Coercive Field and Magnetization Deficit in Ga(1-x)Mn(x)As Epilayers

TL;DR

This study investigates the magnetization behavior and coercive field in Ga(1-x)Mn(x)As epilayers, revealing a magnetization deficit and concentration-dependent coercivity, providing insights into the magnetic properties of diluted magnetic semiconductors.

Contribution

It presents experimental measurements of magnetization and coercive field in Ga(1-x)Mn(x)As, highlighting the spin state separation and validating theoretical predictions about coercivity dependence on Mn concentration.

Findings

Magnetization deficit below saturation suggests non-ferromagnetic Mn spins are energetically separated.

Coercive field decreases with increasing Mn concentration, consistent with theory.

Low temperature magnetization measurements up to 3 T reveal significant magnetic behavior insights.

Abstract

We have studied the field dependence of the magnetization in epilayers of the diluted magnetic semiconductor Ga(1-x)Mn(x)As for 0.0135 < x < 0.083. Measurements of the low temperature magnetization in fields up to 3 T show a significant deficit in the total moment below that expected for full saturation of all the Mn spins. These results suggest that the spin state of the non-ferromagnetic Mn spins is energetically well separated from the ferromagnetism of the bulk of the spins. We have also studied the coercive field (Hc) as a function of temperature and Mn concentration, finding that Hc decreases with increasing Mn concentration as predicted theoretically.