【摘要】 通过对高掺杂Sn的YBa₂Cu_3-xSn_XO_7-y体系的穆斯堡尔谱测量,确定了掺杂的Sn全部以Sn⁴⁺离子形式存在,多数占据Ba,Y,Cu（2）,少量占据Cu（1）位置,Sn含量x不同,其在各个位置上的占有比例也不同,超导电性测量表明,该系列样品T_c大都在77K以上,Cu（2）和Y位上的金属离子被替代对超导温度T_c影响不大,为Cu-O面不是超导的主要原因提供了证据。更多还原

【Abstract】 Mossbauer measurements of YBa2Cu3-xSnxO7-y compounds with high Sn concentrations have revealed that the Sn dopants all exist as Sn4+, with their majority occupying Ba, Y, Cu(2) sites, and only a small part at Cu(l) sites. The amount of Sn at each site varies with Sn content (x). As for superconductivity, the sample systems are all with Tc above 77 K, this indicates that the substitutions for the metal ions on Cu(2) and Y sites have small effect on Tc, which strongly supports the concept that Cu-O plane does not predominate the superconductivity.更多还原