Ground-state structure, orbital ordering and metal-insulator transition in double-perovskite PrBaMn2O6

Autor: Sergey V. Streltsov, Roman E. Ryltsev, Nikolay M. Chtchelkatchev
Rok vydání: 2022
Předmět:
PEROVSKITE
RARE EARTHS
CHARGE-ORDERING
JAHN-TELLER EFFECT
FOS: Physical sciences
METAL INSULATOR TRANSITION
DOUBLE-PEROVSKITE MANGANITES
GGA + U
Condensed Matter - Strongly Correlated Electrons
BARIUM COMPOUNDS
DIGITAL STORAGE
ORBITAL ORDERING
STRUCTURAL OPTIMIZATION
Materials Chemistry
GGA + U CALCULATION
MANGANITES
RARE-EARTHS
Condensed Matter - Materials Science
Strongly Correlated Electrons (cond-mat.str-el)
DOUBLE PEROVSKITES
Mechanical Engineering
DOUBLE-PEROVSKITE MANGANITE
Metals and Alloys
Materials Science (cond-mat.mtrl-sci)
CRYSTAL SYMMETRY
METAL INSULATOR BOUNDARIES
ORBITAL ORDER
PRASEODYMIUM COMPOUNDS
GROUND STATE
PEROVSKITES MANGANITES
Mechanics of Materials
JAHN-TELLER DISTORTIONS
GROUND-STATE STRUCTURES
GGA + U CALCULATIONS
ORBITS
AFM
METAL-INSULATOR TRANSITION
SEMICONDUCTOR INSULATOR BOUNDARIES
CHARGE ORDERING
Zdroj: Journal of Alloys and Compounds
ISSN: 0925-8388
DOI: 10.1016/j.jallcom.2022.165150
Popis: In recent years, A-site ordered half-doped double-perovskite manganites RBaMn2O6 (R=rare earth) have attracted much attention due to their remarkable physical properties and a prospect of application as magnetoresistive, multiferroic, and oxygen storage materials. The nature of the ground state in RBaMn2O6 as well as sequence of phase transitions taking place at cooling are not yet well understood due to complexity in both experimental and theoretical studies. Here we address the origin of the ground-state structure in PrBaMn2O6 as well as its electronic and magnetic properties. Utilizing GGA+U approach and specially designed strategy to perform structural optimization, we show that the system has two competing AFM-A and AFM-CE magnetic structures with very close energies. The AFM-A structure is a metal, while AFM-CE is an insulator and the transition to the insulating state is accompanied by the charge Mn3+/Mn4+, and orbital 3x2 − r2/3y2 − r2 orderings. This orbital ordering results in strong cooperative Jahn-Teller (JT) distortions, which lower the crystal symmetry. Our findings give a key to understanding contradictions in available experimental data on PrBaMn2O6 and open up the prospects to theoretical refinements of ground-state structures in other RBaMn2O6 compounds. © 2022 Elsevier B.V. Russian Foundation for Basic Research, РФФИ: 118020190095-4, 19-29-12013, AAAA-A18–118020190095-4; Russian Science Foundation, RSF: 18-12-00438, 20-62-46047 We are extremely grateful to P. Maksimov for his comments and to E. Sterkhov providing us with results of high-temperature refinement of crystal structure. We acknowledge support of the Russian Science Foundation via projects 20-62-46047 (study of interplay between charge, spin and orbital degrees of freedom) and 18-12-00438 (structure optimization). Data processing was supported by RFBR (project No 19-29-12013 ) and the Quantum project ( AAAA-A18–118020190095-4 ).. We are extremely grateful to P. Maksimov for his comments and to E. Sterkhov providing us with results of high-temperature refinement of crystal structure. We acknowledge support of the Russian Science Foundation via projects 20-62-46047 (study of interplay between charge, spin and orbital degrees of freedom) and 18-12-00438 (structure optimization). Data processing was supported by RFBR (project No 19-29-12013) and the Quantum project (AAAA-A18?118020190095-4).
Databáze: OpenAIRE
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