Optical and magneto-optical properties of single crystalline uranium nitride

We present optical measurements in the range from 1 to 10 eV and magneto-optical measurements from 1 to 5 eV on an UN single crystal. The complex optical conductivity is obtained from ellipsometric spectroscopy. In addition, the polar magneto-optical Kerr effect at high fields near TNTN and the off-diagonal elements σ˜xy of the optical conductivity have been determined. The spectra have been fitted with a Drude–Lorentz model. Comparing our results with those for heavier uranium monopnictides, we find that the excitations have similar energies but that σ˜xy is smaller than in the heavier monopnictides.