Film synthesis of Y3Al5O12 and Y3Fe5O12 by the spray-inductively coupled plasma technique

Thin films of yttrium aluminum garnet (YAG, Y3Al5O12) and yttrium iron garnet (YIG, Y3Fe5O12) were synthesized on single-crystal Al2O3 substrates by a modification of spray pyrolysis using a high-temperature inductively coupled plasma at atmospheric pressure (spray-ICP technique). Using this technique, films could be grown at faster rates (0.12 mum/min for YAG and 0.10 mum/min for YIG) than using chemical vapor deposition (0.005-0.008 mum/min for YAG) or sputtering (0.003-0.005 mum/min for YIG). The films were dense and revealed a preferred orientation of (211). The growth of YIG was accompanied by coprecipitation of alpha -Fe2O3. The coprecipitation, however, could be largely suppressed by preliminary formation of a Y2O3 layer on the substrate.