Distorted Kagome Lattice Generated by a Unique Orbital Arrangement in the Copper Mineral KCu3As2O7(OH)3

Abstract

We study polycrystalline samples of KCu3As2O7(OH)3, a new candidate spin-1/2 kagome antiferromagnet, by magnetic susceptibility and heat capacity measurements above 2 K. The unique arrangement of the 3z2 - r2 and x2 - y2 orbitals on the Cu2+ kagome net is noted and compared to the orbital patterns found in other kagome minerals. It is suggested that this orbital arrangement gives rise to one antiferromagnetic and two ferromagnetic interactions on isosceles triangles forming a highly distorted kagome lattice. KCu3As2O7(OH)3 is found to show an antiferromagnetic long-range order at T_N = 7.2 K. Remarkably, a spin entropy is more gradually released upon cooling below T_N compared with a conventional magnetic long-range order, which may originate from the geometrical frustration still present in this highly distorted kagome lattice.

5 pages, 4 figures

References in corpus (6)

• Vesignieite BaCu3V2O8(OH)2 as a Candidate Spin-1/2 Kagome Antiferromagnet
• Unconventional Dynamics in Triangular Heisenberg Antiferromagnet NaCrO2
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Cited by in corpus (8)

• Quantum Magnetism in Minerals
• Kagome-Triangular Lattice Antiferromagnet NaBa2Mn3F11
• Magnetic phase diagrams and magnetization plateaus of the spin-1/2 antiferromagnetic Heisenberg model on square-kagome lattice with three nonequivalent exchange interactions
• Magnetization plateaus in the spin-1/2 antiferromagnetic Heisenberg model on a kagome-strip chain
• Magnetic Properties of the Spin-1/2 Deformed Kagome Antiferromagnet Edwardsite
• Helical order and multiferroicity in the $S=1/2$ quasi-kagome system KCu${}_3$As${}_2$O${}_7$(OD)${}_3$
• Phase diagram of multiferroic KCu${}_3$As${}_2$O${}_7$(OD)${}_3$
• Magnetic anisotropy effect on stabilizing magnetization plateaus of kagome strip chain Heisenberg antiferromagnets