薄膜磁気ヘッド用Ni-Znフェライトの組織制御

Abstract

In this experiment, the microstructural changes during sintering of Ni-Zn ferrites used as the substrate for magnetic recording heads of thin films have been studied by SEM, XRD and XPS. The results obtained are sammarized as follows.(1) No precipitates were recognized on the specimen furnace-cooled from 1423 K during sintering in air. ZnO precipitates, however, were observed at the grain boundary, especially at the triple point of the specimen furnace-cooled from 1453 K. These precipitates have been elongated along grain boundaries of the specimen furnace-cooled from 1453 K after holding at this temperature for 10.8 ks.(2) While the above mentioned ZnO precipitates were not observed on the specimen sintered in O2 atmosphere, the grain coarsening was observed and the residual pores were also recognized inside the grain.(3) The existence of Ni3+ ion was detected by XPS on the specimen prepared by HIP process at 1373 K for 18 ks under 120 MPa after sintering in air at 1453 K for 10.8 ks, where the ratio of Ni3+/(Ni2++Ni3+) was confirmed to be 3%.