X-ray photoemission characterization of La_{0.67}(Ca_{x}Sr_{1-x})_{0.33}MnO_{3} films

TL;DR

This study investigates how the Curie temperature and x-ray photoemission spectra of La_{0.67}(Ca_{x}Sr_{1-x})_{0.33}MnO_{3} films vary with Ca/Sr ratio, revealing compositional effects on electronic structure and magnetic properties.

Contribution

It provides new insights into the relationship between composition, electronic structure, and magnetic transition temperature in LCSMO thin films.

Findings

Curie temperature remains around 300 K across compositions.

Mn-O valence peaks shift with Ca/Sr ratio.

Core lines are linear combinations of pure LCMO and LSMO lines.

Abstract

The Curie temperature and x-ray photoemission spectra of thin films of La_{0.67}(Ca_{x}Sr_{1-x})_{0.33}MnO_{3} (LCSMO) have been studied as a function of the Ca/Sr ratio. The films were grown by off-axis cosputtering from individual targets of La_{0.67}Ca_{0.33}MnO_{3} (LCMO) and La_{0.67}Sr_{0.33}MnO_{3} (LSMO) onto (100) oriented NdGaO_{3} substrates. The films grow with a (100) orientation, with no other orientations observed by x-ray diffraction. For the alloy mixtures, the Curie temperature, T_C, varies slowly as the Ca/Sr is decreased, remaining $\approx$ 300 K, while for the LCMO and LSMO films T_C is 260 and 330 K, respectively. The Mn-O valence structure is composed of two dominant peaks, whose positions undergo a change as the Ca fraction is decreased. The core lines behave as linear combinations of lines from pure LCMO and LSMO.