UC Berkeley

We synthesize homogeneous compositions of NaLuxYb1-xSe2, connecting nonmagnetic NaLuSe2 to the triangular lattice spin liquid candidate NaYbSe2. Thermal and magnetic properties are studied as the system evolves from one with dilute magnetic defects to one of a dense magnetic lattice. The field- and temperature-dependent heat capacity show the carriers of entropy cross over from isolated magnetic ions to a correlated lattice born from spin dimers. For the dilute system we estimate the single-ion anisotropy (g/g=3.13) and also the dimer exchange couplings J (=5.4 K) and J (=9.6 K), in order to draw comparison to the half-doped and full magnetic compounds.