Direct crystallization of Y3Fe5O12 garnet by containerless solidification processing

Yttrium-iron garnet, Y3Fe5O12 (YIG), is formed via the peritectic reaction of YFeO3 (YIP) and liquid phases. The direct growth of YIG from a highly un dercooled melt with stoichiometric YIG composition was studied using an aer o-acoustic levitator with a CO2 laser heating system. Although a YIG drople t was successfully levitated and undercooled to 1327 degreesC, about 250 de greesC below its peritectic temperature (Tp), YIP was primarily solidified in the microstructure of dendritic YIP with interdendritic eutectics of YIP and FeOx. However, when a droplet was quenched after it was undercooled be low Tp, single phase of YIG without YIP and FeOx was found. The X-ray diffr action pattern as well as microstructure indicated that YIG was solidified directly and congruently from the undercooled melt, bypassing the peritecti c reaction.