Effects of annealing and strain on La_{1-x}Ca_{x}MnO_{3} thin films: a new phase diagram in the ferromagnetic region

TL;DR

This study investigates how annealing and strain influence the properties of La_{1-x}Ca_{x}MnO_{3} thin films, leading to a proposed new phase diagram that accounts for oxygen content and structural effects beyond the bulk phase diagram.

Contribution

It introduces a new phase diagram for La_{1-x}Ca_{x}MnO_{3} thin films considering oxygen content and structural changes, extending understanding beyond bulk properties.

Findings

Optimized properties achieved after oxygen annealing for some compositions.

Changes in oxygen content cause structural modifications and self-doping effects.

Proposed a new phase diagram for thin film properties beyond bulk phase behavior.

Abstract

Oriented, single phase thin films of La_{1-x}Ca_{x}MnO_{3} have been deposited onto (100)-oriented LaAlO_{3} (0.1<x<0.5) substrates using the Pulsed Laser Deposition technique. While for some compositions the physical properties (transport and magnetization) of the as-grown films are higher than the bulk values, for other calcium contents the optimized properties are obtained only after annealing under oxygen. These data can be partly explained by changes in oxygen content, resulting in cationic vacancies and thus self-doping effects - accompanying structural changes, may be the cause of properties beyond the phase diagram. We propose a new phase diagram for (La_{1-x}Ca_{x})_{1-y}\square_{y}MnO_{3} (0.1<x<0.5) thin films.