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arXiv · 1607.01846

Crossover from one- to three-dimensional behavior in the S = 1/2 Heisenberg antiferromagnet Cu(N2H5)2(SO4)2

A. Paduan-Filho·A. P. Vieira·J. G. A. Ramon·R. S. Freitas
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Abstract

From experimental and theoretical analyses of magnetic and specific-heat properties, we present the complete magnetic phase diagram of the quasi-one-dimensional antiferromagnet Cu(N$_2$H$_5$)$_2$(SO$_4$)$_2$. On cooling and at zero magnetic field this compound enters a one-dimensional regime with short-range magnetic correlations, marked by a broad maximum in the specific heat and magnetic susceptibility at $T_\mathrm{max}\sim 2\,\mathrm{K}$, followed by an ordered antiferromagnetic phase below $T_\mathrm{N}\sim 1\,\mathrm{K}$ induced by small interchain couplings. The intermediate-temperate one-dimensional regime can be modeled using exact quantum-transfer-matrix calculations, which perfectly describe the nonmonotonic behavior of T_max as a function of the magnetic field, giving $J = 4.25\,\mathrm{K}$ for the intrachain exchange parameter. The analysis of magnetic specific-heat and susceptibility data at low temperature indicates that the interchain exchange couplings are an order of magnitude smaller than the coupling inside the chains.

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A. Paduan-Filho, A. P. Vieira, J. G. A. Ramon, R. S. Freitas. 2016-07-07. Crossover from one- to three-dimensional behavior in the S = 1/2 Heisenberg antiferromagnet Cu(N2H5)2(SO4)2. https://doi.org/10.1088/0953-8984/28/50/506004

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