Composition dependence of electronic, magnetic, transport and morphological properties of mixed valence manganite thin films

TL;DR

This study investigates how electronic, magnetic, and morphological properties of mixed valence manganite thin films depend on composition, revealing different correlation lengths near the metal-insulator transition through combined spectroscopic and scattering techniques.

Contribution

It provides a comparative analysis of charge and magnetic correlation lengths in manganite thin films with different compositions using advanced x-ray scattering methods.

Findings

Charge-magnetic correlation length is ~4 times larger than charge-charge at x=0.33.

At x=0.375, charge-magnetic and charge-charge lengths are comparable.

Correlation lengths vary significantly with composition and temperature.

Abstract

We present a comparison of the in-plane length scale over which charge and magnetism are correlated in (La0.4Pr0.6)1-xCaxMnO3 films with x = 0.33 and 0.375, across the metal to insulator transition (MIT) temperature. We combine electrical transport (resistance) measurements, x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD), and specular/off-specular x-ray resonant magnetic scattering (XRMS) measurements as a function of temperature to elucidate relationships between electronic, magnetic and morphological structure of the thin films. Using off-specular XRMS we obtained the charge-charge and charge-magnetic correlation length of these LPCMO films near the MIT. The charge-magnetic correlation length (~ 12000 {\AA}) for x = 0.33 was much larger (~4 times) than the charge-charge correlation length (~ 3200 {\AA}) at 20 K. Whereas for x = 0.375 the charge-magnetic correlation length (~ 7500 {\AA}) was smaller than the charge-charge correlation length (~ 9000 {\AA}).