Direct Growth of Langasite from the Melt

Even though LGS is an incongruent-melting material, it can grow directly from a pseudocongruent melt via the Czochralsld method using a LGS seed crystal when the appropriate supercooling is provided. 

LS lanthanum silicate. Chemical formulae or abbreviations denote the primary phase volumes. The thick arrow shows the stoichiometric composition of langasite. (Reproduced by the permission of Elsevier Ltd.) 

and thus, it is difficultfor LS(G) to crystallize on the LGS seed. On the other hand, the supercooling necessary for the growth of LGS, AT p is smaller than the actual supercooling in the system for LGS, and thus, it is possible 

Optimal Composition for the Growth of Langasite via the Czochraiski Method [21] 

The optimal melt composition for direct growth of LGS from the melt was studied by investigating the solid-solution region of LGS and the compositional shift of crystals as well as residual melt during growth. The optimal composition could be addressed as a pseudocongruent-melting composition. 

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