Electronic Transitions in Strained SmNiO_3 Thin Films

TL;DR

This study explores how epitaxial strain influences the electronic and magnetic phase transitions in SmNiO_3 thin films, revealing strain-induced suppression and modification of the metal-insulator and magnetic transitions.

Contribution

It demonstrates the impact of epitaxial strain on the phase behavior of SmNiO_3, showing how strain can tune the transition temperatures and phases.

Findings

Compressive strain alters the relation between T_Néel and T_MI.

Small compressive strain leads to T_Néel=T_MI and first-order MIT.

High compressive strain stabilizes a metallic paramagnetic phase.

Abstract

Nickelates are known for their metal to insulator transition (MIT) and an unusual magnetic ordering, occurring at T=T_N\'eel. Here, we investigate thin films of SmNiO_3 subjected to different levels of epitaxial strain. We find that the original bulk behavior (T_N\'eel<T_MI) is strongly affected by applying compressive strain to the films. For small compressive strains, a regime where T_N\'eel=T_MI is achieved, the paramagnetic insulating phase characteristic of the bulk compound is suppressed and the MIT becomes 1st order. Further increasing the in-plane compression of the SmNiO_3 lattice leads to the stabilization of a single metallic paramagnetic phase.