Eur. Phys. J. B (2012) 85: 82
https://doi.org/10.1140/epjb/e2012-21067-6

Regular Article

Magnetism and unusual Cu valency in quadruple perovskites

¹ CNR-ISM, Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via Salaria km 29.5 CP 10, 00016 Monterotondo Stazione, Italy
² Dipartimento di Fisica, Università di Cagliari and CNR-IOM, UOS Cagliari, Cittadella Universitaria, 09042 Monserrato ( CA), Italy

^a e-mail: vincenzo.fiorentini@dsf.unica.it

Received: 23 December 2011
Received in final form: 28 January 2012
Published online: 29 February 2012

Abstract

We study a selection of Cu-containing magnetic quadruple perovskites (CaCu₃Ti₄O₁₂ LaCu₃Fe₄O₁₂, and YCu₃Co₄O₁₂) by ab initio calculations, and show that Cu is in an effective divalent Cu(II)-like state or a trivalent Cu(III) state depending on the choice of octahedral cation. Based on the electronic structure, we also discuss the role of Mott and Zhang-Rice physics in this materials class.