Structure and magnetism of S = 1/2 kagome antiferromagnets NiCu3(OH)6Cl2 and CoCu3(OH)6Cl2

J Phys Condens Matter. 2013 Jan 16;25(2):026003. doi: 10.1088/0953-8984/25/2/026003. Epub 2012 Nov 28.

Abstract

We have successfully synthesized S = 1/2 kagome antiferromagnets MCu(3)(OH)(6)Cl(2) (M = Ni and Co) by a hydrothermal method with a rotating pressure vessel. Structural characterization shows that both compounds have similar crystal structure to ZnCu(3)(OH)(6)Cl(2) with R3m symmetry. As with ZnCu(3)(OH)(6)Cl(2), the compounds show no obvious hysteresis at 2 K. A spin-glass transition is found in both NiCu(3)(OH)(6)Cl(2) and CoCu(3)(OH)(6)Cl(2) at low temperatures (6.0 and 3.5 K respectively) by AC susceptibility measurements. This indicates no long-range magnetic order and a strong spin frustration. The substitution of Zn(2+) by magnetic ions Ni(2+) or Co(2+) effectively enhances the interlayer exchange coupling and changes the ground state of the kagome spin system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computer Simulation
  • Magnets*
  • Materials Testing
  • Metals / chemistry*
  • Models, Chemical*
  • Models, Molecular*

Substances

  • Metals