Mossbauer Studies of PbFe0.5Nb0.5O3 - PbFe0.5Sb0.5O3 Multiferroic Solid Solutions

Perovskite (1-x)PbFe0.5Nb0.5O3 - xPbFe(0.5)Sb(0.5)O(3) 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 approximate to 0.6. Room-temperature Mossbauer spectra of compositions with S > 0.6 besides doublet include also a singlet component; its fraction increases with S and reaches approximate to 0.8 for pure PbFe0.5Sb0.5O3. Temperature dependences of the relative intensity of doublet (singlet) component of Mossbauer 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 approximate to 25K.