Mössbauer Studies of PbFe_0.5Nb_0.5O₃- PbFe_0.5Sb_0.5O₃Multiferroic Solid Solutions

Abstract

Perovskite (1-x)PbFe0.5Nb0.5O3 - xPbFe0.5Sb0.5O3 solid solutions have been obtained for the first time using a high-pressure synthesis method. X-ray diffraction studies revealed a gradual increase of long-range compositional order degree S in the arrangement of Fe3+ and Sb5+(Nb5+) cations beginning from x ≈ 0.6. Room-temperature Mössbauer spectra of compositions with S > 0.6 besides doublet include also a singlet component; its fraction increases with S and reaches ≈0.8 for pure PbFe0.5Sb0.5O3. Temperature dependences of the relative intensity of doublet (singlet) component of Mössbauer spectra exhibit two anomalies which are supposed to correspond to the antiferromagnetic phase transition temperatures in the regions with differing S values. Magnetic phase transition in PbFe0.5Sb0.5O3 takes place at ≈ 25 K.