μSR study on multi-layered HgBa2Ca4Cu5Oy (Hg-1245) superconductor

We have carried out zero-field muon spin relaxation (ZF-μSR) measurements in multi-layered HgBa 2 Ca 4 Cu 5 O y (Hg-1245) superconductor with T c of 108 K. The variation of ZF-μSR time spectra from Gaussian-type to exponential-type behavior was observed with decreasing temperature below 60 K and the muon precessions were also observed below 45 K. These results indicate the appearance of a static magnetic order of Cu moments at muon sites below T c . Compared with the results of NMR measurements, they suggest that this magnetic order is caused in three under-doped inner planes of five CuO 2 planes in Hg-1245.