熔融织构(MTG)的YBa_2Cu_3O_(7-δ)块材的交流磁化率研究

AC Susceptibility on YBa_2Cu_3O(7-δ) Bulk Material by Melt-textured Growth Method

本文通过控制温度梯度和降温速率等烧结工艺制备了熔融织构的YBa_2Cu_3O_(7-8)块材,经结构分析和交流磁化率测量,发现样品晶粒择优取向,样品开始出现抗磁信号的温度为92K,交流磁化率虚部只存在一个反映晶粒内部损耗的小尖峰。施加直流场0-600高斯,小尖峰向低温移动,峰的半宽度略有展宽,峰的高度增强。用磁滞损耗解释了上述结果。

By controling the temperature gradient and the slow cooling rate, we have preparedYBa_2Cu_3O_(7-б) bulk material by melt-texted growth (MTG) method. Structure analysisand ac. susceptibility measurement show that the crystal is preferentially aligned and thetemperature is about 92K while the onset demagnetic signal appears. only one singlepeak of x” appears which shows intragrain loss. The small peak moves to low tempera-ture, the half-width of the peak widen a little, and the peak becomes stronger when dc.external field varies from 0 to 600 guass, We explained the experimental results by themagnetic hysteresis loss.