Frustrated spin-1/2 dimer compound <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi mathvariant="normal">K</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Co</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mi>Se</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math> with easy-axis anisotropy
Ruidan Zhong, Shu Guo, Loi T. Nguyen, R. J. Cava
Abstract
Magnetic susceptibility, magnetization, and specific-heat measurements under both in-plane and out-of-plane field on ${\mathrm{K}}_{2}{\mathrm{Co}}_{2}{(\mathrm{Se}{\mathrm{O}}_{3})}_{3}$ single crystals are reported. The Co dimers in this compound, which are made from face-sharing effective spin-1/2 $\mathrm{Co}{\mathrm{O}}_{6}$ octahedra, sit on the corners of a geometrically frustrating triangular planar lattice. No long-range magnetic ordering is found down to 0.35 K, which, together with the large negative Curie-Weiss temperature obtained from fitting the temperature-dependent magnetic susceptibility, indicates that the system is magnetically frustrated. Analysis of the field and orientation dependence of the magnetic and thermodynamic properties suggests the presence of an easy-axis anisotropy. The magnetic fluctuations present due to geometric frustration are more resistant to an in-plane field than a perpendicular-to-plane field.