Crossover critical behavior of Ga1-xMnxAs

TL;DR

This study investigates the critical magnetic behavior of Ga1-xMnxAs near its Curie temperature, revealing a crossover from mean-field to Ising-like behavior and determining key physical parameters.

Contribution

It provides the first experimental evidence of crossover critical behavior in Ga1-xMnxAs using thermal diffusivity measurements.

Findings

Observed crossover from mean-field to Ising-like critical behavior.

Determined the Ginzburg number and exchange interaction length.

Measured the critical exponent α for different samples.

Abstract

The critical behavior of Ga1-xMnxAs in a close vicinity of the Curie temperature was experimentally studied by using the thermal diffusivity measurements. Taking into account that the inverse of the thermal diffusivity has the same critical behavior as the specific heat, the critical exponent {\alpha} for the samples investigated has been determined. With approaching close to the critical temperature, the crossover from the mean-field-like to the Ising-like critical behavior has been observed. From the crossover behavior the values of the Ginzburg number and the exchange interaction length in Ga1-xMnxAs with different concentrations of Mn were determined.