Peak resistance temperature and low temperature resistivity in thin film $La_{1-x} Ca_x Mn O_3$ mixtures for x <= 1/3

TL;DR

This study investigates the electrical resistivity and peak resistance temperature of La$_{1-x}$Ca$_{x}$MnO$_{3}$ thin films with varying calcium doping, revealing complex relationships with polaronic hopping and impurity scattering.

Contribution

It provides new insights into the correlation between resistance temperature peaks and polaronic hopping energy, and models low temperature resistivity with single magnon scattering in thin films.

Findings

Peak resistance temperature correlates with polaronic hopping energy.

Low temperature resistivity fits a single magnon scattering model.

Resistivity due to magnon scattering correlates with static impurities.

Abstract

The electrical resistivity of La$_{1-x}$Ca$_{x}$MnO$_{3}$ thin films grown on (001) NdGaO$_{3}$ and (100) SrTiO$_{3}$ substrates by off-axis sputtering has been studied as a function of the Calcium doping level. The samples have very narrow rocking curves and excellent in plane registry with the substrate. A strong correlation between the peak resistance temperature and the polaronic hopping energy is seen which is not simply linear. The low temperature resistivity is seen to be fit better by a model of single magnon scattering, and a near linear correlation between the resistivity due to magnon scattering and static impurities is observed.