RT Journal Article A1 Piyush R. DAS,B. N. PARIDA,R. PADHEE,R. N. P. CHOUDHARY; AD Department of Physics, Institute of Technical Education & Research, 印度 ; Department of Physics, Institute of Technical Education & Research, 印度 ; Department of Physics, Institute of Technical Education & Research, 印度 ; Department of Physics, Institute of Technical Education & Research, 印度 T1 Electrical properties of Na2Pb2R2W2Ti4V4O30 (R = Dy, Pr) ceramics YR 2013 IS 2 vo 2 OP 112-OP 118 K1 microstructure;electrical properties;ferroelectricity;ceramics;impedance spectroscopy AB The polycrystalline samples of complex tungsten bronze (TB) Na2Pb2R2W2Ti4V4O30 (R=Dy, Pr) compounds were prepared by solid-state reaction technique. Room- temperature preliminary structural studies confirm the formation of the compounds in the orthorhombic crystal system. Detailed studies of electrical properties of the materials using complex impedance spectroscopy technique exhibit that the impedance and related parameters are strongly dependent upon temperature and microstructure (bulk, grain boundary, etc). An observation of negative temperature coefficient of resistance (NTCR) suggests the materials have semiconducting properties. The variation of AC conductivity with temperature shows a typical Arrhenius behavior of the materials. Both the samples obey Jonscher’s universal power law. The existence of hopping mechanism in the electrical transport processes in the system with non-exponential type of conductivity relaxation is confirmed by electrical modulus analysis. SN 2226-4108 LA EN