Room temperature multiferroism in CaTcO$_3$ by interface engineering

TL;DR

This paper demonstrates that interface engineering in CaTcO$_3$/BaTcO$_3$ superlattices can induce room temperature multiferroicity by suppressing octahedral rotations, revealing a new pathway for designing multiferroic materials.

Contribution

It introduces a novel interface engineering approach to recover ferroelectricity in CaTcO$_3$, enabling room temperature multiferroicity.

Findings

CaTcO$_3$ exhibits weak ferroelectricity and large octahedral rotations.

Interface engineering suppresses octahedral rotations and restores ferroelectricity.

CaTcO$_3$ can be a room temperature multiferroic with a N{é}el temperature of about 816 K.

Abstract

The structural instabilities of ATcO$_3$(A= Ca, Sr, Ba) are investigated by first-principles calculations. In addiction to the large octahedral rotation instability, a weak ferroelectric tendency is identified in CaTcO$_3$. We show that the ferroelectricity in CaTcO$_3$ can be recovered by interface engineering based on CaTcO$_3$/BaTcO$_3$ superlattices, where the octahedral rotation is largely suppressed. The N{\'e}el temperature is found to be $\sim$ 816 K, indicating that CaTcO$_3$ can be engineered into a new room temperature multiferroic material.