Magnetic and electrical characteristics of MnAs films grown by metalorganic chemical vapour deposition

Abstract The magnetic and electrical property of changes associated with the phase transition in MnAs have been measured in uncracked material by using thin films grown on to sapphire substrates by metal organic chemical vapour deposition. The films exhibited a first-order transition with Curie points in the range 35–47±1°C. An increase of approximately 60% in the electrical resistivity of the films was measured on heating through the phase transition. The Curie temperature of the films increased with an applied magnetic field by approximately 1.2°C in a field of 600 kA m −1 . This shift in Curie temperature with applied magnetic field also produced a magnetoresistance effect with a maximum value of 2.24% at 600 kA m −1 . The values of these parameters are shown to be dependent upon the growth conditions of the films.