Non-magnetic ion site disorder effects on the quantum magnetism of a spin-1/2 equilateral triangular lattice antiferromagnet.

With the motivation to study how non-magnetic ion site disorder affects the quantum magnetism of BaCoSbO, a spin-1/2 equilateral triangular lattice antiferromagnet, we performed DC and AC susceptibility, specific heat, elastic and inelastic neutron scattering measurements on single crystalline samples of BaSrCoSbOwith Sr doping on non-magnetic Baion sites. The results show that BaSrCoSbOexhibits (i) a two-step magnetic transition at 2.7 K and 3.