Low temperature magnetic studies on PbFe_0.5Nb_0.5O₃ multiferroic

PbFe_0.5Nb_0.5O₃ (PFN), a well-known A(B′_1/2B″_1/2)O₃ type multiferroic, was successfully synthesized in single phase by a single step solid state reaction method. The single phase PFN was characterized through XRD, microstructure through SEM, and magnetic studies were carried out through a temperature dependent vibrating sample magnetometer (VSM) and neutron diffraction (ND) measurements. PFN exhibits a cusp at around 150 K in the temperature dependent magnetic susceptibility corresponding to the Néel temperature (T_N1) and another peak around 10 K (T_N2) corresponding to spin-glass like transition. In the temperature dependent ND studies, a magnetic Bragg peak appears at Q=1.35 Å⁻¹ (where Q=4πsinθ/λ, is called the scattering vector) below T_N (150 K) implying antiferromagnetic (AFM) ordering in the system. On the basis of Rietveld analysis of the ND data at T=2 K, the magnetic structure of PFN could be explained by a G-type antiferromagnetic structure