Large increase of the Curie temperature by orbital ordering control

TL;DR

This paper demonstrates that applying specific strains and layer alternation in manganite thin films can dramatically increase their Curie temperature, confirmed through both first-principles calculations and experimental synthesis.

Contribution

It introduces a novel method of controlling orbital ordering via layered super-lattices to significantly enhance the Curie temperature of manganites.

Findings

Curie temperature increased by over an order of magnitude

Orbital ordering control is achievable through layered super-lattices

Theoretical predictions confirmed by experimental synthesis

Abstract

Using first principle calculations we showed that the Curie temperature of manganites thin films can be increased by far more than an order of magnitude by applying appropriate strains. Our main breakthrough is that the control of the orbital ordering responsible for the spectacular $T_C$ increase cannot be imposed by the substrate only. Indeed, the strains, first applied by the substrate, need to be maintained over the growth direction by the alternation of the manganite layers with another appropriate material. Following these theoretical findings, we synthesized such super-lattices and verified our theoretical predictions.