The impact of heavy Ga doping on superconductivity in germanium
Vernadsky National Library of Ukraine
Переглянути архів Інформація| Поле | Співвідношення | |
| Title |
The impact of heavy Ga doping on superconductivity in germanium
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| Creator |
Skrotzki, R.
Herrmannsdörfer, T. Heera, V. Fiedler, J. Mücklich, A. Helm, M. Wosnitza, J. |
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| Subject |
Сверхпроводимость и сверхтекучесть
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| Description |
We report new experimental results on how superconductivity in gallium-doped germanium (Ge:Ga) is influenced by hole concentration and microstructure. Ion implantation and subsequent flash-lamp annealing at various temperatures have been utilized to prepare highly p-doped thin films consisting of nanocrystalline and epitaxially grown sublayers with Ga-peak concentrations of up to 8 at.%. Successive structural investigations were carried out by means of Rutherford-backscattering spectrometry in combination with ion channelling, secondaryion-mass spectrometry, and high-resolution cross-sectional transmission electron microscopy. Hole densities of 1.8·10²⁰ to 5.3·10²⁰ cm⁻³ (0.4 to 1.2 at.%) were estimated via Hall-effect measurements revealing that only a fraction of the incorporated gallium has been activated electrically to generate free charge carriers. The coincidence of a sufficiently high hole and Ga concentration is required for the formation of a superconducting condensate. Our data reflect a critical hole concentration of around 0.4 at.%. Higher concentrations lead to an increase of Tc from 0.24 to 0.43 K as characterized by electrical-transport measurements. A short mean-free path indicates superconductivity in the dirty limit. In addition, small critical-current densities of max. 20 kA/m² point to a large impact of the microstructure.
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| Date |
2017-05-31T08:38:50Z
2017-05-31T08:38:50Z 2011 |
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| Type |
Article
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| Identifier |
The impact of heavy Ga doping on superconductivity in germanium / R. Skrotzki, T. Herrmannsdörfer, V. Heera, J. Fiedler, A. Mücklich, M. Helm, J. Wosnitza // Физика низких температур. — 2011. — Т. 37, № 9-10. — С. 1098–1106. — Бібліогр.: 44 назв. — англ.
0132-6414 PACS: 74.10.+v, 74.78.–w http://dspace.nbuv.gov.ua/handle/123456789/118783 |
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| Language |
en
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| Relation |
Физика низких температур
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| Publisher |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
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