Constitution of Stable and Metastable Quasi Binary Phase Diagrams for TmFeO 3 -ScFeO 3 System by Undercooling Solidification Using the Containerless Technique

Abstract

Spherical samples of Tm 1 ︲ x Sc x FeO 3 were solidified from the undercooled melt under the containerless state using an aerody - namic levitation （ ADL ） furnace. The change of solidification behavior from double recalescence to single recalescence and powder X ︲ ray diffraction （ XRD ） analysis of as ︲ solidified samples revealed that metastable hexagonal LnFeO 3 （ h ︲ LnFeO 3 ） stabilizes with increasing of mole fraction of Sc. The reason for this stabilization was ascribed to the decrease of the difference in the liquidus temperatures of stable orthorhombic LnFeO 3 （ o ︲ LnFeO 3 ） and metastable h ︲ LnFeO 3 phases. Annealing the as ︲ solidified samples at 1473 K for 1 hour resulted in the two ︲ phase coexistent states of o ︲ LnFeO 3 and garnet （ c ︲ A 3 B 5 O 12 ） at 0 ＜ x ＜ 0 . 3, c ︲ A 3 B 5 O 12 and h ︲ LnFeO 3 at 0 . 3 ＜ x ＜ 0 . 5 , and h ︲ LnFeO 3 and c ︲ ScFeO 3 at 0 . 5 ＜ x ＜ 1 . 0. Based on these results, we proposed the quasi binary phase diagram between TmFeO 3 and ScFeO 3 . ［ doi:10 . 2320 / jinstmet.JAW201707 ］ （ ）