INVESTIGATION OF EMPIRICAL LAWS FOR SUPERCONDUCTIVITY OF ALLOY AND COMPOUND SUPERCONDUCTORS
Liu Long-jian (刘隆鉴)a, Zhang Zhuang-jian (章壮健)b
a Laboratory Center of Physics, Sichuan Institute of Technology, Chengdu 610039, China; b Department of Materials Science, Fudan University, Shanghai 200433, China
Abstract By studying the average effect of the electronegativity of alloy and compound superconductors, some empirical laws are found. The average value of the electronegativity of alloy superconductors $\overline{\chi}$ is from 1.3 to 1.9, most of which is concentrated in the region $1.5<\overline{\chi}<1.8$. The $\overline{\chi}$ of many higher Tc superconductors is nearly 1.60. All these characteristics are similar to element superconductors. The average value of the electronegativity $\overline{\eta}$ of positive valence elements in oxide superconductors is from 1.3 to 1.6, and the average effect of an electronegativity of zero on every element $\overline{\zeta}$ is from 1.75 to 2.00. The mean of $\overline{\eta}$ and $\overline{\zeta}$ is from 1.5 to 1.8. When both $\overline{\eta}$ and $\overline{\zeta}$ are near the limit value (1.3 or 1.6 and 1.75 or 2.00), the material has a very low Tc, even is non-superconductive. The $\overline{\eta}$ of other compound superconductors is either too high or too low, and the $\overline{\zeta}$ is too low so that the Tc of these superconductors is quite low. Studying the average effect of the electronegativity of non-superconducting compounds further confirms the laws.
Received: 18 March 2001
Revised: 20 May 2001
Accepted manuscript online:
PACS:
74.70.Ad
(Metals; alloys and binary compounds)
Fund: Project supported by the Foundation from the Education Commission of Sichuan Province, China (Grant No. 199919655).
Cite this article:
Liu Long-jian (刘隆鉴), Zhang Zhuang-jian (章壮健) INVESTIGATION OF EMPIRICAL LAWS FOR SUPERCONDUCTIVITY OF ALLOY AND COMPOUND SUPERCONDUCTORS 2001 Chinese Physics 10 847
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