Evidence of spin lattice coupling in MnTiO$_{3}$: an x-ray diffraction study

TL;DR

This study investigates the temperature-dependent structural changes in MnTiO₃, revealing spin-lattice coupling effects that influence its magnetic and potential ferroelectric properties through x-ray diffraction and first-principles calculations.

Contribution

It provides new insights into the temperature evolution of structural parameters and spin-lattice interactions in MnTiO₃, highlighting their role in magnetoelectric behavior.

Findings

Structural parameters vary with temperature in three distinct regions.

Spin-lattice coupling influences magnetic interactions and structural changes.

First-principles calculations align with experimental observations.

Abstract

Here we investigate the temperature evolution of the structural parameters of a potential magnetoelectric material, MnTiO$_{3}$. The experimental results reveal interesting temperature dependence of the $c/a$ ratio and the Mn-O bonds which can be divided into three regions. In region I (300 K to 200 K), the above parameters are seen to decrease with decrease in temperature due to thermal effect. In the region II (200 K to 95 K), the decrement in the structural parameters are reduced due the competing intra layer antiferromagnetic interaction setting in $\sim$ 200 K. The $c/a$ ratio are seen to display a minima around 140 K. Below 140 K, the short Mn-O bonds increase suggesting the onset of inter layer antiferromagnetic interaction $\sim$ 100 K. In region III (95 K to 23 K), the antiferromagnetic interaction is fully established. The behaviour of the calculated Mn-O bonds based on first principle calculations are in line with the experimental results. This study demonstrates the importance of spin lattice coupling in understanding the magnetic properties of the compound which is expected to be helpful in revealing the origin of magnetically induced ferroelectricity.