Electrical and magnetic properties of GaN codoped with Eu and Si

Abstract

GaN thin films codoped with Eu and Si were grown on sapphire by solid source molecular beam epitaxy technique. Si incorporation changed GaN:Eu thin films from highly resistive to n-type conductive but not to levels normally achieved in conventional Si-doped GaN films. The magnetic properties of the codoped GaN films were measured by an alternating gradient magnetometer. While all samples exhibited hysteresis behavior at room temperature, there was a marked dependence on the Si codoping. At low-to-moderate Si doping levels, an increase up to approximately nine times in saturation magnetization was observed for films having higher conductivity, which also displayed an anomalous Hall effect. Under illumination at 371 nm, an increase in saturation magnetization was observed for all samples.