical method and supported by DFT modeling. Co-doping with Gd alters the HAp/beta-TCP phase ratio, induces detectable changes in lattice parameters, crystallite size, and microstrain, and is in excellent agreement with theoretical predictions. DFT calculations show a systematic bandgap reduction from 4.5154 to 4.3136 eV with rising Gd concentration, demonstrating that rare-earth incorporation effectively tunes the electronic structure of HAp. FTIR and Raman analyses confirm the preservation of characteristic phosphate and hydroxyl vibrational modes, while thermal analysis indicates high stability up to 900 degrees C. SEM/EDX results show morphology and composition shifts with dopant level. Cell viability tests reveal strong biocompatibility for all samples except the highest Gd-doped formulation. Overall, Zn-Gd co-doping provides a robust strategy for engineering multifunctional bioceramics.Öğe Effects of gallic acid and quercetin on the structural, thermal, spectroscopic, in vitro biocompatibility and electronic properties of Au-based hydroxyapatite structure(Elsevier Science Sa, 2024) Keser, Serhat; Dogan, Ahmet; Ates, Tankut; Barzinjy, Azeez A.; Ates, Burhan; Tekin, Suat; Kaygili, OmerThe aim of this study is investigating the structural, thermal, spectroscopic, electronic and biocompatibility properties of the Au-based hydroxyapatites containing quercetin (Q) or gallic acid (GA) at various concentration. Different characterization techniques including; XRD analysis, FTIR and Raman spectroscopies, differential thermal analysis, SEM and EDX analysis were utilized. Cell cytotoxicity test was conducted with the cells of MG63 human bone cancer, hFOB 1.19 human osteoblast and Caco-2 human colon cancer. It has been shown that the utilized samples had no cytotoxic activity on the L-929, hFOB 1.19 and MG-63 cells. However, these samples had cytotoxic activity on Caco-2. The current study showed that the bandgap of the un-doped HAp structure was 4.976 eV. The crystallite size is also affected by Au-doping, type of the as-used biological additive and its amount. Also, the as-produced samples were thermally stable in the range from room temperature to 1000 degrees C. The particle size distributions of the samples were found at variable ranges. The molar ratios were close to the stoichiometric value of 1.667. These novel findings not only expand our appreciation for the role of dopants in materials science but also opens avenues for deliberate engineering of electronic properties for enhanced performance in various applications.Öğe Effects of Yttrium Doping on Erbium-Based Hydroxyapatites: Theoretical and Experimental Study(Mdpi, 2022) Ahmed, Lana Omar; Bulut, Niyazi; Kebiroglu, Hanifi; Alkhedher, Mohammad; Ates, Tankut; Koytepe, Suleyman; El Din, ElSayed M. TagThis is the first investigation of yttrium (Y) and erbium (Er) co-doped hydroxyapatite (HAp) structures, conducted using theoretical and experimental procedures. By using a wet chemical method, the materials were synthesized by varying the concentration of Y amounts of 0.13, 0.26, 0.39, 0.52, 0.65, and 0.78 at.% every virtual 10 atoms of calcium, whereas Er was kept fixed at 0.39 at.%. Spectroscopic, thermal, and in vitro biocompatibility testing were performed on the generated samples. Theoretical calculations were carried out to compute the energy bandgap, density of states, and linear absorption coefficient. The effects of Y concentration on thermal, morphological, and structural parameters were investigated in detail. Raman and Infrared (FTIR) spectroscopies confirmed the formation of the HAp structure in the samples. Theoretical investigations indicated that the increasing amount of Y increased the density from 3.1724 g cm(-3) to 3.1824 g cm(-3) and decreased the bandgap energy from 4.196 eV to 4.156 eV, except for the sample containing 0.39 at. % of the dopant, which exhibited a decrease in the bandgap. The values of linear absorption appeared reduced with an increase in photon energy. The samples exhibited cell viability higher than 110%, which revealed excellent biocompatibility for biological applications of the prepared samples.Öğe Experimental and theoretical analysis of bismuth Co-doped erbium-based hydroxyapatites(Springer, 2025) Ali, Aenas Laith; Mahmood, Bahroz Kareem; Kareem, Rebaz Obaid; Ates, Tankut; Barzinjy, Azeez A.; Bulut, Niyazi; Kaygili, OmerThis study explores the impact of bismuth (Bi) and erbium (Er) co-doping on the structural, morphological, and electronic properties of hydroxyapatites (HAp). Bi/Er co-doped HAp samples at varying concentrations were synthesized through a wet chemical process and characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Additionally, density functional theory (DFT) was employed to analyze band structure (BS), energy gap (Eg), density of states (DOS), and linear attenuation coefficient (LAC). Results revealed a systematic decrease in the energy gap from 4.0340 eV to 3.9222 eV with increasing Bi content, highlighting a reduced band gap energy trend as the Bi and Er concentrations increase. Higher Bi concentration also influenced the DOS and BS, and reduced crystallite size (D) across samples. Among them, the 0.26Bi-0.39Er-HAp sample exhibited the lowest crystallinity (76.56%) and smallest crystallite size (27.84 nm). This study provides valuable insights into how co-doping affects HAp properties, with potential implications for biomedical and environmental applications.Öğe Experimental and theoretical characterization of Bi-based hydroxyapatites doped with Ce(Elsevier Sci Ltd, 2022) Kareem, Rebaz Obaid; Kaygili, Omer; Ates, Tankut; Bulut, Niyazi; Koytepe, Suleyman; Kurucay, Ali; Ercan, IsmailThis study deals with the theoretical and experimental characterizations of Bi-based hydroxyapatites (HAps) codoped with Ce. Five samples of Bi-based HAp (at a constant amount of 0.125 at.%) with additions of the Ce in various amounts (0, 0.125, 0.25, 0.375, and 0.500 at. %) were synthesized by using the wet chemical method. The prepared samples were investigated experimentally by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, differential thermal analysis (DTA), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). All the samples were also modeled by using a density functional theory (DFT), and theoretical results were obtained. Both experimental and theoretical results showed that the lattice parameters and unit cell volume were significantly affected by Ce content. Calculated bandgap energy results of the samples gradually reduced from 4.6308 eV to 4.5299 eV. The bandgap decreased with increasing Ce content, and the densities of states (DOS) values were also affected by the amount of Ce. It was found that the sample doped with 0.500 at. % Ce showed the best biocompatibility among all the as-synthesized samples. The linear absorption coefficient increased with increasing amounts of Ce in all samples, while this parameter decreased with increasing photon energy. The density increases with the increasing Ce content ranging from 3.1615 g cm-3 to 3.1772 g cm- 3. Both crystallite size and crystallinity decreased gradually with the increasing amount of Ce. FTIR and Raman spectra confirm the formation of the HAp structure for all the samples.Öğe Experimental and theoretical characterization of Dy-doped hydroxyapatites(Springer, 2023) Isen, Fatih; Kaygili, Omer; Bulut, Niyazi; Ates, Tankut; Osmanlioglu, Fatih; Keser, Serhat; Kareem, Rebaz ObaidThe effects of adding Dy to the hydroxyapatite (HAp) structure were investigated experimentally and theoretically. The as-obtained experimental results with an increasing amount of Dy are as follows. X-ray diffraction, Raman, and Fourier transform infrared measurements verified the HAp structure for each specimen. The crystallinity, lattice parameters, lattice stress, strain, and anisotropic energy density were affected. Thermal stability and stoichiometry were not affected. It was observed that all the Dy-doped HAps have smaller crystallite size values compared to the un-doped HAp. The cell viability obtained from mouse fibroblast cell (L929) was higher than 82%, indicating all the samples were biocompatible. The theoretical findings, obtained from the density functional theory (DFT) calculations, exhibited a continuous decrease in the bandgap from 4.7109 to 3.7982 eV, an increase in the density from 3,155 to 3,189 kg m(-3), and an increase in the linear absorption coefficient.Öğe Experimental characterization and theoretical investigation of Ce/Yb co-doped hydroxyapatites(Elsevier Science Sa, 2022) Acar, Serdar; Kaygili, Omer; Ates, Tankut; Dorozhkin, Sergey, V; Bulut, Niyazi; Ates, Burhan; Hssain, Ala HamdIn the present study, the effects of variable amounts of Yb addition on the structural, thermal, and in vitro biocompatibility properties of Ce-doped hydroxyapatite (HAp) samples synthesized via the wet chemical method were investigated. Besides, the prepared formulations were also modeled for making the theoretical investigations. The single-phase compositions were detected for all samples, and no formation of additional phases was observed. Doping with Yb was observed to produce some variations in the lattice parameters, unit cell volume, lattice strain, and lattice stress. While a decreasing trend in the crystallite size and crystallization percent with increasing Yb content was found, a gradual increase in the anisotropic energy density was observed. All samples were found to be thermally stable from room temperature to 1000 degrees C with negligible mass losses during heating. No significant morphological changes were caused by the addition of Yb. For all samples, the numerical values of (Ca + Ce + Yb)/P molar ratio were found to be close to that for stoichiometric HAp (1.67). It was observed that the increased Yb additive caused a decrease in cell viability values. A continuous decrease in the bandgap energy with the increasing amounts of Yb added to the Ce-based HAp structure was observed from the theoretical investigations. A sharp decrease in the cell viability of the Ce-based HAp was observed with the addition of Yb.Öğe Exploring the electronic band structure, spectroscopic signatures, and structural properties of Er3+-based hydroxyapatites co-doped with Ce3+ions(Elsevier, 2023) Ahmed, Lana Omar; Bulut, Niyazi; Banares, Luis; Kaygili, Omer; Kebiroglu, Hanifi; Ates, Tankut; Ates, BurhanIn this work, we have investigated Ce3+ and Er3+ co-doped hydroxyapatite (HAp) structures both theoretically and experimentally for the first time. The Ce3+ content was incrementally varied in steps of 0.13 at. %, ranging from 0.13 at. % to 0.78 at. %. Meanwhile, the Er3+ content remained constant at 0.39 at. % for all samples. We employed X-ray diffraction, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential thermal analysis, differential scanning calorimetry, and in vitro biocompatibility tests to examine the prepared samples. Our findings demonstrate that the thermal behavior, morphology, and other crystal structure-related parameters are significantly influenced by the con-centration of Ce3+. The formation of HAp structures was confirmed through FTIR and Raman spectroscopic analyses. Furthermore, we conducted theoretical calculations to determine the linear absorption coefficient, density of states, and bandgap. These calculations revealed that the addition of Ce3+ atoms at varying concen-trations resulted in an increase in density from 3.174 to 3.195 g cm-3, while the bandgap gradually decreased from 4.16 to 4.10 eV, except for the 0.26Ce-0.39Er-HAp and 0.52Ce-0.39Er-HAp compositions, where the energy bandgap exhibited an increase.Öğe Impact of pyrocatechol on the structural, spectroscopic, thermal characteristics, and in vitro bioactivity of gadolinium-enhanced hydroxyapatites(Elsevier, 2025) Keser, Serhat; Demirbilek, Fatos; Barzinjy, Azeez A.; Kareem, Rebaz Obaid; Mahmood, Bahroz Kareem; Ates, Tankut; Kaygili, OmerIn this study, the effects of pyrocatechol content on the structural, thermal, spectroscopic, and biocompatibility properties of gadolinium (Gd) based hydroxyapatites (HAs) were investigated using X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis, thermogravimetric analysis, and scanning electron microscopy. The results, of this study, show that the energy bandgap (Egap) of Gd-doped HAs decreases to 4.1978 eV, indicating a narrowing of the electronic energy levels compared to pure HAs. The doping of Gd3+ further enhances these effects, as confirmed by enhanced photoluminescence intensity attributed to cooperative energy transfer mechanisms between the dopants. The two most biocompatible materials in the HAs series were determined as 0.42Gd-HA (94%) and P16-0.42Gd-HA (91%). These results demonstrate that even small concentrations of dopant like Gd can meaningfully impact the material's electronic and optical properties, offering potential for its application in areas where a higher bandgap and insulating properties are essential, such as in biomedical implants, coatings, or electronic insulators.Öğe Impact of quercetin and gallic acid on the electronic, structural, spectroscopic, thermal properties and in vitro bioactivity of silver-modified hydroxyapatite(Elsevier Science Sa, 2025) Keser, Serhat; Firat, Melikehatun; Barzinjy, Azeez A.; Kareem, Rebaz Obaid; Ates, Tankut; Ates, Burhan; Kaygili, OmerHydroxyapatite (HAp) possesses outstanding characteristics, for instance biocompatibility and osteoconductivity, which are vital for bone reconstruction. Nevertheless, it remains passive against infectious bacteria that can cultivate in compromised bone tissue, and its usage in some individuals under care might result in some objectionable provocative responses. Gallic acid (GA) and quercetin (Que) are recognised for their explicit biological activites. Connecting these properties with silver-modified HAp is remarkably interesting. The current study examined the preparation of un-doped HAp and Ag-based samples in the presence of various extents of GA and Que using the neutralization method at room temperature. The impact of GA and Que on the electronic, structural, thermal, spectroscopic, and biocompatibility properties of HAp and Ag-modified HAp were investigated intensively. Also, mouse fibroblast (L929), human osteoblast (hFOB 1.19), human bone cancer (MG-63) and human colon cancer (Caco-2) cell lines obtained from the ATCC were used for cytotoxic and biocompatibility assays. The bandgap of the distinct regions (occupation of Ca(I) and Ca(II) sites) using DFT were 3.837 and 4.211 eV, respectively. This study showed that introducing Ag as a dopant reduced the bandgap dramatically. X-ray diffraction analysis revealed that the as-prepared samples possess polycrystalline structure. While, the lattice parameters and volume of the unit cell were increased after adding Ag as a dopant. However, both GA and Que containing samples, remarkably decrease these parameters. Both FTIR and Raman spectroscopy utilized to investigate the nature of bonding structure for the utilized samples. It has been shown that the addition of Ag into the HAp causes an increase in the specific heat capacity. SEM images and EDX analysis confirm the distribution of the utilized elements and the purity of the samples. Overall, the prepared Ag-HAp/GA and Ag-HAp/Que samples offered structural and chemical characteristics close to those of ordinary bone that make them a good candidate for bone tissue regeneration.Öğe Investigation of structural, spectroscopic, dielectric, magnetic, and in vitro biocompatibility properties of Sr/Ni co-doped hydroxyapatites(Elsevier Sci Ltd, 2022) Ercan, Filiz; Kayed, Tarek S.; Kaygili, Omer; Bulut, Niyazi; Almohazey, Dana; Ates, Tankut; Ercan, IsmailIn this study, the changes caused by Ni and Sr additives on the structural, thermal, dielectric, and magnetic properties of hydroxyapatite (HAp) samples were examined and reported for the first time in detail. Some effects of the Sr/Ni site disorder on the crystallographic, dielectric, and magnetic properties in Sr/Ni-HAp have been examined, as well as their cytotoxicity effects. The addition of Ni affected the morphology of nanoparticles with a low agglomeration increase. Our results showed that the dielectric constant (epsilon') and dielectric loss (epsilon '') have greater values at low frequencies than at higher frequencies for all the samples. It can be concluded that Ni and Sr additions to the HAp structure contribute to the development of thermal, magnetic, and dielectric properties required to mimic natural HAp in the study conducted with the idea of creating a medical application area for bone healing and regeneration. The cytotoxicity test of the produced nanoparticles and the evaluation of the results were also performed using human foreskin fibroblasts (HFF). The viability of cells after treatment for 48 h ranged between 50 and 75%. While 0.37Ni-0.37Sr-HAp and 1.11Ni-0.37Sr-HAp were similar to 0.37Sr-HAp, 0.74Ni-0.37Sr-HAp had the highest cellular viability. At 0.1 mg/mL, 0.74Ni-0.37Sr-HAp had a viability of 79.97% compared to the untreated control cells. Our Sr/Ni-HAp nanoparticles have promising medical applications in bone healing and regeneration.Öğe Investigation of the Structural, Thermal, Spectroscopic, and Electronic Properties of Praseodymium-based Hydroxyapatites Co-doped with Silver and Zinc in Varying Concentrations(Budapest Univ Technology Economics, 2025) Kareem, Rebaz Obaid; Ates, Tankut; Barzinjy, Azeez A.; Temuz, Mehmet Mursit; Ince, Turan; Bulut, Niyazi; Kaygili, OmerThis study investigates the crystal structure, energy gap, band structure, spectroscopy, thermal, and electrical properties of Pr3+-based hydroxyapatites (HAp) co-doped with Zn2+ and Ag+ in varying concentrations. The synthesized samples, designated as 0.25Zn-0.25PrHAp, 0.50Zn-0.25Pr-HAp, 0.75Zn-0.25Pr-HAp, 0.25Ag-0.25Pr-HAp, 0.50Ag-0.25Pr-HAp, and 0.75Ag-0.25Pr-HAp, were prepared using a wet chemical method. The materials were characterized by Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential thermal analysis (DTA), and thermogravimetric analysis (TGA). Additionally, theoretical calculations employing density functional theory (DFT) were conducted to analyze the band structure (BS), energy gap (Eg; EHOM & oacute;ELUMO), and density of states (DOS). Results revealed a progressive reduction in the bandgap with increasing dopant concentrations, particularly in Ag-doped samples. Notably, 0.75Ag-0.25Pr-HAp exhibited the smallest bandgap of 3.983 eV, indicating enhanced electronic conductivity and potential applications in bioelectronics and medical sensors. Furthermore, the co-doped samples demonstrated reduced crystallinity, larger crystallite sizes, and excellent stability in biological environments, alongside superior biocompatibility and antibacterial properties. Among the synthesized materials, 0.75Ag-0.25Pr-HAp exhibited promising characteristics as a biomedical material for bone-related applications, owing to its structural stability, enhanced electrical properties, and suitability in antibacterial and bioelectronic devices. This investigation highlights the versatility of Zn/Ag co-doped Pr-HAp materials for advanced biomedical and technological applications.Öğe İtriyum Katkılı Gadolinyum Oksit Numunelerinin Sentez ve Karakterizasyonu(2022) Ates, Tankut; Korkmaz, Aydan Aksoğan; BULUT, NİYAZİ; KESER, Serhat; KAYGILI, OMERBu çalışmada, yaş kimyasal sentez ile üretilen katkısız ve itriyum (Y) katkılı gadolinyum oksit (Gd2O3) yapıların karakterizasyonu hakkında detaylı bilgi sunuldu. Numunelerin karakterizasyonu için, X-ışını kırınımı analizi, Fourier dönüşümlü kızılötesi spektroskopisi ve taramalı elektron mikroskopi tekniği kullanıldı. Örgü parametresinin, kristal büyüklüğünün ve kristalleşme derecesinin Y miktarıyla değişim gösterdiği gözlendi. Numunelerin kristal büyüklükleri, 31,17 nm ile 35,49 nm aralığında hesaplandı. Numunelerin kristalleşme değerleri, % 88,6 ile % 90,2 aralığında bulunmuştur. Gd2O3’ün morfolojisinin Y miktarından etkilendiği belirlendi.Öğe Ni Katkısının Fe2O3’ün Yapısal Özellikleri Üzerine Etkilerinin Araştırılması(2021) Ates, Tankut; Koytepe, Suleyman; BULUT, NİYAZİ; KAYGILI, OMERSunulan çalışmada, Ni katkısının yaş kimyasal yöntemle hazırlanan Fe2O3’ün yapısal özellikleri üzerine etkileri X-ışını kırınımı (XRD), Fourier dönüşümlü kızılötesi (FTIR), diferansiyel termal analiz (DTA), termogravimetrik analiz (TGA) ve taramalı elektron mikroskopisi (SEM) teknikleri kullanılarak araştırıldı. XRD ve FTIR sonuçları her bir numune için Fe2O3 yapının oluşumunu destekledi. 4at.%Ni katkısına kadar yeni bir faz oluşumu gözlenmedi ve bu numune için NiO ikincil fazının oluşumu tespit edildi. Kristal yapı ilişkili parametreler ve morfoloji, Ni içeriğinden etkilendi. Özetle Ni, Fe2O3 yapının bazı özelliklerini kontrol etmek için kullanılabilir.
