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arXiv · 0708.2550

Triplet Dimerization Crossover Driven by Magnetic Frustration in In2VO5

S. A. J. Kimber·M. A. de Vries·J. Sanchez-Benitez·K. V. Kamenev·J. P. Attfield
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Abstract

In2VO5, containing magnetically frustrated zig-zag chains, shows a remarkable magnetic crossover at 120 K between paramagnetic states with positive (17 K) and negative (-70 K) Weiss temperatures. Magnetic moment and entropy data show that the V4+ S = 1/2 spins condense into S = 1 triplet dimers below the crossover. A further freezing of the antiferromagnetically coupled triplet dimers into a global singlet state is observed at 2.5 K, with no long range magnetic order down to 0.42 K and in fields up to 9 T. No structural V-V dimerization is observed by high-resolution X-ray diffraction down to 10 K, but a subtle lattice anomaly evidences a spin-lattice coupling in the triplet dimer state. This is assigned to longitudinal oxygen displacement modes that reduce frustration within the chains and so couple to the spin dimer fluctuations.

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S. A. J. Kimber, M. A. de Vries, J. Sanchez-Benitez, K. V. Kamenev, J. P. Attfield. 2007-08-19. Triplet Dimerization Crossover Driven by Magnetic Frustration in In2VO5. https://doi.org/10.1103/physrevb.77.014428

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