Oxygen Chemical Diffusion Coefficient in Manganite Thin Films by Isothermal Electric Resistivity Measurements

TL;DR

This study measures oxygen diffusion coefficients in manganite thin films using isothermal resistivity, revealing differences based on film orientation and providing activation energies for diffusion.

Contribution

It introduces a method to determine oxygen diffusion coefficients in manganite thin films through isothermal conductivity measurements, highlighting the influence of film orientation.

Findings

Diffusion coefficients around 10^-14 cm^2/s.

Faster diffusion in c-oriented films.

Different activation energies for different orientations.

Abstract

In this paper we report the determination of oxygen diffusion coefficient for optimally doped manganite thin films of La0.85Na0.15MnO3 (LNMO). The study was performed by means of isothermal conductivity measurements on two different epitaxially oriented thin films grown on SrTiO3 (100) and SrTiO3 (110). The values found for the oxygen diffusion coefficients are around 10-14 cm2s-1. The diffusion seems to be faster for the c-oriented film with respect to the other one (growth on SrTiO3 (110)). The activation energy for the diffusion process is 0.35 eV for the LNMO film on SrTiO3 (100) and 0.66 for the LNMO film on SrTiO3 (110). A possible reason to account for the different behaviour between the two films is proposed.