Magnetoresistance Relaxation in (La0.5Eu0.5)0.7Pb0.3MnO3 Single Crystals under the Action of a Pulse Magnetic Field

TL;DR

This study investigates how magnetoresistance in (La0.5Eu0.5)0.7Pb0.3MnO3 single crystals relaxes after exposure to a pulse magnetic field, revealing a relaxation time of about 1 millisecond and its relation to phase boundaries.

Contribution

It introduces a new understanding of magnetoresistance relaxation mechanisms related to phase boundaries in substituted lanthanum manganite crystals.

Findings

Relaxation time is approximately 10^-3 seconds.

Relaxation parameter correlates with electrical resistance temperature dependence.

Relaxation reflects the number of phase boundaries, not phase ratios.

Abstract

Magnetoresistance of substituted lanthanum manganite (La0.5Eu0.5)0.7Pb0.3MnO3 in the pulse magnetic field H = 25 T was measured at different temperatures. Magnetoresistance relaxation with a characteristic time of 10 -3 s was found. It has been established that the temperature dependence of the relaxation parameter {\tau}(t) at different temperatures correlates with the temperature dependence of electrical resistance R(T). The proposed relaxation mechanism is related to relaxation of conducting and dielectric phases in the sample volume under phase stratification conditions. It is shown that relaxation parameter {\tau} reflects the number of boundaries in the volume and not the ratio between phase fractions.