Effect of nitrogen interstitial in α-Fe crystalline on the magnetic soft properties of FeTaN thin films

Abstract

The effect of nitrogen interstitial in α-Fe crystalline on the magnetic soft properties of Fe87.5Ta12.5Nx films has been investigated. The magnetic soft properties can be improved by carefully controlling the nitrogen flow ratio during sputtering and the postannealing to result in a film with fine grain size and low magnetostriction. Using x-ray diffraction technique, the nitrogen content in the α-Fe crystalline of FeTaN film can be estimated from the effect of lattice expansion of α-Fe crystalline due to nitrogen interstitial. It is found that the film with about 7.5 at. % N2 in α-Fe crystalline exhibits the best magnetic soft properties of Br=1.6 T, Hc=0.2 Oe and μi(1 MHz)=3400, respectively. X-ray diffraction analysis is found to provide a proper and an easy way to identify the suitable condition for growing excellent magnetic soft FeTaN thin films.