Post-processing and processing treatment and their effect on structure andproperties of Finemet films

The effect of heating of substrates (75 degreesC, 110 degreesC, 145 degrees C and 180 degreesC), electrical bias (50, 75, 100, 125, 150, 200 and 250 V) on the substrate during preparation of amorphous films, and post-annealing on structure and properties of Finemet films were studied. Films were obta ined by ion-beam sputtering a Fe73.5Si16.5B6Cu1Nb3 alloy. The structural ch anges of films due to different annealing temperatures were studied by mean s of transmission electron microscopy (TEM; Philips CM 300) and X-ray diffr action analyzer (DRON-4). Magnetostatic properties measurements were made w ith the vibrating sample magnetometer (VSM). Annealing after sputtering dec reases the coercive force but its magnitude depends on the preparation cond itions. We found that film deposition onto heated substrates had a critical temperature between 110 degreesC and 145 degreesC, at which the film had c oercivity H-c > 30 Oe. The samples deposited without the bias coercive forc e decreased after annealing. But the bias voltage during sample preparation reduced this effect of annealing. (C) 2001 Published by Elsevier Science B .V.