Low Temperature Physics: 33, 931 (2007); https://doi.org/10.1063/1.2747068 (4 pages)
Fizika Nizkikh Temperatur: Volume 33, Number 11 (November 2007), p. 1227-1231    ( to contents , go back )

Phase separation in nanoscale samples of (LaSr)MnO3

A.S. Mazur, V.N. Krivoruchko, and I.A. Danilenko

A. Galkin Donetsk Physico-Technical Institute of the National Academy of Sciences of Ukraine 72 R. Luxemburg Str., Donetsk 83114, Ukraine
E-mail: krivoruc@krivoruc.fti.ac.donetsk.ua
pos Анотація:

Received April 4, 2007

Abstract

Comparative investigations of nuclear magnetic resonance spectra and nuclear spin-spin relaxation of 55Mn nuclei have been performed on nanopowders of manganites La0.7Sr0.3MnO3 with different size of particles: 50–200 nm (NP1) and 12 nm (NP2). It is found that in sample NP1 there are two localized ferromagnetic phases (FgM and FbM) with different dynamics of magnetic spins in a wide temperature range. The phase FgM is identified as a ferromagnetic metallic phase due to a double exchange, while the phase FbM is identified as a ferromagnetic phase with a slower holes motion and a weaker double exchange. In sample NP2 only one phase is detected that corresponds to the phase FbM. The results obtained suggest that the stability of the inhomogeneous ferromagnetic state of lanthanum manganites may be limited from below by a characteristic minimum scale.

PACS: 76.60.–k Nuclear magnetic resonance and relaxation;
PACS: 75.30.Kz Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.);
PACS: 75.50.Pp Magnetic semiconductors.

Key words: NMR, manganites, phase separation,

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