Chemically-Deposited Thin Ferrite Films

Thin ferrite and garnet films have been prepared by chemically depositing stoichiometric ratios of alcoholic solutions of metal nitrates with divalent and trivalent cations onto ceramic substrates which were then subjected to a firing cycle to form the desired film composition. An experimental 35-Gc/s resonance isolator was made using single or multilayered nickel, zinc, and magnesium films as the nonreciprocal element. A reverse-to-forward loss ratio in excess of 100) to 1 with less than 1 dB insertion loss was attained. The use of these films was also found to have superior isolation properties over slabs cut from bulk materials when deposited onto the active rutile maser crystal in a millimeter travling-wave maser. Crystallographic and ferrimagnetic resonance parameters were also studied, and it was found that at least 90 percent of major phase structure was obtained for each film, and their ferrimagnetic linewidths, measured at X-band, ranged between 125 and 1000 oersteds.