We study the consequences of in-plane (Dp) and out-of-plane (Dz) Dzyaloshinsky-Moriya (DM) interactions on the thermodynamic properties of spin- 1 2 Heisenberg model on the kagome lattice using numerical linked cluster expansions and exact diagonalization and contrast them with those of other perturbations such as exchange anisotropy and dilution. We find that different combinations of the DM anisotropies lead to a wide variety of thermodynamic behavior, which are quite distinct from those of most other perturbations. We argue that the sudden upturn seen experimentally in the susceptibility of the material Zn Cu3 (OH)6 Cl2 can be understood in terms of Dzyaloshinsky-Moriya anisotropies with Dp > Dz. We also show that the measured specific heat of the material puts further constraints on the allowed DM parameters.
|Physical Review B - Condensed Matter and Materials Physics
|Published - Nov 2 2007
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics