Effective piezoelectric properties,electromechanical coupling factors(ECF)and figures of merit(FOM)are studied in leadfree 0-3-type composites based on novel ferroelectric 0.965(K_(0.48)Na_(0.52))(Nb_(0.96)Sb_(0.04))O...Effective piezoelectric properties,electromechanical coupling factors(ECF)and figures of merit(FOM)are studied in leadfree 0-3-type composites based on novel ferroelectric 0.965(K_(0.48)Na_(0.52))(Nb_(0.96)Sb_(0.04))O_(3)-0.035Bi_(0.5)Na_(0.5)Zr_(0.15)Hf_(0.75)O_(3) ceramic.Systems of prolate ceramic inclusions are surrounded by a large polymer matrix that can be either monolithic(in the 0-3 composite)or porous(in the 0-3-0 composite).Non-monotonic volume-fraction dependences of the effective piezoelectric coefficients g_(3j)^(*),ECF k_(3j)^(*),squared FOM d_(3j)^(*)g_(3j)^(*)and their modified analogs for stress-driven systems are analysed,and examples of the high longitudinal piezoelectric sensitivity(g33^(*)>100 mV.m/N)are considered.A role of microgeometrical factors,that promote the large effective parameters and anisotropy of properties in the 0-3-type composites,is highlighted.New“aspect ratio-volume fraction”diagrams are first built to describe conditions for high piezoelectric sensitivity,large modified FOM and their anisotropy in the studied composites.These advanced materials can be of value for piezoelectric sensor,energy-harvesting and related applications.展开更多
文摘Effective piezoelectric properties,electromechanical coupling factors(ECF)and figures of merit(FOM)are studied in leadfree 0-3-type composites based on novel ferroelectric 0.965(K_(0.48)Na_(0.52))(Nb_(0.96)Sb_(0.04))O_(3)-0.035Bi_(0.5)Na_(0.5)Zr_(0.15)Hf_(0.75)O_(3) ceramic.Systems of prolate ceramic inclusions are surrounded by a large polymer matrix that can be either monolithic(in the 0-3 composite)or porous(in the 0-3-0 composite).Non-monotonic volume-fraction dependences of the effective piezoelectric coefficients g_(3j)^(*),ECF k_(3j)^(*),squared FOM d_(3j)^(*)g_(3j)^(*)and their modified analogs for stress-driven systems are analysed,and examples of the high longitudinal piezoelectric sensitivity(g33^(*)>100 mV.m/N)are considered.A role of microgeometrical factors,that promote the large effective parameters and anisotropy of properties in the 0-3-type composites,is highlighted.New“aspect ratio-volume fraction”diagrams are first built to describe conditions for high piezoelectric sensitivity,large modified FOM and their anisotropy in the studied composites.These advanced materials can be of value for piezoelectric sensor,energy-harvesting and related applications.
