Ba 5 SmZr 3 V 7 O 30 is a new tungsten bronze structured ceramic compound prepared by substituting Zr at Ti site in Ba 5 GdTi 3 V 7 O 30 following high-temperature solid-state reaction route. The X-ray diffraction analysis of the compound confirms the formation of single-phase orthorhombic structures at room temperature. Surface morphology of the compound was studied by scanning electron microscopy. Using a Hioki LCR meter, the effects of temperature (32˚C -500˚C) and frequency (10 2 -10 6 Hz) on structural and electrical properties were studied. Detailed analysis of impedance parameters furnishes a better conception of the electrical properties and type of relaxation processes in the material. The plateau region of the Z'~ frequency plot also indicates the presence of relaxation process in the material. The bulk resistance is observed to be decreased with rise in temperature showing a typical negative temperature coefficient of resistance (NTCR) behavior.

A series of compounds Ba 5-x Sr x GdTi 3 V 7 O 30 (x = 0-5), belonging to tungsten bronze family were prepared by a high-temperature solid-state reaction route. Using X-Ray diffraction technique and Scanning Electron Micrograph, the formation and surface morphology of the compounds were studied. The X-Ray diffraction study informs the formation of single-phase orthorhombic structures. The substitution of Sr ion with increasing concentration in the compounds as per formula resulted in a variation of the electrical properties. Study of electrical properties using impedance analyzer exhibits: 1) the presence of negative temperature coefficients of resistance (NTCR) behavior; 2) presence of temperature dependent electrical relaxation phenomena; 3) evidences of single electrical relaxation attributed to the presence of bulk contribution to the electrical properties for pure Ba 5 GdTi 3 V 7 O 30 compound; 4) an enhancement in the barrier to the mobility of charge carriers on Sr-substitution. The effects of Sr on changes in the electrical conductivity as a function of temperature at different frequency are described based on impedance spectrum analysis.