Effects Of Pulling Speed And Hot Zone Temperature On The Directional Growth Of YBa2Cu3Ox Superconductor

Abstract

The effects of pulling speed and hot zone temperature on the microstructure and the superconducting properties of YBa2Cu3Ox sample textured using directional growth of Y2BaCuO5, BaCuO2, and CuO powder mixture were studied. The grain size, the alignment, and the critical current density of the sample were increased as the pulling speed decreased. The sample grown directionally at 1.5 mm h(-1) pulling speed consisted of a single grain. The zero resistivity temperture and the critical current density of the sample increased as the hot zone temperature increased up to 1120 degrees C beyond which the sample consisted of Y2O3 and impurities and showed resistivity at 77 K. The sample grown directionally at 1.5 mm h(-1) pulling speed and at 1120 degrees C hot zone temperature showed sharp resistivity transition of 91 K zero resistivity and over 6000 A cm(-2). The sample showed well aligned microstructure. Compared to data from another study, the hot zone temperature required to produce maximum critical current density is lower due to low liquid forming temperature.