Muon spin relaxation study of the proton conductor HZr2(PO4)3

Muon spin relaxation has been used to study the implantation and dynamics of muons in the proton conductor HZr2(PO4)3 as a function of temperature. Muons are implanted at two different sites. One can be identified as H2Oμ+ on the basis of its low temperature second moment, Δω02. The other site is less well defined, Δω02 suggests P-O-μ with an associated hydrogen. Dynamic averaging of the nuclear field is observed for H2Oμ+ above ca. 160 K, whereas no dynamic processes are observed for the P-O-μ below 400 K. Above 400 K, further averaging of the nuclear field of both sites takes place which is attributed to translational diffusion of the muon through the lattice.