Pressure effect on electronic structure and magnetic properties of iron-based high Tс superconductors

• Дата: 2010
• Автори: Grechnev, G.E., Desnenko, V.A., Fedorchenko, A.V., Panfilov, A.S., Gnatchenko, S.L., Zhuravleva, I.P., Volkova, O.S., Vasiliev, A.N., Tsurkan, V.V.
• Формат: Стаття
• Мова: English
• Опубліковано: Донецький фізико-технічний інститут ім. О.О. Галкіна НАН України 2010
• Назва видання: Физика и техника высоких давлений
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/69329
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Pressure effect on electronic structure and magnetic properties of iron-based high Tс superconductors / G.E. Grechnev, V.A. Desnenko, A.V. Fedorchenko, A.S. Panfilov, S.L. Gnatchenko, I.P. Zhuravleva, O.S. Volkova, A.N. Vasiliev, V.V. Tsurkan // Физика и техника высоких давлений. — 2010. — Т. 20, № 4. — С. 60-69. — Бібліогр.: 19 назв. — рос.

Pressure effects on electronic structure and magnetic properties of iron-based superconductors FeSe1−xTex (x ≃ 0, 0.5 and 1.0) and LaFeAsO are investigated. The superconducting transition was observed at TC ≃ 8, 13.6−14.2, and 26 K in FeSe₀.₉₆₃, FeSe₀.₅Te₀.₅, and LaFeAsO₀.₈₅F₀.₁, respectively. The intrinsic magnetic susceptibility χ in the series of FeSe₀.₉₆₃, FeSe₀.₅Te₀.₅ and FeTe is found to increase gradually approximately 10 times as much with Te content. A kink in the low-field dependence of χ(T) was detected at TM ≃ 135 K for LaFeAsO₀.₈₅F₀.₁. The electronic structures and paramagnetic susceptibilities of the studied compounds are calculated ab initio in external magnetic field as a function of atomic volume and structural parameter Z, which specifies the relative height of chalcogen atoms above iron plane. The calculated field-induced magnetic moments and their volume derivatives indicate that these systems are in a close proximity to a quantum critical point. For FeSe and FeTe the calculated paramagnetic susceptibilities reveal a large magnetovolume effect and a drastic sensitivity to parameter Z.