Thin films of CrSb grown by solid-source molecular-beam epitaxy on GaAs, (Al,Ga)Sb, and GaSb are found to exhibit ferromagnetism. Reflection high-energy electron diffraction and high-resolution cross sectional transmission electron microscopy both indicate that the structure is zincblende. Temperature dependence of remanent magnetization shows that the ferromagnetic transition temperature is beyond 400 K.

Fig. 1 Schematic diagrams of the samples grown and measured in the present work. For samples A, B, C, and D, CrSb was grown on GaAs, AlGaSb, GaSb and GaAs buffer layer, respectively. The thickness of CrSb is described in the growth time in seconds. If CrSb keeps zincblende structure, the growth time of 30 seconds corresponds to 1 ML by using typical Cr flux intensity of 2´1013cm-2s-1.

Fig.2  High-resolution cross sectional transmission electron micrograph of 1 ML zincblend CrSb embedded between two  GaAs layers (sample D). Inset shows the image over a wider area.

Fig. 3  Magnetic field dependence of magnetization of CrSb grown on GaAs (sample A, triangles), Al0.84Ga0.16Sb (sample B, circles), and GaSb (sample C, squares), at 300 K under magnetic field parallel to the sample surface. Inset shows the hysteresis loops at around zero magnetic field.

Fig. 4 Temperature dependence of remanent magnetization of CrSb grown on GaAs (sample A, triangles), Al0.84Ga0.16Sb (sample B, circles), and GaSb (sample C, squares), under zero magnetic field. The inset shows the hysteresis loops at around zero magnetic field of sample B at temperatures 10, 20, 30 and 40 K.

Table I. Growth data of zincblende CrSb on GaAs, Al0.84Ga0.16Sb and GaSb buffer layers and their saturationmagnetization.