Observation of the strain-driven charge-ordered state in La₀.₇Ca₀.₃MnO₃₋δ thin film with oxygen deficiency

• Дата: 2003
• Автори: Prokhorov, V.G., Komashko, V.A., Kaminsky, G.G., Svetchnikov, V.L., Zandbergen, H.W., Lee, Y.P., Park, J.S., Kim, K.W.
• Формат: Стаття
• Мова: English
• Опубліковано: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2003
• Назва видання: Физика низких температур
• Теми: Электpонные свойства металлов и сплавов
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/128785
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Observation of the strain-driven charge-ordered state in La₀.₇Ca₀.₃MnO₃₋δ thin film with oxygen deficiency / V.G. Prokhorov, V.A. Komashko, G.G. Kaminsky, V.L. Svetchnikov, H.W. Zandbergen, Y.P. Lee, J.S. Park, K.W. Kim // Физика низких температур. — 2003. — Т. 29, № 2. — С. 161-168. — Бібліогр.: 23. назв. — англ.

The magnetic and transport properties of La₀.₇Ca₀.₃MnO₃₋δ films with an oxygen deficiency (δ≃ 0.1) and a La₀.₉Ca₀.₁MnO₃ film with the stoichiometric oxygen content are investigated in a wide temperature range. It is shown that the charge-ordered insulating (COI) state is observed for a La₀.₇Ca₀.₃MnO₂.₉ film with thickness d ≤ 30 nm, which manifests mainly a cubic crystal structure with an anomalously small lattice parameter for this composition. An increase in the film thickness (d ≃ 60 nm) leads to a structural transition from the lattice-strained cubic to the relaxed rhombohedral phase, is accompanied by a shift of the Curie point (TC) to lower temperature and a frustration of the COI state. The magnetic and transport properties of the La₀.₇Ca₀.₃MnO₂.₉ film with d ≃ 60 nm are similar to those exhibited by the optimally oxygen-doped La₀.₉Ca₀.₁MnO₃ film. It is concluded that the formation of the COI state in the La₀.₇Ca₀.₃MnO₃₋δ compound is governed by a compression of the crystal lattice rather than accumulation of oxygen vacancies, the low doping of the substituted divalent ions, or electronic phase separation.