Size-Dependent Structural And Electrical Properties Of Lead-Free Bcst Ceramics Prepared From High-Energy Ball Milled Nanopowders

Recently developed (Ba0.88Ca0.12)(Ti0.94Sn0.06)O-3 (BCST) ceramic composition gained popularity as a cleaner substitute for the lead-based Pb(Zr,Ti)O-3 (PZT) after its electrical properties were found to be comparable to those of some soft-end PZTs. These properties can be further enhanced by optimizing the microstructure and phase-symmetry of the ceramic system. In the present work, BCST nanopowders have been synthesized via solid-state reaction method followed by high-energy ball milling. Initial particle size has been controlled by varying the milling speed from 100-400 rpm at fixed milling time. It has been observed that a mere change in initial particle size strongly affects the microstructural, structural and electrical properties. A monotonous decline in average particle size (similar to 97 %) with an enormous rise in the average grain size (similar to 260 %) with milling speed is observed. The increase of milling speed causes the evolution of perovskite crystal symmetry of the ceramics from orthorhombic to tetragonal, with the bulk density acquiring a peak value for BCST ceramic prepared from 175-rpm milled powder. As a consequence of relatively high density and favorable phase-structure, the piezoelectric properties of this ceramic sample exhibit a significant enhancement of about similar to 70 %.