Magnetic ground state of new ilmenite oxide CoIrO3 studied by muSR

We propose to perform muon spin relaxation experiment on a new ilmenite compound CoIrO3. Honeycomb-based iridates, ruthenium chloride, and cobaltates are recently attracting attention as a possible realization of Kitaev spin liquid. However, most candidate materials undergo magnetic ordering instead of spin-liquid state. We explored new honeycomb cobaltates by employing soft-chemical synthesis and obtained ilmenite-type CoIrO3. The compound may possess two different Kitaev honeycomb planes composed of Co2+ and Ir4+. Magnetic susceptibility of CoIrO3 shows anomalies at 115 and 80 K, but only subtle features are seen in specific heat. Therefore, the presence of magnetic order is not conclusive yet. To pin down this point, we perform ZF-muSR experiments. In addition, to study the spin dynamics, longitudinal-field measurements will be conducted. This experiment will give a clue for the potential complex magnetism of this unique Kitaev magnet.