Spin-glass state and long-range magnetic order in Pb(Fe)_(1/2)Nb_(1/2))O_3 seen via neutron scattering and muon spin rotation

摘要

We have investigated the magnetic ground state of the multiferroic relaxor ferroelectric Pb(Fe_(1/2)Nb_(1/2))O_3 with μSR spectroscopy and neutron scattering. We find that a transition to a partially disordered phase occurs below T=20 K that coexists with long-range antiferromagnetic ordering. The disordered phase resembles a spin glass. No clustering of magnetic ions could be evidenced by μSR so that the coexistence appears homogeneous in the sample.