The 3d-electron states in LaMnO3*

TL;DR

This paper advocates for a localized atomic-like crystal-field model to describe the 3d electron states in LaMnO3, providing a discrete energy spectrum that explains its insulating and magnetic properties more effectively than band theories.

Contribution

It introduces a novel atomic-like approach incorporating Hund's rules, spin-orbit coupling, and Jahn-Teller distortion to model LaMnO3's electronic structure, contrasting with existing band theory models.

Findings

The model explains LaMnO3's insulating ground state.

It accounts for magnetic properties using atomic-like states.

The approach aligns with thermodynamic observations.

Abstract

Three fundamentally different electronic structures for 3d electron states in LaMnO3, discussed in the current literature, have been presented. We are in favour of the localized electron atomic-like crystal-field approach that yields the discrete energy spectrum, in the scale of 1 meV, associated with the atomic-like states of the Mn3+ ions in contrary to the continuous energy spectrum yielded by band theories. In our atomic-like approach the d electrons form the highly-correlated electron system 3d4 described by two Hund's rules quantum numbers S=2 and L=2. We take into account the spin-orbit coupling, Jahn-Teller distortion and formation of the magnetic state. The resulting electronic structure is completely different from that presented in the current literature. The superiority of our model relies in the fact that it explains consistently properties of LaMnO3, the insulating and magnetic ground state and thermodynamics, using well-established physical concepts. Keywords: 3d magnetism, Hund's rules, spin-orbit coupling, crystal field, LaMnO3 PACS: No: 71.70.Ej : 75.10.Dg : 73.30.-m