Effect of Sr2+, Ba 2+ and Ta5+ Ions on Structural and Electrical Properties of BNKT Ceramics. (2015)

• Record Type: Journal Article
• Authors: Rastogi, S.K.; Divya, P.; Praveenkumar, B.; Kumar, Ashavani
• Is Part Of: Materials today. Volume 2:Number 4/5(2015)
• Page Start: 2784
• Page End: 2788
• Publication Date: 2015
• Subjects: BNKT -- Dielectric -- Piezoelectric -- XRD.; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2015.07.277
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: Lead free piezoelectric ceramics [Bi0.5 (Na0.85 K0.15 )]0.98 X0.02 TiO3 (where x= Sr 2+, Ba 2+ ) and Bi0.5 (Na0.85 K0.15 )Ta0.02 Ti0.98 O3 are prepared by conventional solid state reaction method. The structural, dielectric and piezoelectric characteristics of the doped (Sr 2+, Ba 2+, Ta 5+ ) BNKT ceramic systems are investigated and discussed. The XRD results confirm the formation of perovskite phase and no secondary impurity phases, indicating that Sr 2+, Ba 2+ and Ta 5+ ions has diffused respectively into BNKT lattice to form a new solid solution. The average grain sizes of the ceramic samples are studied by scanning electron microscopy technique (SEM). Partial substitution of Ba 2+ (0.142 nm) and Ta 5+ (0.064 nm) ions enhance the dielectric properties due to the enlargement of lattice constant and lattice energy. The P-E hysteresis loops reveal that the BNKT ceramic doped with Ba 2+ ions has the high remnant polarization and rectangularity of the loop due to the larger grain size. Leakage current studies confirm the presence of high leakage current in the case of BNKTB samples because of high conductivity and larger grains size.