Angular dependence of the upper critical field of NbN thin films

The upper critical field H(c2)(T) of NbN has previously been found to be anisotropic in films with both columnar-void and equiaxed-grained microstructures. In this study we have measured the angular dependence of H(c2)(O,0) for several equiaxed-grained samples, where O is measured from the normal to the sample and 0 is in the plane of the sample.