Open AccessOn the energy scale involved in the metal to insulator transition of quadruple perovskite EuCu3Fe4O12: infrared spectroscopy and ab-initio calculations
Author(s) -
Benjamin Brière,
Aleksandr Kalinko,
Ikuya Yamada,
Pascale Roy,
J.-B. Brubach,
R. Sopracase,
Mustapha Zaghrioui,
V. Ta Phuoc
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep28624
Subject(s) - optical conductivity , ab initio , perovskite (structure) , materials science , spectroscopy , isostructural , band gap , infrared , conductivity , infrared spectroscopy , condensed matter physics , chemistry , crystallography , physics , crystal structure , optics , organic chemistry , quantum mechanics
Optical measurements were carried out by infrared spectroscopy on AA′ 3 B 4 O 12 A-site ordered quadruple perovskite EuCu 3 Fe 4 O 12 (microscopic sample) as function of temperature. At 240 K (=T MI ), EuCu 3 Fe 4 O 12 undergoes a very abrupt metal to insulator transition, a paramagnetic to antiferromagnetic transition and an isostructural transformation with an abrupt large volume expansion. Above T MI , optical conductivity reveals a bad metal behavior and below T MI , an insulating phase with an optical gap of 125 meV is observed. As temperature is decreased, a large and abrupt spectral weight transfer toward an energy scale larger than 1 eV is detected. Concurrently, electronic structure calculations for both high and low temperature phases were compared to the optical conductivity results giving a precise pattern of the transition. Density of states and computed optical conductivity analysis identified Cu 3 dxy , Fe 3 d and O 2 p orbitals as principal actors of the spectral weight transfer. The present work constitutes a first step to shed light on EuCu 3 Fe 4 O 12 electronic properties with optical measurements and ab-initio calculations.