Antiferromagnetic resonance in charge ordering state of Pr0.5Ca0.5MnO3−δ single crystal

Abstract An antiferromagnetic resonance (AFMR) is observed in the charge ordered antiferromagnetic phase of Pr 0.5 Ca 0.5 MnO 3− δ single crystal for the first time. Above the Neel temperature, T N =173 K, a paramagnetic resonance with g =2.0 is observed. There is no significant change of the resonance spectra at the charge ordering transition temperature, T CO =242 K. Below T N , a branch of AFMR is found. Since the resonance field of this mode increases linearly as the frequency is decreased, this branch is assigned as the spin-flop mode. Below 60 K, the critical fields, B C , evaluated as the extrapolation of this mode to zero frequency agree well with the insulator–metal transition fields, B CO , at which the melting of the charge-ordering phase occurs. Present results indicate that the temperature dependence of B CO is affected by the temperature dependence of B C .