Structural transitions and transport-half-metallic ferromagnetism in LaMnO3 at elevated pressure

iangang He1, Ming-Xing Chen2, Xing-Qiu Chen3, and Cesare Franchin

1Faculty of Physics, University of Vienna and Center for Computational Materials Science, A-1090 Wien, Austria

 2Faculty of Chemistry, University of Vienna and Center for Computational Materials Science, A-1090 Wien, Austria

 Shenyang National Laboratory for Materials Science, Institute of Metal Research,Chinese Academy of Sciences, Shenyang 110016, China

(Dated: November 5, 2018)

Abstract

By means of hybrid density functional theory we investigatethe evolution of the structural, elec-tronic and magnetic properties of the colossal magnetoresistance (CMR) parent compound LaMnO3under pressure. We predict a transition from a low pressure antiferromagnetic (AFM) insulator toa high pressure ferromagnetic (FM) transport half-metal (tHM), characterized by a large spin po-larization (≈80-90 %). The FM-tHM transition is associated with a progressive quenching of thecooperative Jahn-Teller (JT) distortions which transformtheP nmaorthorhombic phase into a per-fect cubic one (through a mixed phase in which JT-distorted and regular MnO6octahedra coexist),and with a high-spin (S= 2,mMn=3.7μB) to low-spin (S= 1,mMn=1.7μB) magnetic moment col-lapse. These results interpret the progression of the experimentally observed non-Mott metalizationprocess and open up the possibility of realizing CMR behaviors in a stoichiometric manganite.

https://arxiv.org/pdf/1205.1303.pdf