Magnetic behaviour of the Bi$_{2-x}$Sr$_{x}$Ir$_{2}$O$_{7}$ pyrochlore

Compounds of the Bi$_{2-x}$Sr$_{x}$Ir$_{2}$O$_{7}$ solid solution have been synthesized by the solid state reaction method. Structural modifications as well the valence states of Iridium have been studied as a function of the strontium content by Rietveld refinements and electrochemical analytical methods. Electrical properties of Bi$_{2-x}$Sr$_{x}$Ir$_{2}$O$_{7}$ show single phase and metallic behaviour in the whole range of compositions. Magnetically this system behaves as a Curie-Weiss paramagnet from 2-300 K. the magnetic moment suggests the presence of Ir$^{5+}$ valence state.