# Unusual magnetic structure of high-pressure synthesized perovskites ACrO3(A=Sc, In, Tl)

## TL;DR

This study reveals that metastable high-pressure synthesized perovskites ScCrO3, InCrO3, and TlCrO3 exhibit a C-type magnetic structure, differing from typical G-type, driven by specific exchange interactions and structural distortions.

## Contribution

It uncovers the unique C-type magnetic ordering in these metastable perovskites and explains its origin through first-principles calculations and structural analysis.

## Key findings

- ScCrO3 and InCrO3 have ferromagnetic nearest-neighbor interactions.
- TlCrO3's magnetic order is stabilized by strong next-nearest-neighbor antiferromagnetic exchange.
- The magnetic spins align along the orthorhombic b-axis due to single ion anisotropy.

## Abstract

Magnetic structures of metastable perovskites ScCrO3, InCrO3 and TlCrO3, stabilized under high-pressure and high-temperature conditions, have been studied by neutron powder diffraction. Similar to the other orthochromites LnCrO3 (Ln=lanthanide or Y), these materials crystallize into the orthorhombic structure with Pnma10 symmetry. The spin configuration of the metastable perovskites has been found to be C-type, contrasting with the G-type structure usually observed in LnCrO3. First-principles calculations demonstrate that the Ctype structure found in ScCrO3 and InCrO3 is attributed to a ferromagnetic (FM) nearest-neighbor interaction, while in TlCrO3, this type of magnetic ordering is stabilized by a strong next-nearest-neighbor antiferromagnetic (AFM) exchange. The spins in the C-type magnetic structure line up along the orthorhombic b-axis, yielding the Pnma magnetic symmetry. The dominant mechanism controlling this spin direction has been concluded to be the single ion anisotropy imposed by a uniaxial distortion of CrO6 octahedra.