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Manganites at Low Temperatures and Light Doping:Band Approach and Percolation

Lev P. Gor`kov·Vladimir Z. Kresin
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Abstract

A tight-band model is employed for the $e_{2g}$-orbitals in manganites. It is shown that a large intraatomic Hund's coupling, $J_H$ and the resulting double-exchange mechanism lead to antiferromagnetic ordering along one of the cubic axis stabilized by the cooperative JT effect which further decreases the band energy of electrons. As a result, LaMnO$_3$ is a band insulator built of 2D ferromagnetic layers. The critical concentration $x_c\simeq 0.16$, for onset of ferromagnetic and metallic behavior at low temperatures in La$_{1-x}$Sr$_x$MnO$_3$ and the phase transition are treated in the percolation approach.

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Lev P. Gor`kov, Vladimir Z. Kresin. 1998-04-30. Manganites at Low Temperatures and Light Doping:Band Approach and Percolation. https://arxiv.org/abs/cond-mat/9804328

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