Blocky and spheroidal growth in Y_(1.5)Ba_2Cu_3O_x system

摘要

Solidification of Y_(1.5)Ba_2Cu_3O_x system was studied with the aim to find the temperature of self-nucleation. The microstructure after cooling from isothermal dwells in the temperature range 984-995 ℃ was analysed. It is shown that blocky YBa_2Cu_3O_(7-δ) crystals were self-nucleated and grown during isothermal dwells below 988 ℃ and spheroidal multicrystals were formed during cooling from isothermal dwells at higher temperatures. The symmetrical and radial YBa_2Cu_3O_(7-δ) crystal branches of spheroids grow in the <110> crystal direction.