A multichannel superconducting tunnel junction detector for high-resolution X-ray spectroscopy of magnesium diboride films
| Autor: | Stephan Friedrich, S.E. Labov, O. Drury, Eun-Mi Choi, Sung-Ik Lee, Changyoung Kim, Tobias Funk, Arturas Vailionis, Hyeong-Jin Kim, Won Nam Kang, Stephen P. Cramer, T. Niedermayr |
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| Rok vydání: | 2003 |
| Předmět: |
X-ray spectroscopy
High-temperature superconductivity Materials science Condensed matter physics Absorption spectroscopy Condensed Matter Physics Electronic Optical and Magnetic Materials law.invention chemistry.chemical_compound chemistry law Tunnel junction Magnesium diboride Superconducting tunnel junction Electrical and Electronic Engineering Atomic physics Anisotropy Spectroscopy |
| Zdroj: | IEEE Transactions on Appiled Superconductivity. 13:1114-1119 |
| ISSN: | 1051-8223 |
| Popis: | We have built a high-resolution soft X-ray spectrometer using a 3 /spl times/ 3 array of superconducting Nb-Al-AlO/sub x/-Al-Nb tunnel junctions. The detector is cooled to /spl sim/0.1 K by a two-stage adiabatic demagnetization refrigerator while being held at the end of a 40-cm-long detector snout that can be inserted into an experimental chamber. The 0.6 mm /spl times/ 0.6 mm array has an energy resolution of 10-15 eV FWHM for X-ray energies below 1 keV and total count rate capabilities above 100 000 counts/s. We demonstrate the capabilities of the instrument in a study of anisotropy in c-axis oriented MgB/sub 2/ films by near edge X-ray absorption spectroscopy. The absorption fine structure at the B K-edge differs for excitation with X-rays polarized along the c-axis and in the ab-plane of the MgB/sub 2/ film. We discuss the implications of the anisotropy for the density of states in MgB/sub 2/ at the Fermi surface. |
| Databáze: | OpenAIRE |
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