Magnetization of ultrathin (Ga,Mn)As layers

Abstract

Kerr rotation and Superconducting QUantum Interference Device (SQUID) magnetometry measurements were performed on ultrathin (Ga${}_{0.95}$Mn${}_{0.05}$)As layers. The thinner layers (below 250 Å) exhibit magnetic properties different than those of thicker ones, associated with different microstructure, and some degree of inhomogeneity. The temperature dependence of the field-cooled-magnetization of the layers is recorded after successive low temperature annealings. While the Curie temperature of the thicker layer (250 Å) is nearly unchanged, the critical temperature of the thinner layers is enhanced by more than 23 K after two annealings. Secondary Ion Mass Spectrometry (SIMS) experiments on similar layers show that Mn is displaced upon annealing. The results are discussed considering a possible segregation of substitutional and interstitial Mn atoms at the surface of the (Ga,Mn)As layers.

REVTeX 4 style; 5 pages, 4 figures; revised 25/2; revised 25/7 and accepted for publication

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Cited by in corpus (4)

• Influence of defects on the lattice constant of GaMnAs
• Influence of annealing parameters on the ferromagnetic properties of optimally passivated (Ga,Mn)As epilayers
• Spontaneous magnetization in presence of nanoscale inhomogeneities in diluted magnetic systems
• Possible magnetic-field-induced voltage and thermopower in diluted magnetic semiconductors