By means of hybrid density functional theory we investigate the evolution of the structural, electronic and magnetic properties of the colossal magnetoresistance (CMR) parent compound LaMnO3 under pressure. We predict a transition from a low pressure antiferromagnetic (AFM) insulator to a high pressure ferromagnetic (FM) transport half-metal (tHM), characterized by a large spin polarization (~ 80-90 %). The FM-tHM transition is associated with a progressive quenching of the cooperative Jahn-Teller (JT) distortions which transform the Pnma orthorhombic phase into a perfect cubic one (through a mixed phase in which JT-distorted and regular MnO6 octahedra coexist), and with a high-spin (S=2, m_Mn=3.7 mu_B) to low-spin (S=1, m_Mn=1.7 mu_B) magnetic moment collapse. These results interpret the progression of the experimentally observed non-Mott metalization process and open up the possibility of realizing CMR behaviors in a stoichiometric manganite.
@article{arxiv.1205.1303,
title = {Structural transitions and transport-half-metallic ferromagnetism in LaMnO3 at elevated pressure},
author = {J. He and M. -X. Chen and X. -Q Chen and C. Franchini},
journal= {arXiv preprint arXiv:1205.1303},
year = {2012}
}