Charge carrier self-organization in ferroelectromagnetic semiconductors Eu₀.₈Ce₀.₂Mn₂O₅

• Дата: 2010
• Автори: Golovenchits, E.I., Sanina, V.A., Zalesskii, V.G., Scheglov, M.P.
• Формат: Стаття
• Мова: English
• Опубліковано: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2010
• Назва видання: Физика низких температур
• Теми: Магнитоэлектрические эффекты в сегнетомагнетиках
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/117176
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Charge carrier self-organization in ferroelectromagnetic semiconductors Eu₀.₈Ce₀.₂Mn₂O₅ / E.I. Golovenchits, V.A. Sanina, V.G. Zalesskii, M.P. Scheglov // Физика низких температур. — 2010. — Т. 36, № 6. — С. 654–664. — Бібліогр.: 23 назв. — англ.

The state with a giant permittivity (ε~10⁴) and ferromagnetism has been observed above 185 K (including room temperature) in single crystals of diluted semiconductor manganite–ferroelectromagnetic Eu₀.₈Ce₀.₂Mn₂O₅ in the investigations of x-ray diffraction, dielectric and magnetic properties, conductivity. X-ray diffraction study has revealed a layered superstructure along the c axis at room temperature. A model of the state with a giant ε including as-grown 2D layers with doping impurities, charge carriers, and double-exchange coupled Mn³⁺–Mn⁴⁺ ion pairs is suggested. At low temperatures these layers form isolated electrically neutral small-size 1D superlattices, in which de Haas van Alphen oscillations were observed. As temperature grows and hopping conductivity increases, the charge carrier self-organization in the crystal cause formation of a layered superstructure consisting of charged layers (with an excess Mn³⁺ concentration) alternating with dielectric layers of the initial crystal — the ferroelectricity state due to charge ordering. Ferromagnetism results from double exchange between Mn³⁺ and Mn⁴⁺ ions through of charge carriers in the charged layers.