Pr_(0.2)Yb_(0.8-x)La_xBa_2Cu_3O_(7-δ)体系的超导电性和磁性

本文研究了Pr_(0.2)Yb_(0.8-x)La_xBa_2Cu_3O_(7-δ)体系的晶体结构,超导电性和磁性。结果表明,在Pr含量不变的条件下,超导转变温度随稀土离子半径增大而降低,当x≈0.65时,Tc=0;电子比热和费密能级上的态密度也随稀土离子半径增大而降低。并讨论了稀土离子半径与杂化的关系。     

INFLUENCE OF RELATIVE DENSITY AND PARTICLE SIZE ON THE SPECIFIC HEAT OF NANOCRYSTALLINE IRON

The specific heats of two nanocrystalline iron samples with different structures have been measured in the temperature range from 2 to 26 K. Experimental results show that the specific heat of nanocrystalline iron samples exhibits abnormal characteristic compared with that of standard bulk iron. The contributions of quantum size effect, surface mode and Einstein mode have been observed in the measurement. Through analyses, it is discovered that the relative density and particle size have a great influence on specific heat of nanocrystalline iron at low temperature.     

Pr0.2Yb0.8-xLaxBa2Cu3O7-δ体系的超导电性和磁性

本文研究了Pr_0.2Yb_0.8-xLa_xBa₂Cu₃O_7-δ体系的晶体结构,超导电性和磁性。结果表明,在Pr含量不变的条件下,超导转变温度随稀土离子半径增大而降低,当x≈0.65时,T_c=0;电子比热和费密能级上的态密度也随稀土离子半径增大而降低。并讨论了稀土离子半径与杂化的关系。 关键词：