Quantum antiferromagnet bluebellite comprising a maple-leaf lattice made of spin-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>1</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn><mml:mspace width="0.16em"/><mml:msup><mml:mrow><mml:mi>Cu</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math> ions
Yuya Haraguchi, Akira Matsuo, Koichi Kindo, Zenji Hiroi
Abstract
Spin-1/2 maple-leaf lattice antiferromagnets are expected to show interesting phenomena originating from frustration effects and quantum fluctuations. We report the hydrothermal synthesis of a powder sample of bluebellite ${\mathrm{Cu}}_{6}\mathrm{I}{\mathrm{O}}_{3}{(\mathrm{OH})}_{10}\mathrm{Cl}$ as a first potential candidate. Magnetization and heat capacity measurements reveal moderate frustration with a Curie-Weiss temperature of $--35\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, and a magnetic transition at ${T}_{N}=17\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. Surprisingly, the magnetic susceptibility and heat capacity above ${T}_{N}$ are well reproduced by the Bonner-Fisher model, which suggests that a one-dimensional spin correlation with a magnetic interaction of 25 K occurs in the apparently two-dimensional lattice. This emergent one-dimensionality cannot be explained by orbital ordering or dimensional reduction due to geometrical frustration. We believe that there is an unknown mechanism to cause one-dimensionality in the spin-1/2 maple-leaf lattice antiferromagnet.