We present the highly frustrated phenomena observed in YbAl 3C3 with a spin gap. The inelastic neutron spectra of low-lying magnetic excitations at low temperatures are quite similar to those of SrCu2(BO3)2 and (CuCl)LaNb2O 7 that exhibit a dimer ground state in a two-dimensional quantum spin system. The structure of the first excited triplet state is directly clarified by inelastic neutron scattering experiments with a higher energy resolution. Furthermore, it becomes clear that the characteristic magnetic excitations remain within a high-temperature region. The result of the specific heat measurement also shows an anomaly associated with the formation of dimerized Yb ions. We conclude that a longrange magnetic order is suppressed by a large geometrical spin frustration, resulting in the stabilization of the dimer ground state.
- Frustrated triangular lattice
- Inelastic neutron scattering
- Spin-singlet ground state
ASJC Scopus subject areas
- Physics and Astronomy(all)