Possible origin of the resistivity anomaly near 235 K in Hg based compounds prepared under high pressure
✍ Scribed by Y.S. Yao; J.W. Li; W.J. Ma; Y.J. Su; B. Ying; W.J. Zhu; S.L. Jia; Y. Yiang; T.C. Zhang; G.T. Zhou; G.H. Cao; Z.X. Zhao
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 527 KB
- Volume
- 234
- Category
- Article
- ISSN
- 0921-4534
No coin nor oath required. For personal study only.
✦ Synopsis
A significant drop of the resistance around 235 K was observed in our experiment on mercury-based samples synthesized under high pressure and high temperature. The drop of the resistance always appeared in samples containing tiny mercury droplets or Hg-Au alloys; it was sometimes also observed in samples with grains of Hg-1223 and grain boundaries containing an excess of Hg compared with the composition ratio of the superconducting phase of Hg-12 (n -1) n. The measurements of DC magnetic susceptibility by a SQUID magnetometer did not demonstrate any diamagnetic behavior around 235 K although a very small drop in the AC magnetic susceptibility was observed at this temperature with a Lakeshore magnetometer. The paper will discuss if the drop in the resistance for the mercury-based compounds at 235 K is due to superconductivity; we rather believe that it is due to the presence of liquid mercury or its alloys in the sample.