Nonmagnetic impurity effects of the spin disordered state in the triangular antiferromagnet NiGa 2S 4 were studied through magnetic and thermal measurements for Ni 1-xZn xGa 2S 4 (0:0 ≤ x ≤ 0:3). Only 1% substitution is enough to strongly suppress the coherence observed in the spin disordered state. However, the suppression is not complete and the robust feature of the T 2- dependent specific heat and its scaling behavior with the Weiss temperature indicate the existence of a coherent Nambu-Goldstone mode. The absence of either conventional magnetic order or bulk spin freezing suggests a novel symmetry breaking of the ground state.
ASJC Scopus subject areas
- Physics and Astronomy(all)