MAGNETIC-PROPERTIES AND STRUCTURE OF ND-FE-B THIN-FILMS WITH CR AND TI UNDERLAYERS

We investigated the influence of the underlayers of Cr and Ti on the s tructure and magnetic properties of Nd-Fe-B thin films which were prod uced by a conventional RF sputtering method. The thickness of the unde rlayer and the substrate temperature were varied from 0 to 5000 Angstr om and from room temperature to 670 degrees C, respectively. It was fo und that the type and the thickness of the underlayer materials and th e substrate temperature strongly influenced the crystal orientation an d magnetic properties. The main crystalline phase was a Nd2Fe14B compo und, whose tetragonal c-axis was aligned perpendicularly to the film p lane. A high coercive force (H-c = 3.7 kOe) was achieved in the follow ing conditions; Cr underlayer with the thickness of 500 Angstrom and t he substrate temperature of 650 degrees C. (C) 1998 Elsevier Science B .V. All rights reserved.