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Structural, transport, magnetic properties and Raman spectroscopy of orthorhombic Y$1-x$CaxMnO3(0 <= x <= 0.5)

M. N. Iliev·B. Lorenz·A. P. Litvinchuk·Y. -Q. Wang·Y. Y. Sun·C. W. Chu
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Abstract

Orthorhombic Y$_{1-x}$Ca$_x$MnO$_3$ ($0 \leq x \leq 0.5$) was prepared under high pressure and the variations with $x$ of its structural, magnetic, electrical properties and the polarized Raman spectra were investigated. The lattice parameters change systematically with $x$. Although there are strong indications for increasing disorder above $x = 0.20$, the average structure remains orthorhombic in the whole substitutional range. Ca doping increases conductivity, but temperature dependence of resistivity $ρ$(T) remains semiconducting for all $x$. The average magnetic exchange interaction changes from antiferromagnetic for $x < 0.08$ to ferromagnetic for $x > 0.08$. The evolution with $x$ of the Raman spectra provides evidence for increasingly disordered oxygen sublattice at $x \geq 0.10$, presumably due to quasistatic and/or dynamical Jahn-Teller distortions.

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M. N. Iliev, B. Lorenz, A. P. Litvinchuk, Y. -Q. Wang, Y. Y. Sun, C. W. Chu. 2004-08-16. Structural, transport, magnetic properties and Raman spectroscopy of orthorhombic Y$1-x$CaxMnO3(0 <= x <= 0.5). https://doi.org/10.1088/0953-8984%2F17%2F21%2F026

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