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Crystal growth, transport phenomena and two gap superconductivity in the mixed alkali metal {K(1-z)Na(z)}(x)Fe(2-y)Se2 iron selenideстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 2 сентября 2014 г.
- Авторы: Maria Roslova, Svetoslav Kuzmichev, Tatiana Kuzmicheva, Yevgeny Ovchenkov, Min Liu, Igor Morozov, Aleksandr Boltalin, Andrey Shevelkov, Dmitry Chareev, Aleksandr Vasiliev
- Журнал: CrystEngComm
- Том: 16
- Номер: 30
- Год издания: 2014
- Издательство: Royal Society of Chemistry
- Местоположение издательства: United Kingdom
- Первая страница: 6919
- Последняя страница: 6928
- DOI: 10.1039/C3CE42664E
- Аннотация: Using the self-flux technique we grew superconducting (K_{1-z}Na_z)_{x}Fe_{2-y}Se_2 (z = 0.3) single crystals. The EDX mapping revealed the uniform elements distribution on the crystal surface while the XRD measurements indicate that the crystals are compositionally inhomogenous on nanoscale. The physical properties of the as-prepared sample are characterized by electrical resistivity, magnetization and specific heat measurements. Resistivity measurements show the onset of the superconducting transition at 33 K and zero resistivity at 31.7 K. The large upper critical field H_{c2}(0) was estimated as high as about of 140 T for the in-plane field and 38 T for the out-of-plane field. The anisotropy of H_{c2}^{ab}(0)/H_{c2}^{c}(0) and coherence lengths \xi^{ab}(0)/\xi^{c}(0) was found to be around 3.7. The pioneer studies by multiple Andreev reflections effect spectroscopy ("break-junction" technique) revealed the presence of two anisotropic superconducting gaps \Delta_L\,=\,(9.3\pm1.5)\,meV, \Delta_S\,=\,(1.9\pm0.4)\,meV, and provided measuring of the \Delta_L(T) temperature dependence. The BCS-ratio for the large gap 2\Delta_L/k_BT_c^{bulk}\,\approx\,6.3 points to a strong electron-boson coupling in the "driving" condensate characterized by \Delta_L order parameter. [arXiv: cond mat/1312.6441]
- Добавил в систему: Кузьмичев Светослав Александрович