Article
Chemistry, Physical
Alexandre Mesquita, Elio Thizay Magnavita Oliveira, Hugo Bonette de Carvalho
Summary: Gadolinium-doped strontium titanate (Sr1-xGdxTiO3) is a perovskite structure material with interesting thermomechanical, termoelectrical, and electrochemical properties. X-ray absorption spectroscopy was used to analyze the local and electronic structure of Sr1-xGdxTiO3 samples, showing that increasing Gd content causes disorder and leads to a small displacement of Ti atoms. Changes in the XANES spectra at O K-edge for Sr1-xGdxTiO3 samples are influenced by the increase in Gd concentration.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Parasmani Manju, Parasmani Rajput, Ankush Vij, Anup Thakur
Summary: This study presents a detailed analysis of the local electronic structure of host and dopant atoms in doping-assisted lattice site engineering through combined experimental and simulated X-ray absorption near edge structure. The results reveal that at low doping concentration, Dy tends to substitute the less symmetric Sr2+ site, while with an increase in doping concentration, Dy starts substituting the relatively more symmetric Zn2+ lattice site. The study deciphers the effect of lattice site occupancy on the local electronic structure of host and dopant atoms.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Veronica Celorrio, Andrew S. Leach, Haoliang Huang, Shusaku Hayama, Adam Freeman, David W. Inwood, David J. Fermin, Andrea E. Russell
Summary: The study utilized in situ X-ray absorption and emission spectroscopies to examine the role of Mn ions in determining the oxygen reduction activity of LaMnO3 and CaMnO3. Results showed differences in redox behavior and oxygen vacancies between the two materials at various applied potentials. The findings have implications for understanding pseudocapacitive response and material degradation processes.
Article
Materials Science, Multidisciplinary
Yi-Ying Chin, Zhiwei Hu, Yuichi Shimakawa, Junye Yang, Youwen Long, A. Tanaka, Liu Hao Tjeng, Hong-Ji Lin, Chien-Te Chen
Summary: Using soft x-ray absorption spectroscopy, the charge and spin states of transition metal ions in YCu3Co4O12 and CaCu3Co4O12 were determined. The low-spin trivalent nature of Cu and Co ions in both materials make them nonmagnetic band semiconductors. The good electrical conductivity of CaCu3Co4O12 is attributed to the presence of low-spin Co ions, allowing for efficient charge exchange between Co3+ and Co4+.
Article
Physics, Condensed Matter
Yoshiya Yamamoto, Hitoshi Yamaoka, Takuma Kawai, Masahiro Yoshida, Jun-ichi Yamaura, Kenji Ishii, Seiichiro Onari, Takayuki Uozumi, Atsushi Hariki, Munetaka Taguchi, Kensuke Kobayashi, Jung-Fu Lin, Nozomu Hiraoka, Hirofumi Ishii, Ku-Ding Tsuei, Hiroshi Okanishi, Soshi Iimura, Satoru Matsuishi, Hideo Hosono, Jun'ichiro Mizuki
Summary: The study reveals differences in electronic and crystal structures of LaFeAsO and SmFeAsO iron-based superconductors under pressure, with the superconductivity of LaFeAsO closely related to a lower spin state and the structural parameters of SmFeAsO holding near optimum values.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
Yu Song, Weiyi Wang, Eugenio Paris, Xingye Lu, Jonathan Pelliciari, Yi Tseng, Yaobo Huang, Daniel McNally, Marcus Dantz, Chongde Cao, Rong Yu, Robert J. Birgeneau, Thorsten Schmitt, Pengcheng Dai
Summary: Iron-based superconductors are magnetically ordered bad metals, with superconductivity appearing near a putative magnetic quantum critical point. The NaFe1-xCuxAs series provides a platform to investigate the connection between superconductivity, magnetism, and electronic correlations. By studying the valence state of Fe and spin dynamics in two NaFe1-xCuxAs compounds, it is concluded that the spin dynamics in NaFe0.53Cu0.47As arise from localized magnetic moments.
Article
Materials Science, Ceramics
F. H. Bhat, G. Anjum, Ravi Kumar, Manzoor A. Malik, R. J. Choudhary, D. K. Shukla
Summary: Polycrystalline LaMn1-xCoxO3 (0.1 <= x <= 0.5) samples synthesized using conventional ceramic method exhibit strong magnetic properties with double transition and spin glass state. These characteristics are mainly influenced by the interactions between Co and Mn ions, showing significant magnetoresistance effects.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Physical
Alexander Okotrub, Dmitriy Gorodetskiy, Yuri N. Palyanov, Dmitry A. Smirnov, Lyubov G. Bulusheva
Summary: By controlling the transformation process of diamond into graphite at elevated temperatures, sp2/sp3 carbon hybrids can be created. This study examines the effect of a thin iron film coating on the reconstruction of a (100) diamond face. Various spectroscopic and microscopy techniques were used to analyze the electronic and structural changes on the diamond surface. The results show the formation of thin sp2-carbon fragments on the clean diamond surface and ordered graphite planes on the iron-coated surface. Iron catalyzes the transformation of diamond into graphitic layers growing vertically relative to the (100) face.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Optics
Hui Hu, Xia-Ji Liu
Summary: We conducted a systematic study on a mobile impurity immersed in a three-dimensional Fermi sea of fermions at finite temperature. By using the standard non-self-consistent many-body T-matrix theory, we determined the impurity spectral function and avoided potential errors in previous calculations. The results showed that the quasiparticle decay rate of both attractive and repulsive polarons does not increase significantly with increasing temperature in the weak-coupling limit, while near the unitary limit with strong coupling, the decay rate of Fermi polarons rapidly increases and the quasiparticle picture breaks down close to the Fermi temperature.
Article
Physics, Condensed Matter
Yoshiya Yamamoto, Hitoshi Yamaoka, Takayuki Uozumi, Atsushi Hariki, Seiichiro Onari, Jun-ichi Yamaura, Kenji Ishii, Takuma Kawai, Masahiro Yoshida, Munetaka Taguchi, Kensuke Kobayashi, Jung-Fu Lin, Nozomu Hiraoka, Hirofumi Ishii, Ku-Ding Tsuei, Hiroshi Okanishi, Soshi Iimura, Satoru Matsuishi, Hideo Hosono, Jun'ichiro Mizuki
Summary: The electronic and crystal structures of LnFeAsO (1-x) H (x) (Ln = La, Sm) compounds were investigated, revealing a reduction in intensity of pre-edge peaks near the Fe-K edge on doping, attributed to weaker As-Fe hybridization. The analysis of integrated-absolute difference (IAD) showed a significant increase in Sm, indicating enhanced magnetic moment of Fe 3d electrons in the higher doped region, contributing to the single dome superconducting phase in Sm.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Chemistry, Multidisciplinary
Ziyi Chen, Andrew G. Walsh, Xiao Wei, Manzhou Zhu, Peng Zhang
Summary: This study investigates the electronic properties of Ag-25(SR)(18) and Au-25(SR)(18) and develops a unique method to analyze the charge transfer behavior of nanoclusters. Experimental X-ray spectroscopy is used to demonstrate the bonding properties of silver nanoclusters, with the staple motif shown to have a significant impact on their electronic properties. The effective X-ray analysis techniques developed here provide new opportunities for the site-specific study of other nanoclusters.
Article
Physics, Multidisciplinary
Norimasa Sasabe, Motoi Kimata, Tetsuya Nakamura
Summary: In this study, XMCD signal was observed from compensated two-dimensional triangle AFM structures on a Kagome lattice, based on the different absorption coefficients of the three sublattices and the sign of the spin chirality. This XMCD signal is only present when the spin chirality is negative, reflecting the unique charge density anisotropies and directions of spin and orbital magnetic moments in the system.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Physical
Jiatang Chen, Y. Zou Finfrock, Zhiqiang Wang, Tsun-Kong Sham
Summary: This study uses advanced techniques to analyze the Pt whitelines and density of states relationship for Pt-Ni and Pt-Cu bimetallic systems. The linear correlation between the whiteline area and unoccupied Sd states allows for a straightforward way to determine the number of unoccupied Pt 5d states. This finding challenges previous assumptions and provides guidance for XAFS experiment design and charge redistribution implications.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
Nick Traeger, Filip Lisiecki, Robert Lawitzki, Markus Weigand, Hubert Glowinski, Gisela Schuetz, Guido Schmitz, Piotr Kuswik, Maciej Krawczyk, Joachim Graefe, Pawel Gruszecki
Summary: This study investigates the emission and propagation of spin waves in magnonic waveguides using time-resolved scanning transmission x-ray microscopy, combined with an isofrequency contour analysis to explain the origin of spin wave excitation and its behavior at the domain interface. Micromagnetic simulations successfully validate the experimental findings, clarifying the fundamental emission mechanisms in magnonic waveguides for future magnonic operations.
Article
Physics, Multidisciplinary
Y. Shen, J. Sears, G. Fabbris, J. Li, J. Pelliciari, I Jarrige, Xi He, I Bozovic, M. Mitrano, Junjie Zhang, J. F. Mitchell, A. S. Botana, V Bisogni, M. R. Norman, S. Johnston, M. P. M. Dean
Summary: The essential electronic properties of low valence nickelates have been debated, whether they have appreciable oxygen charge-transfer character or are in a distinct Mott-Hubbard regime. Using O K-edge resonant inelastic x-ray scattering (RIXS), this study resolved the question and found that the low valence nickelate possesses mixed charge-transfer-Mott-Hubbard character. Despite a similar Coulomb repulsion, the transition-metal-oxygen hopping is larger in the nickelate, leading to a significant superexchange interaction and hole occupation of ligand O orbitals.