Article
Chemistry, Inorganic & Nuclear
Lana Omar Ahmed, Niyazi Bulut, Luis Banares, Omer Kaygili, Hanifi Kebiroglu, Tankut Ates, Suleyman Koytepe, Burhan Ates
Summary: This work investigates Ce3+ and Er3+ co-doped hydroxyapatite (HAp) structures theoretically and experimentally for the first time. The Ce3+ content was varied incrementally from 0.13 at. % to 0.78 at. %, while the Er3+ content remained constant at 0.39 at. % for all samples. Various analyses were performed, and the results showed that the thermal behavior, morphology, and crystal structure-related parameters were significantly influenced by the concentration of Ce3+. The formation of HAp structures was confirmed through FTIR and Raman spectroscopy, and theoretical calculations revealed changes in density and bandgap with the addition of Ce3+.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
C. Kenel, M. M. F. Al Malki, D. C. Dunand
Summary: This study explores the feasibility of synthesizing thermoelectric materials from oxide precursors, which has the potential to simplify the processing chain and reduce costs to obtain 3D-extruded thermoelectric parts with complex shapes and architectures.
Article
Chemistry, Physical
Lana Omar Ahmed, Niyazi Bulut, Fatih Osmanlioglu, Beyhan Tatar, Hanifi Kebiroglu, Tankut Ates, Suleyman Koytepe, Burhan Ates, Serhat Keser, Omer Kaygili
Summary: The Pr and Er co-doped hydroxyapatites (HAps) were investigated theoretically and experimentally. The Pr content was varied from 0.13% to 0.78%, while the Er content remained constant at 0.39%. Theoretical results showed an increase in density and a decrease in bandgap with increasing Pr content. X-ray diffraction patterns revealed that all samples consisted of a single phase of HAp. The crystallinity decreased gradually with the addition of Pr. The cell viability of all samples was higher than 83%.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Materials Science, Ceramics
Ayano Nakamoto, Kohta Nambu, Hiroshi Masuda, Hidehiro Yoshida
Summary: Undoped Y2O3 polycrystals were densified by flash sintering under DC or AC electric field with varying holding times up to 60 min. The chemical bonding state and crystal structure were investigated by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. DC flash sintering with longer holding times (>= 30 min) resulted in blackening in cathodic regions, indicating the electrode-dependent introduction of neutral oxygen vacancies. The Y 3d3/2 and Y 3d5/2 binding energies decreased with increasing holding time in both DC- and AC-flash-sintered Y2O3 specimens, regardless of polarity, indicating that positively charged oxygen vacancies were introduced by the flash sintering in an electrode-independent manner, even under DC electric field. XRD analysis revealed short-range structural fluctuations in flash-sintered specimens with longer holding times. These electrode-dependent and independent point defect generations under electric fields may be related to the enhanced atomic diffusion during flash sintering.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Physical
S. Thanikaikarasan
Summary: Researchers have prepared cadmoselite thin films using electrodeposition technique, showing high absorbance in optical properties and a band gap value of 1.76 eV.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Ceramics
Housei Akazawa
Summary: This report introduces a method to evaluate the crystallographic orientation and crystallinity of HAp thin films using Raman scattering spectroscopy. By analyzing the Raman spectra, the presence or absence of certain signals can indicate the orientation of HAp crystals. Another approach involves evaluating crystallinity based on the line width of specific Raman signals.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Physical
J. Barta, K. S. Pestovich, J. A. Valdez, B. W. Wiggins, C. Richards, E. Smith, J. H. Clayton, D. Smalley, K. J. McClellan
Summary: Quenching from the melt using an Optical Floating Zone furnace was studied as a high-throughput preparation method for screening novel scintillating materials. Polycrystalline rare-earth aluminum garnets and yttrium gallium aluminum garnets were synthesized and characterized, with Y3Al5O12, LuY2Al5O12, and GdY2Al5O12 identified as having the highest scintillation efficiency among the prepared samples.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Nanoscience & Nanotechnology
Joao V. Campos, Isabela R. Lavagnini, Viviana Avila, Bola Yoon, Sanjit Ghose, Rishi Raj, Eliria M. J. A. Pallone, Lilian M. Jesus
Summary: This study investigates the Arrhenius behavior of electrical conductivity during flash sintering of 3 mol% yttria stabilized zirconia. Total conductivity was found to follow an Arrhenius-like equation in both dense and green samples, with non-linearity related to furnace temperature. A change in activation energy for conduction prior to the flash event was observed and discussed.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
H. Y. Hong, D. H. Kim, S. O. Won, K. Park
Summary: The Ce4+ doping significantly enhances the electrical conductivity of Bi2-xCexO2Se and results in decreased Seebeck coefficient, increased thermal conductivity, and improved thermoelectric properties. Ce4+ doping is highly effective in enhancing the thermoelectric performance of Bi2O2Se.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Materials Science, Multidisciplinary
Wei Liu, Yin Fang, Hangkai Qiu, Changwei Bi, Xiaogu Huang, Sha Lin, Chao Wang, Jin Xu
Summary: This study synthesized HAP samples with different properties by controlling the synthesis conditions and evaluated their photocatalytic performance using machine learning technique. The results showed that the crystallinity of HAP was the dominant factor determining the photocatalytic performance, and the developed machine learning method achieved high accuracy in predicting the catalytic results.
Article
Materials Science, Ceramics
Martin I. Miranda-Lopez, V. Sanchez Rico, M. B. Hernandez, L. Falcon-Franco, S. Garcia-Villarreal, P. Zambrano-Robledo, Miguel Esneider-Alcala, L. Garcia-Ortiz, J. A. Aguilar-Martinez
Summary: The present study systematically investigated the transitions and consequential effects of antimony oxide additions on a SnO2-based varistor system, revealing that the addition of 0.05 mol% antimony oxide provides the foremost properties. Thermal analysis indicated the in-situ formation of Sb2O4 from Sb2O3 or Sb2O5 during sintering, with equivalent amounts of Sb2O4 formed in both cases.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Multidisciplinary
Shuo Feng, Rajesh Kumar Singh, Yucheng Fu, Zhuo Li, Yulong Wang, Jie Bao, Zhijie Xu, Guosheng Li, Cassidy Anderson, Lili Shi, Yuehe Lin, Peter G. Khalifah, Wei Wang, Jun Liu, Jie Xiao, Dongping Lu
Summary: In this study, a simple strategy was demonstrated for constructing low-tortuosity through-pores in both vertical and planar directions of electrodes by casting large particles into single-particle-layer electrodes. Through multi-scale characterizations and simulations, correlations between material/electrode structures, electrolyte permeability, polysulfide migration, and sulfur reactions were elucidated. The high-loading and dense sulfur cathode fabricated by this method delivers a high specific capacity at a very low electrolyte/sulfur ratio.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Brittany Foley, Clement Guibert, Mohamed Selmane, Alberto Mezzetti, Caroline Lefebvre, Karim El Kirat, Jessem Landoulsi
Summary: In this study, the effects of enzyme substrate concentration and fluoride concentration on the obtained minerals in enzyme-assisted mineralization were investigated. X-ray diffraction, infrared spectroscopy, and X-ray photoelectron spectroscopy were used to analyze the crystal structure and chemical composition of the minerals. The results showed the formation of substituted hydroxyapatite in all conditions, with expansion of the crystal unit cell parameters when the enzyme substrate concentration increased, and contraction of the crystal unit cell parameters and the formation of elongated, well-crystallized rods when the fluoride concentration increased. Complementary IR and XPS data indicated that these trends were explained by the incorporation of substituted ions in the hydroxyapatite lattice at different positions.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Sandor Zsurzsa, Moustafa El-Tahawy, Laszlo Peter, Laszlo Ferenc Kiss, Jeno Gubicza, Gyorgy Molnar, Imre Bakonyi
Summary: Electrodeposited Ni65Co35/Cu multilayers with different Cu spacer layer thicknesses were studied for their structure, magnetic properties, and magnetoresistance properties. It was found that the electrochemically optimized Cu deposition potential played a crucial role in controlling the spacer layer thickness and revealing the true evolution of the giant magnetoresistance (GMR) effect. X-ray diffraction analysis showed highly coherent growth of the multilayer stacks. All the multilayers exhibited a GMR effect, which showed a steep rise around 1.5 nm spacer layer thickness and remained nearly constant after 3 nm. The absence of antiferromagnetic coupling between the magnetic layers explained the lack of oscillatory GMR behavior. The occurrence of GMR can be attributed to the decoupling of the adjacent magnetic layers and the random magnetization orientation for spacer layer thicknesses above about 1.5 nm.
Article
Chemistry, Physical
Lana Omar Ahmed, Niyazi Bulut, Hanifi Kebiroglu, Mohammad Alkhedher, Tankut Ates, Suleyman Koytepe, Burhan Ates, Omer Kaygili, ElSayed M. Tag El Din
Summary: This study investigated the yttrium and erbium co-doping in hydroxyapatite structures for the first time using theoretical and experimental methods. The materials were synthesized with varying yttrium concentration and constant erbium concentration, and then tested for spectroscopic, thermal, and biocompatibility properties. The study found that increasing yttrium concentration affected the thermal, morphological, and structural parameters of the materials, while erbium concentration had no significant effect. Theoretical calculations showed that increasing yttrium concentration led to increased density and decreased bandgap energy, except for the sample with 0.39 at.% erbium. Experimental results demonstrated excellent biocompatibility of the prepared samples.
