XRD patterns of Ta/Nd(x nm)/NdFeB (600 nm)/Nd(x nm)/Ta films annealed for 30 min with (a) x = 250, at 923 K, (b) x = 250, at 1023 K, (c) x = 1000, at 923 K, (d) x = 1000, at 1023 K.