Phase selection in the undercooled peritectic Y3Fe5O12 melt
Phase selection in the undercooled peritectic Y3Fe5O12 melt
复制标题
过冷包晶 Y3Fe5O12 熔体的相选择
DOI：
10.1016/s1359-6454(02)00043-5
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发表时间：
2002
期刊：
影响因子：
9.4
通讯作者：
K. Kuribayashi
中科院分区：
文献类型：
--
作者：
K. Nagashio;K. Kuribayashi
利用气动声学悬浮器研究了Y3Fe5O12石榴石（YIG）的无容器凝固过程，研究了过冷熔体中YIG的直接生长。虽然熔体过冷低于周晶温度（Tp），YFeO3钙钛矿（YIP）主要固化在自发形核的标本。基于竞争生长的相选择理论表明，即使熔体过冷度远低于Tp，YIG也不会直接从过冷熔体中凝固。然而，当熔体过冷低于Tp下降到具有高导热率的铜冷却板上时，YIG作为主相在冷却板周围凝固。另一方面，对于过冷熔体滴在具有低导热系数的石英玻璃激冷板上，YIP主要凝固。这些结果表明，由铜冷却板实现的高冷却速率阻止了YIP的形核，并导致YIG的直接生长，这是由基于竞争形核速率的相选择来解释的。
Containerless solidification of peritectic Y3Fe5O12garnet (YIG) was examined using an aero-acoustic levitator to investigate the direct growth of YIG from the undercooled melt. Although the melt was undercooled below the peritectic temperature (Tp), YFeO3perovskite (YIP) was primarily solidified in the spontaneously nucleated specimen. The phase selection theory based on the competitive growth indicates that YIG never solidifies directly from the undercooled melt even when the melt is undercooled much below Tp. However, when the melt undercooled below Tpwas dropped onto the copper chill plate with high thermal conductivity, YIG solidified around the chill plate as a primary phase. On the other hand, for the undercooled melt dropped onto the quartz glass chill plate with low thermal conductivity, YIP primarily solidified. These results suggest that the high cooling rate achieved by the copper chill plate prevented the nucleation of YIP and led to the direct growth of YIG, which is explained by the phase selection based on the competitive nucleation rate.