论文部分内容阅读
通过采用机械合金化方法制备的高活性的粉体,可以高度可重复性地制备高质量的铁基超导材料Sm0.85Nd0.15FeAsO0.85F0.15.样品具有高临界温度Tc(约51 K)和高临界场Hc2(达到377 T).由WHH公式确定的Hc2显著高于常规固相方法制备样品的典型值(<200 T).高的临界磁场Hc2与样品微结构有很大关系.机械合金化处理的原始粉体包含大量的晶格畸变缺陷,在快速升温和低温退火制备的小晶粒陶瓷样品中这些缺陷会部分残留,因此形成有效的磁通钉扎,从而提高样品的临界场.
The high-quality Fe-based superconducting material Sm0.85Nd0.15FeAsO0.85F0.15 can be prepared with high reproducibility by using high activity powder prepared by mechanical alloying method.The samples have high critical temperature Tc (about 51 K) And Hc2 (up to 377 T) at the upper critical field.The Hc2 determined by the WHH formula is significantly higher than the typical sample prepared by the conventional solid-state method (<200 T) .High critical field Hc2 is strongly related to the microstructure of the sample. The alloyed primary powders contain a large number of lattice distortion defects that may partially remain in the small-grained ceramic samples prepared by rapid heating and low temperature annealing, thus forming an effective flux pinning that increases the critical field of the sample .