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arXiv · 0912.1507

Magnetic field induced quantum phase transition of the $S = 1/2$ antiferromagnet $K_2NaCrO_8$

S. Nellutla·M. Pati·Y. -J. Jo·H. D. Zhou·B. H. Moon·D. M. Pajerowski·Y. Yoshida·J. A. Janik·L. Balicas·Y. Lee·M. W. Meisel·Y. Takano·C. R. Wiebe·N. S. Dalal
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Abstract

The magnetic properties of alkali-metal peroxychromate K$_2$NaCrO$_8$ are governed by the $S = 1/2$ pentavalent chromium cation, Cr$^{5+}$. Specific heat, magnetocalorimetry, ac magnetic susceptibility, torque magnetometry, and inelastic neutron scattering data have been acquired over a wide range of temperature, down to 60 mK, and magnetic field, up to 18 T. The magnetic interactions are quasi-two-dimensional prior to long-range ordering, where $T_N = 1.66$ K in $H = 0$. In the $T \to 0$ limit, the magnetic field tuned antiferromagnetic-ferromagnetic phase transition suggests a critical field $H_c = 7.270$ T and a critical exponent $α= 0.481 \pm 0.004$. The neutron data indicate the magnetic interactions may extend over intra-planar nearest-neighbors and inter-planar next-nearest-neighbor spins.

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S. Nellutla, M. Pati, Y. -J. Jo, H. D. Zhou, B. H. Moon, D. M. Pajerowski, Y. Yoshida, J. A. Janik, L. Balicas, Y. Lee, M. W. Meisel, Y. Takano, C. R. Wiebe, N. S. Dalal. 2009-12-08. Magnetic field induced quantum phase transition of the $S = 1/2$ antiferromagnet $K_2NaCrO_8$. https://doi.org/10.1103/physrevb.81.064431

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