高压高温处理对YNi2B2C晶界效应的影响

摘要

Near critical temperature a negative peak in the field-cooled measured-upon-warming magneization curve was observed in YNi2B2C supercon ductor,which was prepared by melting in an arc furnace then treated under high p ressure.The studt of effect of high-temperature and high-pressure treatment on the magnetization curves of bulk and powder samples measured at zero-field coo led and field cooled conditions shows that the negative magnetic peak in the fie ld cooled magnetization comes from the grain boundary that leads a week link,but not from magnetic phase transition or the coexistence of superconductivity and magnetism.The result also demonstrates that the preparation and crystal growth o f the material can be taken under high temperature and high pressere.%在测量经压力处理的氩弧熔炼的YNi2B2C的金属间化合物超导体中场冷磁化率时，观察到升温磁化率曲线在临界温度附近有一个负的磁化率峰。通过研究高压高温处理对粉末样品和块状样品的场冷和零场冷却磁化率曲线的影响，认为场冷时反常负磁化率峰是由于样品中晶界的存在，从而导致晶粒间的弱连接所引起的，而不是由磁相变或超导和磁性共存现象所引起的。并认为有可能利用高压高温技术制备这类化合物和生长单晶。