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arXiv · 0810.0679

Magnetic crossover and complex excitation spectrum of the ferromagnetic/antiferromagnetic spin-1/2 chain system alpha-TeVO4

V. Gnezdilov·P. Lemmens·A. A. Zvyagin·V. O. Cheranovskii·K. Lamonova·Yu. G. Pashkevich·R. K. Kremer·H. Berger
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Abstract

We report magnetic susceptibility, specific heat, and Raman scattering investigations of alpha-TeVO4 containing V-O edge-sharing chains. These chains promote a system of ferromagnetic/antiferromagnetic spin-1/2 Heisenberg alternating exchange chains with pronounced spin frustration. The magnetic susceptibility and Raman scattering evidence a crossover at T* = 85 K with different slopes of the reciprocal susceptibility and a magnetic phase transition into a long-range-ordered state at Tc = 16 K. From Raman scattering data a strong mutual coupling between lattice and magnetic degrees of freedom is deduced. A comparison to model calculations and prior Raman scattering on other chain systems yield a plausible interpretation of the microscopic mechanism for the crossover behavior.

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V. Gnezdilov, P. Lemmens, A. A. Zvyagin, V. O. Cheranovskii, K. Lamonova, Yu. G. Pashkevich, R. K. Kremer, H. Berger. 2008-10-03. Magnetic crossover and complex excitation spectrum of the ferromagnetic/antiferromagnetic spin-1/2 chain system alpha-TeVO4. https://doi.org/10.1103/physrevb.78.184407

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