Andreev-reflection study of superconducting RNi(2)B(2)C compounds
UNSPECIFIED (1996) Andreev-reflection study of superconducting RNi(2)B(2)C compounds. In: 2nd International Conference on Point-contact Spectroscopy, JUN 07-10, 1995, NIJMEGEN, NETHERLANDS.Full text not available from this repository.
A comparative study has been made of the current-voltage characteristics of RNi(2)B(2)C-Ag point contacts with R = Y, Er, and Ho, at various temperatures and magnetic fields. At low temperatures the double-minimum structure in the differential resistance dV/dI, characteristic for Andreev-reflection processes, can be well described by the Blonder-Tinkham-Klapwijk (BTK) model, yielding an energy gap Delta = 2.42 +/- 0.07, 1.7 +/- 0.2, and 1.04 +/- 0.06 meV for, respectively, the Y-, Er-, and He-based compounds. For the Y- and Er-based compounds, the temperature dependence of the spectra is in quantitative agreement with the BTK prediction. However for the He-based compound, an anomalous temperature dependence with two superconducting transitions at 8.5 and 6.5K has been observed. The ratio 2 Delta/k(B)T(c) amounts about 3.7 for all compounds (providing one takes T-c* similar or equal to 6.5K for the critical temperature of the Ho compound), corresponding to a moderate electron-phonon coupling strength.
|Item Type:||Conference Item (UNSPECIFIED)|
|Subjects:||Q Science > QC Physics|
|Journal or Publication Title:||PHYSICA B|
|Publisher:||ELSEVIER SCIENCE BV|
|Number of Pages:||4|
|Page Range:||pp. 189-192|
|Title of Event:||2nd International Conference on Point-contact Spectroscopy|
|Location of Event:||NIJMEGEN, NETHERLANDS|
|Date(s) of Event:||JUN 07-10, 1995|
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