Thickness dependent magnetotransport in ultra-thin manganite films

TL;DR

This study investigates how the magnetotransport properties of ultra-thin La_{0.67}Sr_{0.33}MnO_3 films depend on thickness, revealing the presence of a dead layer affecting magnetic and electronic behavior.

Contribution

It provides the first detailed analysis of thickness-dependent magnetotransport in ultra-thin manganite films, quantifying the dead layer thickness on different substrates.

Findings

Dead layer thickness is approximately 30 Å on NdGaO_3.

Dead layer thickness is approximately 50 Å on LaAlO_3.

Magnetotransport properties are significantly influenced by film thickness.

Abstract

To understand the near-interface magnetism in manganites, uniform, ultra-thin films of La_{0.67}Sr_{0.33}MnO_3 were grown epitaxially on single crystal (001) LaAlO_3 and (110) NdGaO_3 substrates. The temperature and magnetic field dependent film resistance is used to probe the film's structural and magnetic properties. A surface and/or interface related dead-layer is inferred from the thickness dependent resistance and magnetoresistance. The total thickness of the dead layer is estimated to be $\sim 30 \AA$ for films on NdGaO_3 and $\sim 50 \AA$ for films on LaAlO_3.