Evidence of metallic clustering in annealed Ga1-xMnxAs from atypical scaling behavior of the anomalous Hall coefficient

TL;DR

This study investigates the anomalous Hall effect in annealed Ga1-xMnxAs, revealing atypical scaling behavior linked to metallic clustering, which enhances understanding of inhomogeneous magnetic semiconductors.

Contribution

It demonstrates that atypical scaling of the anomalous Hall coefficient indicates metallic clustering in annealed Ga1-xMnxAs, supported by optical spectroscopy evidence.

Findings

Scaling parameter n varies with annealing temperature.

Atypical n > 3 behavior suggests metallic inclusions.

Optical spectroscopy confirms metallic clustering.

Abstract

We report on the anomalous Hall coefficient and longitudinal resistivity scaling relationships on a series of annealed Ga1-xMnxAs epilayers (x~0.055). As-grown samples exhibit scaling parameter n of ~ 1. Near the optimal annealing temperature, we find n ~ 2 to be consistent with recent theories on the intrinsic origins of anomalous Hall Effect in Ga1-xMnxAs. For annealing temperatures far above the optimum, we note n > 3, similar behavior to certain inhomogeneous systems. This observation of atypical behavior agrees well with characteristic features attributable to spherical resonance from metallic inclusions from optical spectroscopy measurements.