μSR study on the frustrated trillium lattice antiferromagnet K2Co2(SO4)3

We propose to study a frustrated trillium lattice compound K2Co2(SO4)3 where Co(2+) ions feature a Jeff = ½ ground state at low temperatures. The compound exhibits the onset of an antiferromagnetic ordering around T* ~ 0.6 K in heat capacity. With the applied field of 1 T, the transition is completely suppressed, indicating a field-induced dynamic state similar to the isostructural compound K2Ni2(SO4)3. With a large frustration ratio of 16 and enhanced quantum fluctuations because of Jeff = ½ ground state, K2Co2(SO4)3 provides an ideal platform to realize the quantum spin liquid state. We propose to measure a series of zero-field measurements complemented by longitudinal field decoupling scans to verify the presence of static and/or dynamic magnetic order.