钙钍掺杂YBCO超导体中的载流子浓度

Carrier Density in YBCO Superconductors Doped by Ca and Th

测量了钙钍掺杂的多晶ＹＢＣＯ超导体的低温霍尔系数ＲＨ、霍尔电阻率ρＨ及其随温度Ｔ变化的特性。结果表明，在该掺杂系统中，ＲＨ大体上正比于Ｔ－１。推算并分析了霍尔载流子浓度ｎＨ，发现以掺杂Ｃａ、Ｔｈ来取代Ｙ时，超导转变温度Ｔｃ、霍尔浓度ｎＨ及温度变化率ｄｎＨ／ｄＴ都随掺杂浓度ｘ的增加而降低。

The Hall coefficients and longitudinal resistivity of (Ca,Th) doped YBCO superconductors were measured in the normal state. The values of Hall density n H and slope d n H/d T were also estimated. It was found that suppressed T c, Hall number n H and the slope d n H/d T , are proportionally decreasing with the increment of the doped density, when the dopants(Ca, Th) substitute for Y.