Soft-Chemical Synthesis, Structure Evolution, and Insulator-to-Metal Transition in Pyrochlore-like λ-RhO2
Year: 2024
Type: article
Abstract: λ-RhO 2, a prototype 4d transition metal oxide, has been prepared by the oxidative delithiation of spinel LiRh 2 O 4 using ceric ammonium nitrate. Average-structure studies of this RhO 2 polytype, including synchrotron powder X-ray diffraction and electron diffraction, indicate the room-temperature structure to be tetragonal, in space group I 4 1 / amd, with a first-order structural transition to cubic Fd 3̅ m at T = 345 K on warming. Synchrotron X-ray pair distribution function analysis and 7 Li solid-state nuclear magnetic resonance measurements suggest that the room-temperature structure displays local Rh–Rh bonding. The formation of these local dimers appears to be associated with a metal-to-insulator transition with a nonmagnetic ground state, as also supported by density functional theory-based electronic structure calculations. This contribution demonstrates the power of soft chemistry to kinetically stabilize a simple binary oxide compound.
Source: Chemistry of Materials
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, University of California, Santa Barbara, Materials Research Science and Engineering Center, Harvard University, Division of Materials Research, Basic Energy Sciences, California NanoSystems Institute, Division of Materials Sciences and Engineering
Awards: G1110399006, G1141670404, G17160138, G2232042528, Discovery-Driven Search for Polar Electronic Phases, G2760720504, Materials Research Science and Engineering Center at UCSB, G3349485200, G3400352658, G3436026233, G401861217, PHONONS AND ELECTRONS IN THIN COMPLEX OXIDES, G4281768896, G4394554495, G563325747, G6569974432, G6692005437, INTRINSIC TOPOLOGICAL SUPERCONDUCTORS FOR NEXT-GENERATION QUANTUM SYSTEMS, G8156022189, MRI: Acquisition of a High Performance Central Computing Facility at University of California Santa Barbara
OpenAlex ID: W4390976309