Influence of temperature, magnetic field, and high hydrostatic pressure on the resistivity and magnetoresistance in La0.9Mn1.1O3±δ ceramics and laser-deposited films

Abstract

The influence of the magnetic field strength (H=0, 2, 4, 6, 8 kOe), high hydrostatic pressures (P=0−1.8 GPa), and temperature (T=77−300 K) on the resistivity ρ, magnetoresistance (ΔR/R0), and phase transition temperatures in ceramic and thin-film samples of the lanthanum manganite La0.9Mn1.1O3±δ is investigated by x-ray-diffraction, magnetic, and resistive methods. It is found that with increasing H and P the resistivity decreases and the temperatures Tms of the metal-semiconductor phase transition and Tp of the magnetoresistance peak increase. The differences in the resistivities, magnetoresistances, and phase transition temperatures in the ceramics and laser-deposited films are explained by their different nonstoichiometry and defect density. The observed linear dependence of ρ and Tms on P suggests that lanthanum manganite ceramics and films could be used as pressure and temperature sensors.