Ferromagnetism in Ge1−xCrxTe epilayers grown by molecular beam epitaxy

Abstract

IV-VI ferromagnetic semiconductor Ge1−xCrxTe has been grown on BaF2 (111) by molecular beam epitaxy. The ferromagnetism was clearly established by direct magnetization and Hall measurements. The experimental correlation between the anomalous Hall resistivity ρxy and the resistivity ρxx, ρxy∝ρxx1.76, is understood from the semiclassical nature of the charge carrier dynamics, suggesting that the ferromagnetism gives rise to p-d exchange interaction. The Curie temperature increases systematically from the substrate temperature TS of 300to250to200°C and with increasing the Cr composition along with each TS.