in phase diagram with a miscibility gap, a phase transition in a solid solution α, which decomposes upon cooling into isomorphous solid solution α1 and α2 (see: phase transition; compare: decomposition), faasiüleminek faasidiagrammil, mis seisneb jahtumisel tardfaasi α lagunemises isomorfseteks tardfaasideks α1 ja α2 (vt faasiüleminek; vrd lagunemine)
