Local structural investigation of Zr & Ca doped BaTiO3 nanocrystals

Abstract

Barium titanate ceramic is one of the technologically important lead free materials for piezoelectric and tunable capacitor device applications. The technological trend towards decreasing dimension makes it of interest to examine its functional properties at nano-scale due to the miniaturization of electronics devices. In the present work, lead free BCZT ceramics i.e Ba 0.85Ca 0.15Ti 0.96 Zr 0.04 O 3 and Ba0.85Ca0.15Zr0.10Ti0.90O3 has been prepared by high energy ball milling to study the local distortion in lattice due to presence of dopants (Zr, Ca etc) and its effects on the formation of polar nano regions (PNR’s) in nano-structured Ba-based perovskite. XRD, PDF, FESEM, FTIR, TG-DTA are used to structural characterization of BCZT. The dielectric property depends on this local atomic arrangement of Zr and Ca atoms in BaTiO 3 and coexistence of multiple phases. The knowledge of such understanding will lead to the synthesis of lead free BCZT ceramics. The short range and long range structure reported from PDF curve fitting with local and average structure investigate. Very small amount of dopant (Zr, Ca) can considerably modify functional properties like the electrical conductivity and the domain wall mobility. The phase transformation behavior of BCZT powder will be studied with particle size reduction and finally dielectric properties will be correlated with the structure at nano-scale.