The isotope effect and phase separation in (La(0.5)Pr(0.5))(0.7)Ca(0.3)MnO(3) films: Optical data / Loshkareva NN,Sukhorukov YP,Gan'shina EA,Mostovshchikova EV,Kumaritova RY,Moskvin AS,Panov YD,Gorbenko OY,Kaul' AR // JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS. - 2001. - V. 92, l. 3. - P. 462-473.

ISSN/EISSN:

1063-7761 / нет данных

Type:

Article

Abstract:

A new approach to the study of phase separation in lanthanum manganites is proposed based on the combined investigation of their optical and magnetooptical characteristics providing information about the conducting and ferromagnetic regions, respectively. Effects of the (18)O isotope substitution for (16)O in the epitaxial films of (La(0.5)Pr(0.5))(0.7)Ca(0.3)MnO(3) (grown on SrTiO(3) or LaAlO(3) substrates) upon the IR absorption spectra and the equatorial Kerr effect measured in the 1.5-3.8 eV range were studied. A giant drop in the temperature of maximum resistance of the film grown on SrTiO(3) and disappearance of the metal-insulator transition in the film on LaAlO(3) , observed upon the isotope exchange, are accompanied by a decrease in the contribution of free charge carriers to the absorption spectra, by the appearance of bands due to localized states, and by a decrease in magnitude of the equatorial Kerr effects. Measurements of the Kerr effect and the temperature variation of the optical transmission show evidence of the presence of ferromagnetic metal regions in the (18)O-isotope-substituted (La(0.5)Pr(0.5))(0.7)Ca(0.3)MnO(3)/LaAlO(3) film at low temperatures, with a general semiconductor character of the resistivity behavior in the entire temperature range studied. Changes observed in the absorption spectra are explained based on a model of the pseudo-Jahn-Teller polar centers and phase separation. The optical and magnetooptical data show evidence of a percolation nature of the giant isotope effect in manganites. (C) 2001 MAIK ``Nauka/Interperiodica{''}.

Author keywords:

PEROVSKITE MANGANITES; CONDUCTIVITY SPECTRA; METAL TRANSITION; THIN-FILMS; LA1-XSRXMNO3; SHIFT; STATE; SUBSTITUTION; TEMPERATURE; PERCOLATION

DOI:

10.1134/1.1364743

Web of Science ID:

ISI:000167759400010

Соавторы в МНС:

Другие поля

Поле	Значение
Publisher	MAIK NAUKA/INTERPERIODICA/SPRINGER
Address	233 SPRING ST, NEW YORK, NY 10013-1578 USA
Language	English
Keywords-Plus	PEROVSKITE MANGANITES; CONDUCTIVITY SPECTRA; METAL TRANSITION; THIN-FILMS; LA1-XSRXMNO3; SHIFT; STATE; SUBSTITUTION; TEMPERATURE; PERCOLATION
Research-Areas	Physics
Web-of-Science-Categories	Physics, Multidisciplinary
Author-Email	eagan@magn.phys.msu.su
ResearcherID-Numbers	Loshkareva, Natalia/K-1587-2013 Sukhorukov, Yuri/J-3588-2013 Panov, Yury/M-3617-2016 Mostovshchikova, Elena/J-3623-2013
ORCID-Numbers	Loshkareva, Natalia/0000-0002-1701-8712 Sukhorukov, Yuri/0000-0002-8874-1019 Panov, Yury/0000-0001-5751-2400 Mostovshchikova, Elena/0000-0001-8527-3195
Number-of-Cited-References	40
Usage-Count-Since-2013	3
Journal-ISO	J. Exp. Theor. Phys.
Doc-Delivery-Number	416BL