We have synthesized a new spinel oxide LiRh2O4 with a mixed-valent configuration of Rh3+ and Rh4+. At room temperature, it is a paramagnetic metal, but on cooling, a metal-insulator transition occurs and a valence bond solid state is formed below 170 K. We argue that the formation of valence bond solid is promoted by a band Jahn-Teller transition at 230 K and the resultant confinement of t_{2g} holes within the xy band. The band Jahn-Teller instability is also responsible for the observed enhanced thermoelectric power in the orbital-disordered phase above 230 K.
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http://dx.doi.org/10.1103/PhysRevLett.101.086404 | DOI Listing |
J Colloid Interface Sci
March 2025
Hunan Province Key Laboratory of Chemical Power Source, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China; Innovation Base of Energy and Chemical Materials for Graduate Students Training, Central South University, Changsha 410083, China. Electronic address:
Manganese oxide is a promising cathode material for rechargeable batteries due to its high theoretical specific capacity. However, its practical application is hindered by its poor conductivity and rapid capacity decay caused by Jahn-Teller distortion during charging and discharging. This work introduces NaEDTA during the synthesis of MnO, and the amino group is introduced by adsorption to deposit to form N-doped MnO.
View Article and Find Full Text PDFChem Mater
October 2024
Department of Materials, University of California, Santa Barbara, California 93106, United States.
Vacancy-ordered double perovskites with the formula (where is a +1 cation, is a +4 metal, and is a halide ion) offer improved ambient stability over other main-group halide perovskites and potentially reduced toxicity compared to those containing lead. These compounds are readily formed through a number of synthetic routes; however, the manner in which the synthetic route affects the resulting structure or optoelectronic properties has not been examined. Here, we investigate the role of distinct precursors and solvents in the formation of the indirect band gap vacancy-ordered double perovskite CsTeBr.
View Article and Find Full Text PDFJ Chem Phys
October 2024
HSE University, Moscow 101000, Russia.
Broadband blue emission in zero-dimensional perovskites has received considerable attention, which is very important for the realization of stable blue-light emitters; however, the underlying formation mechanism remains unclear. Based on first-principles calculations, we have systematically studied the self-trapped excitons (STEs) behavior and luminescence properties in 0D-(DMA)4PbI6 perovskite. Our calculations show that there is a significant difference between the intrinsic STE luminescence mechanism (∼2.
View Article and Find Full Text PDFJ Chem Phys
October 2024
Department of Chemical Science, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India.
Nonadiabatic quantum dynamics are carried out to illustrate the photoionized spectrum of the cyanopropyne (CH3-C≡C-C≡N) as reported in recent experimental measurements [Lamarre et al., J. Mol.
View Article and Find Full Text PDFACS Nano
September 2024
School of Chemistry and Chemical Engineering, Hefei University of Technology, 230009 Hefei, Anhui, P. R. China.
Enhancing proton storage in the zinc-ion battery cathode material of MnO holds promise in promoting its electrochemical performance by mitigating the intense Coulombic interaction between divalent zinc ions and the host structure. However, challenges persist in addressing the structural instability caused by Jahn-Teller effects and accurately modulating H intercalation in MnO. Herein, the doping of high-electronegativity Sb with fully occupied d-orbital in MnO is reported.
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