# Tetramer Orbital-Ordering induced Lattice-Chirality in Ferrimagnetic, Polar MnTi2O4

## TL;DR

This study combines density-functional theory and experiments to reveal a unique tetragonal, polar, and chiral lattice ground state in MnTi2O4, driven by orbital ordering and magnetic interactions.

## Contribution

It uncovers a novel tetragonal orbital-ordered ground state with lattice chirality in MnTi2O4, linking structural, magnetic, and orbital phenomena.

## Key findings

- Structural transition to polar P4_1 tetragonal phase at 164 K
- Paramagnetic to ferrimagnetic transition at 45 K
- Lattice chirality arising from Ti-Ti bond-length modulations

## Abstract

Using density-functional theory calculations and experimental investigations on structural, magnetic and dielectric properties, we have elucidated a unique tetragonal ground state for MnTi2O4, a Ti^{3+} (3d^1)-ion containing spinel-oxide. With lowering of temperature around 164 K, cubic MnTi2O4 undergoes a structural transition into a polar P4_1 tetragonal structure and at further lower temperatures, around 45 K, the system undergoes a paramagnetic to ferrimagnetic transition. Magnetic superexchange interactions involving Mn and Ti spins and minimization of strain energy associated with co-operative Jahn-Teller distortions plays a critical role in stabilization of the unique tetramer-orbital ordered ground state which further gives rise to lattice chirality through subtle Ti-Ti bond-length modulations.