Dielectric and piezoelectric perfomance of lead-free ceramics of boron sodium gadolinate niobate at morphotropic phase boundary  

作　　者：Nissamuddeen Kunnath Jacob Philip 

机构地区：[1]Department of Instrumentation Cochin University of Science and Technology Cochin 682022,India [2]Department of Physics PSMO College Tirurangadi Malappuram 676306,India [3]Amal Jyothi College of Engineering Kanjirappally,Kottayam 686518,India

出　　处：《Journal of Advanced Dielectrics》2020年第4期38-46,共9页先进电介质学报（英文）

摘　　要：New lead-free piezoceramic nanocomposites of Boron Sodium Gadolinium Niobate(BNGN),with general formula(1-x)B_(0.5)Na_(0.5)GdO3xB_(0.5)Na_(0.5)NbO_(3),exhibiting a Morphotropic Phase Boundary(MPB),have been synthesized following hydrothermal method followed by solid state sintering.The occurrence of MPB at the composition with x=0.55,at which rhombohedral and monoclinic phases are found to coexist,has been confirmed using powder XRD.This accounts for the occurrence of large remnant polarization when the sintered ceramic pellets are subjected to electric poling at 2KV/mm.Uniform microstructure of various compositions is confirmed by SEM imaging.Dielectric and piezoelectric properties of the samples are found to be comparable to those of commercial grade PZT.At the MPB,the d_(33)coefficient is found to be 556 pC/N,which is close to that of commercial grade PZT,which makes BNGN a promising material to substitute lead containing PZT in the near future.

关 键 词：Piezoceramic nanocomposites morphotropic phase boundary Boron Sodium Gadolinium Niobate lead-free ceramics piezoelectric strain coefficient rhombohedral-monoclinic phase boundary 

分 类 号：TQ1[化学工程]