CORRELATION BETWEEN CRYSTALLINE-STRUCTURE AND SOFT-MAGNETIC PROPERTIES IN SPUTTERED SENDUST FILMS

We have investigated the change in crystallographic and magnetic prope rties of sendust thin films before/after annealing. Films were deposit ed by both rf diode and rf magnetron sputtering. rf diode-sputtered fi lms did not possess soft magnetic properties in the as-deposited state . Films were subsequently annealed in both a conventional oven and a r apid thermal annealing (RTA) system. The coercivity of the films decre ased from over 10 Oe to a minimum value of 0.6 Oe after annealing and a systematic shift in the (110) x-ray diffraction (XRD) peak position towards that of bulk sendust was observed. No additional XRD peaks wer e observed after annealing. The optimum annealing conditions to minimi ze coercivity was found to be 1-2 h at 550 degrees C. By comparison, f ilms processed by RTA resulted in minimum coercivity of 0.9 Oe obtaine d after annealing for 2 min at 550 degrees C. XRD for films annealed b y both RTA and oven annealing showed a similar decrease in the d spaci ng of the (110) plane, indicating a release of tensile strain in the f ilms that had been introduced during deposition. rf magnetron-deposite d samples possessed coercivities as low as 1.4 Oe as deposited and sho wed in-plane anisotropy. XRD again showed a (110) texture, however, th e peak intensity of magnetron-sputtered samples was a factor of 20 les s than the diode-sputtered films of the same thickness. The position o f the (110) peak, however, was close to that of rf diode deposited fil ms after annealing indicating that the magnetron-sputtered films were relatively stress-free. (C) 1997 American Institute of Physics.