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Article Citation - WoS: 3Citation - Scopus: 3Effect of Ionic Substitution on the Structural, Dielectric and Electrical Properties of Bismuth Zinc Niobate Ceramics(Korean Assoc Crystal Growth, inc, 2012) Qasrawi, A. F.; Abu Je'ib, Hussein A.; Mergen, A.; Department of Electrical & Electronics EngineeringThe effects of tin substitution on the structural, dielectric and electrical properties of the Bi1.5Zn0.92Nb1.5O6.92 pyrochlore ceramics have been investigated. Tin atoms was substituted in the A (Bi1.5Zn0.46)-site instead of zinc and in the B ((Zn0.46Nb1.5)-site instead of niobium in accordance to the chemical formulae Bi1.5Zn0.92Nb1.5-xO6.92-x/2 and (Bi1.5-x/3Zn0.46-3x/2Snx)(Nb1.5Zn0.46)O-6.92, for 0.00 <= x <= 0.40 and 0.00 <= x <= 0.60, respectively. A relative single phase formation of the structures was possible for x values less than 0.25 and less than 0.10. Pronounced tunability in the dielectric constant values associated with very low dielectric loss are obtainable by Sn substitution. Furthermore, a frequency invariant but linearly varying temperature dependent dielectric constant is observed. The electrical conductivity decreased by two and one order of magnitude for the A and B-site substitutions, respectively. The temperature-dependent conductivity analysis in the temperature region of 300-500 K, reflected the existence of shallow and deep impurity energy levels being created by the doping process.Article Citation - WoS: 4Citation - Scopus: 2Mechanical Properties and Electrical Resistivity of Sic-Tic Composites With Nitrate Sintering Additives(Korean Assoc Crystal Growth, inc, 2020) So, Sung Min; Hwang, Hee Woong; Yi, Sam Heang; Park, Joo Seok; Kim, Kyoung Hun; Lee, Kwang Ho; Lee, Sung GapWe fabricated SiC-TiC composites by hot-press sintering with aluminum and yttrium nitrate additive and evaluated crystal phase, relative density, microstructure, electrical resistivity and mechanical properties of the sintered body. And the effect of nitrate additive on the densification of SiC-TiC composites was compared with that of Al2O3 and Y2O3 additives. Because nitrate additives were uniformly dispersed in SiC and TiC mixture, it inhibited the growth of crystal grain between each other and formed fine and uniform microstructure, thereby improving mechanical properties and electrical resistivity. The electrical resistivity and flexural strength of the SiC-TiC composite with aluminum and yttrium nitrate additive were 2.3 Omega.cm and 652.3 MPa respectively.
