Investigation of possible quantum spin liquid ground state in 6H-hexagonal perovskite d5 iridates Ba3M4+Ir24+O9 (M=Ti, Zr) using Muon spin r

The 6H-hexagonal perovskite iridates Ba3M4+Ir2O9 with Ir4+ ions located on the vertices of a triangular lattice have been serving as the potential paradigm in search for the novel quantum spin liquids and other exotic quantum magnetic ground states. The M= Ti and Zr demonstrate absence of magnetic ordering via featureless paramagnetic-like dc susceptibility curves as well as missing anomaly in the specific heat data, despite having considerable antiferromagnetic Ir-Ir exchange interaction, thus marking both these d5 iridates as candidate materials for exhibiting strongly spin-orbit entangled dynamic quantum spin liquid ground states, which therefore warrants in-depth local probe muon-spin-relaxation/rotation (�SR) investigations to ascertain the true quantum magnetic ground states and consequently, to authenticate(refute) the dynamic(static) nature of the Ir-magnetic moments.