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arXiv · 1011.6423

Heat capacity of the site-diluted spin dimer system Ba3(Mn1-xVx)2O8

E. C. Samulon·M. C. Shapiro·I. R. Fisher
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Abstract

Heat capacity and susceptibility measurements have been performed on the diluted spin dimer compound Ba3(Mn1-xVx)2O8. The parent compound Ba3Mn2O8 is a spin dimer system based on pairs of antiferromagnetically coupled S = 1, 3d2 Mn5+ ions such that the zero field groundstate is a product of singlets. Substitution of non-magnetic S = 0, 3d0 V5+ ions leads to an interacting network of unpaired Mn moments, the low temperature properties of which are explored in the limit of small concentrations, 0<x<0.05. The zero-field heat capacity of this diluted system reveals a progressive removal of magnetic entropy over an extended range of temperatures, with no evidence for a phase transition. The concentration dependence does not conform to expectations for a spin glass state. Rather, the data suggest a low temperature random singlet phase, reflecting the hierarchy of exchange energies found in this system.

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E. C. Samulon, M. C. Shapiro, I. R. Fisher. 2011-08-15. Heat capacity of the site-diluted spin dimer system Ba3(Mn1-xVx)2O8. https://doi.org/10.1103/physrevb.84.054417

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