Low-temperature magnetic behavior on the triangular lattice in hexagonal Ba3Tb(BO3)3

Abstract

The hexagonal polymorph of Ba 3 Tb ( BO 3 ) 3 contains Tb 3 + ions on a quasi-2D triangular lattice, resulting in geometric magnetic frustration. Powder samples of Ba 3 Tb ( BO 3 ) 3 have been investigated using specific heat, powder neutron diffraction (PND), inelastic neutron scattering (INS), and muon-spin relaxation spectroscopy ( μ SR ). No long-range magnetic ordering is observed down to the lowest measured temperatures of 75 mK in PND and specific heat data and 1.5 K in the μ SR data. Modeling the INS spectrum using a point charge model suggests that the ground state is a singlet with a low-lying doublet on each of the two crystallographically independent Tb 3 + sites and that both the Tb ions display weak XY single-ion anisotropy.