Abstract
Two new gapless quantum spin-liquid candidates with () moments: the phase of with a -triangular lattice and the 3C phase with a -three-dimensional edge-shared tetrahedral lattice were obtained under high pressure. Both compounds show no magnetic order down to 0.35 K despite Curie-Weiss temperatures of () and (3C), respectively. Below , the magnetic susceptibility of the phase saturates to a constant value , which is followed below 7 K by a linear-temperature-dependent magnetic specific heat () displaying a giant coefficient . Both observations suggest the development of a Fermi-liquid-like ground state. For the 3C phase, the behavior indicates a unique , 3D quantum spin-liquid ground state.
- Received 7 June 2011
DOI:https://doi.org/10.1103/PhysRevLett.107.197204
© 2011 American Physical Society