Residual stress optimization in FeAlN pole materials

RF-diode reactively sputtered FeAIN films, which are good candidates for hi gh-density write head pole materials, usually have very Large compressive r esidual stresses. In this paper we describe our efforts to lower the residu al stress, and study the effects of lowered stress on the magnetic properti es of the FeAIN films, It is found that increasing the total sputtering pre ssure while keeping the optimum Fe to N arrival flux ratio constant can low er the residual stress. The films with lowered residual stress, however, ar e more susceptible to the formation of stripe domains, which are detrimenta l to the magnetic properties. In order to avoid these stripe domains, the t hickness of the film should not exceed the critical stripe domain onset thi ckness. For applications where thicker films are desired, we demonstrate th at Laminating single layer films whose thicknesses do not exceed the critic al thickness produces films with good magnetic properties and acceptable re sidual stress.