Effect Of Sr-substitution On Structural, Dielectric And Impedance Characteristics Of MPB-PZT

Patri Tirupathi¹, Anil Tejomurthula², Nawnit Kumar³, Mukul Pastor^4*, R. N. P. Choudhary⁵

¹Department of Physics, Rajiv Gandhi University of knowledge Technologies, RK Valley 516330, India

²Department of Metallurgical & Materials Engineering, Rajiv Gandhi University of Knowledge Technologies,RK Valley 516330, India

³Department of Physics, Indian Institute of Technology, Kharagpur 721302, India

⁴Department of Physics, Bundelkhand University, Jhansi (U.P.) 284002, India

⁵Department of Physics, Institute of Technical Education and Research SOA University, Bhubaneswar 751 030, India

Adv. Mater. Lett., 2016, 7 (11), pp 918-925

DOI: 10.5185/amlett.2016.6233

Publication Date (Web): Oct 01, 2016

E-mail:mukul.ptr@gmail.com

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Abstract

The polycrystalline sample of Sr-modified Pb(Zr_0.5Ti_0.5)O₃ (i.e. Pb_1-xSr_x(Zr_0.5Ti_0.5)O₃(x = 0.05-0.15)) ceramics were synthesized (close to morph-tropic phase boundary) by a cost effective (solid state reaction) method. Detailed investigation of structural phase transition was carried out using room temperature X-ray diffraction data adopting Rietveld refinement technique. The coexistence of two crystal phases (i.e., tetragonal (P4mm) and rhombohedral (R3c) for x = 0.05, and single tetragonal (P4mm) phase for x = 0.1, 0.15) were observed. Elemental analysis, grain shape and size distribution were studied using scanning electron microscope. The decrease in grain size on increasing Sr²⁺concentration was also observed. Detailed analysis of temperature and frequency dependence of dielectric exhibits the increase in dielectric permittivity as function of Sr²⁺ concentration at room temperature. Beside this, the greatly reduced Curie (T_C) temperature and broadening of dielectric maxima as function of increasing Sr²⁺concentration in PZT was observed. The multiple relaxation processes associated with grain, grain boundaries and interfacial polarization was noted for x=0.05 and x=0.10 to analyze the Nyquist plots. The dominant of grain boundary resistance with increasing in dopent concentration x=0.15 was observed.