Magnetic and magneto-optical properties of MnSb films on various substrates

Magnetic and magneto-optical properties of MnSb films with different crystalline orientations on various semiconductors of GaAs(100), GaAs(111)A, B, and sapphire(0001) have been measured by a vibrating sample magnetometer (VSM) and a home-made magneto-optical Kerr effect (MOKE) system. All these samples have their easy axes in the plane and show ferromagnetic properties. Among these samples, the film on GaAs(111)B has the lowest coercive force H, and the largest squareness (SQ) value, whereas the film on GaAs(100) shows the largest H-c and the lowest SQ value. A large Kerr rotation angle of about 0.3 degrees was observed at a wavelength of lambda = 632.8 nm for the film on sapphire in the field applied both parallel and perpendicular to the film plane. However, the MnSn films on other substrates do not have an observable Kerr rotation. The dynamic effect of the hysteresis was also measured using our MOKE system. As the frequency of applied magnetic field increases, the loop rounds off at the corners and the loop area increases. (C) 1999 Elsevier Science B.V. All rights reserved.