Evidence of frustration in the S =1/2 square-lattice antiferromagnet Sr2CuTe1-x WxO6
Abstract
The S =1/2 Heisenberg frustrated square-lattice model, or J1-J2 model, describes systems with competing antiferromagnetic interactions. Magnetic order is Néel type when J1 >> J2 and columnar when J2 >> J1. The nature of the ground state in the highly frustrated J2/J1 0.5 region is under debate with proposals including different valence bond solids and spin liquids. We report experimental evidence of frustration in a tunable J1-J2 model system. Recent neutron scattering experiments by us and ref. have shown the Cu2+ square-lattice double perovskites Sr2CuTeO6 and Sr2CuWO6 to be highly two-dimensional antiferromagnets with J2/J1 = 0.03 (Néel order) and J2/J1 = 7.92 (columnar order), respectively. We have synthesized the solid solution series Sr2CuTe1-x WxO6 0 <= x <= 1, and report the magnetic properties. Magnetic susceptibility χ(T) shows a broad maximum at Tmax = 73 K and 83 K in Sr2CuTeO6 and Sr2CuWO6, respectively. Tmax reaches a minimum of 50 K in the vicinity of x 0.5 coinciding with a maximum in χmax. This suggests the realization of the highly frustrated J1-J2 antiferromagnet near x 0.5.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2017
- Bibcode:
- 2017APS..MARA50009M