Blocky and spheroidal growth in Y1.5Ba2Cu3Ox system

Abstract Solidification of Y 1.5 Ba 2 Cu 3 O 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 °C was analysed. It is shown that blocky YBa 2 Cu 3 O 7−δ crystals were self-nucleated and grown during isothermal dwells below 988 °C and spheroidal multicrystals were formed during cooling from isothermal dwells at higher temperatures. The symmetrical and radial YBa 2 Cu 3 O 7−δ crystal branches of spheroids grow in the 〈110〉 crystal direction.