Features of the structure and the Mössbauer effect in solid solutions of the $(1-x)$Pb(Fe$_{1/2}$Nb$_{1/2}$)O$_3$—$x$Pb(Fe$_{2/3}$W$_{1/3}$)O$_3$ system

In this work, we study solid solutions of the system $(1-x)$Pb(Fe$_{1/2}$Nb$_{1/2}$)O$_3$—$x$Pb(Fe$_{2/3}$W$_{1/3}$)O$_3$ using X-ray diffraction and Mössbauer spectroscopy. To obtain solid solutions, we used the method of two-stage solid-phase synthesis and sintering according to conventional ceramic technology. Pure solid solutions of the$(1-x)$Pb(Fe$_{1/2}$Nb$_{1/2}$)O$_3$—$x$Pb(Fe$_{2/3}$W$_{1/3}$)O$_3$ system have been obtained. A deviation of the cell parameters from the Vegard rule was revealed, which indicates the stratification of the structure into microregions differing in composition. The clustering of Fe$^{3+}$ ions in the B-sublattice has been find. The introduction of PbFe$_{2/3}$W$_{1/3}$O$_3$ into the system leads to partial ordering of cations in the B position was shown.