Microwave Assisted Synthesis and Characterization of Bismuth Layered Ferroelectric Materials

Abstract

In the present age of device miniaturization, the smart ceramics, which possess good ferroelectric and piezoelectric property, have gained substantial interest due to their application in the field of sensor, actuator, transducer, tunable capacitor and non-volatile memory devices (NvRAM s). Their operations are based on high remnant polarization (Pr), low coercive field (Ec), and high fatigue resistance. Lead zirconate titanate commonly known as PZT was the best know material to be used for NvRAM application PZT thin films usually display large remnant polarization. Nevertheless, along with these useful properties, Pb based compositions show strong toxic behaviour, which is hazardous to the human body and as well as towards the environment, thus limits its applications. This motivated the researchers to explore new lead free ferroelectrics for desired applications. A thorough literature survey shows that limited work has been carried out on these lead-free complex perovskite. newlineBismuth layer structured ferroelectrics (BSLFs) and their solid solution have gained much attention for their high value of remnant polarization and high dielectric constant. The property of BSLFs ceramic strongly depend on their crystal structure and chemical composition and sudden change in the stoichiometry by doping with proper cation and anion will drastically influence its dielectric and ferroelectric property. In view of this, we have synthesized a novel solid solution of lead-free perovskite family Strontium bismuth niobate (Sr1-xSnxBi1.95La0.05Nb2O9) and Bismuth Molybdate (Bi2Mo1-xWxO6) through the single-step microwave sintering process. Much emphasis was made on the correlation between structural and electrical properties of BSLFs. The microstructural and morphological properties were examined through Reitveld refinement, thermal analysis, and microscopy techniques like SEM and TEM. Temperature and frequency dependent dielectric properties provide the concrete evidence of diffused phase transition in all samples.