Spin polarisation and non-isotropic effective mass in the conduction band of GdN

GdN is a ferromagnetic semiconductor which has seen increasing interest in the preceding decades particularly in the areas of spin- and superconducting- based electronics. Here we report a detailed computational and optical spectroscopy study of the electronic structure of stoichiometric and nitrogen vacancy doped GdN. Based on our calculations we provide the effective mass tensor for undoped GdN, and some indicative values for electron doped GdN. Such a property is valuable as it can affect device design, and can be measured experimentally to validate the existing computation results.