Improving mechanical quality factor Q_(m) is of great significance for high-power applications.Here,a new strategy of the[111]_(c) texture engineering was proposed to enhance the performances of high-power piezoelectr...Improving mechanical quality factor Q_(m) is of great significance for high-power applications.Here,a new strategy of the[111]_(c) texture engineering was proposed to enhance the performances of high-power piezoelectric ceramics.The 5 vol%BaTiO_(3)(BT)templates with the[111]c preferred orientation were in-troduced into matrix powders of 0.03 Pb(Mn_(1/3) Nb_(2/3))O_(3)-0.33Pb(Ni_(1/3) Nb_(2/3))O_(3)-0.28 PbZrO_(3)-0.36PbTiO_(3)(28PZ(R))to form the[111]c textured ceramics(28PZ(T)),possessing a texture degree of 74%.The mul-tiple of uniform density in EBSD increased from 0.63 in randomly oriented 28 PZ(R)to 6.63 in 28PZ(T).The good lattice matching between BT templates and textured grains was observed using high-resolution transmission electron microscopy,confirming the microscopic origin of the[111]c texture.The maximum phase angleθmax of 88.2°was quite near 90°in 28PZ(T),ensuring the optimal Qm value of 1275 and the great figure of merit of 255,000 pC/N.The increased Q_(m) in[111]c texture ceramics was confirmed due to the reduced intrinsic polarization directions rather than the pinning effect of the internal bias field.Larger grain sizes with larger domains restrained the movement of domain walls in 28 PZ(T),which was also favorable to higher Q_(m).This work may provide a new promising route for further high-power applications.展开更多
Textured BaTiO_(3)(BT)-based lead-free ceramics have gained significant attention due to their high piezoelectric coefficient(d)and very large field induced strain(S).However,costly nano-size raw materials,excessively...Textured BaTiO_(3)(BT)-based lead-free ceramics have gained significant attention due to their high piezoelectric coefficient(d)and very large field induced strain(S).However,costly nano-size raw materials,excessively high sintering temperature and low Curie temperature(T_(c))hinder their device applications.In this work,highly[001]_(c)-oriented(Ba_(0.95)Ca_(0.05))(Zr_(0.04)Ti_(0.96))O_(3) ceramics with x mol%CuO(x=0.25,0.5,1.0,2.5)denoted as BCZT-x were synthesized by templated grain growth using micro-sized raw powders.The introduction of CuO sintering agent lowered the sintering temperature by 125℃ to 1450℃,and the BCZT-1.0 achieved a high texture degree of∼99%.In addition,the CuO-based liquid phases eliminated boundaries between BT templates and BCZT matrix powders.Such liquid-phase sintering reduced sintering stresses,decreased the average grain size of BCZT-1.0 from 16μm down to 13μm,and increased the dielectric dispersion coefficientγto 1.63.The almost smoothed out T_(O-T) anomaly in the temperature dependence of dielectric permittivity and comparably high T_(c)(>102℃)lead to better temperature stability.The narrower grain orientation distribution with full width at half maximum(FWHM)of∼5.9°and smaller domains with the size of 0.1–0.5μm in width and 3–8μm in length were obtained,a high field induced maximum strain S_(max) of 0.38%and low H_(s) of 5.2%have been achieved in BCZT-1.0 textured ceramics together with a high and homogeneous piezoelectric stress coefficient d_(33)∼780 pC/N and very large d_(33)∗∼2950 pm/V.展开更多
Piezoelectric multilayer actuators(MLAs)possess unique advantages of lower driving voltages and more compact structures than bulk ceramic actuators.However,the internal electrode layers in MLAs inevitably weaken the o...Piezoelectric multilayer actuators(MLAs)possess unique advantages of lower driving voltages and more compact structures than bulk ceramic actuators.However,the internal electrode layers in MLAs inevitably weaken the output and result in relatively lower strain.The hysteresis property of piezoelectric ceramics also significantly limits the positioning accuracy of MLAs.In this work,we adopted a synergistic strategy of crystallographic texturing and domain engineering in BaTiO_(3)-based MLAs to enhance strains by improving piezoelectricity while simultaneously restraining the ultra-low hysteresis.We prepared[001]c-oriented(Ba_(0.95)Ca_(0.05))(Ti_(0.94)Zr_(0.005)5Sn_(0.05))O_(3)(BCTZS)ceramic layers in MLAs through the template grain growth(TGG)method with a texture degree of~95%.The textured BCTZS MLAs had a large displacement of 196 nm at 200 V(~2.4 times that of randomly oriented ones)and achieved ultra-low strain hysteresis(Hs<9%).These almost identical displacement and strain hysteresis in textured MLAs before and after polarization at 200 V indicated better positioning repeatability under various voltage experiences.This finding can be attributed to easier domain switchings,because the high texture degree and the dominant“4O”domain configurations in textured grains accommodated the clamping stress,which decreased the domain wall energy but increased the domain flexibility.展开更多
基金supported by the Natural Science Foundation of Heilongjiang Province(No.LH2021E052)the National Natural Science Foundation of China(Grant Nos.52202131 and 52002093)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.HIT.NSRIF202313 and HIT.NSRIF202214)the National Key Research and Development Program of China(No.2022YFB3403902).
文摘Improving mechanical quality factor Q_(m) is of great significance for high-power applications.Here,a new strategy of the[111]_(c) texture engineering was proposed to enhance the performances of high-power piezoelectric ceramics.The 5 vol%BaTiO_(3)(BT)templates with the[111]c preferred orientation were in-troduced into matrix powders of 0.03 Pb(Mn_(1/3) Nb_(2/3))O_(3)-0.33Pb(Ni_(1/3) Nb_(2/3))O_(3)-0.28 PbZrO_(3)-0.36PbTiO_(3)(28PZ(R))to form the[111]c textured ceramics(28PZ(T)),possessing a texture degree of 74%.The mul-tiple of uniform density in EBSD increased from 0.63 in randomly oriented 28 PZ(R)to 6.63 in 28PZ(T).The good lattice matching between BT templates and textured grains was observed using high-resolution transmission electron microscopy,confirming the microscopic origin of the[111]c texture.The maximum phase angleθmax of 88.2°was quite near 90°in 28PZ(T),ensuring the optimal Qm value of 1275 and the great figure of merit of 255,000 pC/N.The increased Q_(m) in[111]c texture ceramics was confirmed due to the reduced intrinsic polarization directions rather than the pinning effect of the internal bias field.Larger grain sizes with larger domains restrained the movement of domain walls in 28 PZ(T),which was also favorable to higher Q_(m).This work may provide a new promising route for further high-power applications.
基金This work was supported by the Postdoctoral Science Foundation(Nos.BX20490103,2020M681089,LBH-Z19065 and LBHZ13109)the National Natural Science Foundation of China(No.52002093).
文摘Textured BaTiO_(3)(BT)-based lead-free ceramics have gained significant attention due to their high piezoelectric coefficient(d)and very large field induced strain(S).However,costly nano-size raw materials,excessively high sintering temperature and low Curie temperature(T_(c))hinder their device applications.In this work,highly[001]_(c)-oriented(Ba_(0.95)Ca_(0.05))(Zr_(0.04)Ti_(0.96))O_(3) ceramics with x mol%CuO(x=0.25,0.5,1.0,2.5)denoted as BCZT-x were synthesized by templated grain growth using micro-sized raw powders.The introduction of CuO sintering agent lowered the sintering temperature by 125℃ to 1450℃,and the BCZT-1.0 achieved a high texture degree of∼99%.In addition,the CuO-based liquid phases eliminated boundaries between BT templates and BCZT matrix powders.Such liquid-phase sintering reduced sintering stresses,decreased the average grain size of BCZT-1.0 from 16μm down to 13μm,and increased the dielectric dispersion coefficientγto 1.63.The almost smoothed out T_(O-T) anomaly in the temperature dependence of dielectric permittivity and comparably high T_(c)(>102℃)lead to better temperature stability.The narrower grain orientation distribution with full width at half maximum(FWHM)of∼5.9°and smaller domains with the size of 0.1–0.5μm in width and 3–8μm in length were obtained,a high field induced maximum strain S_(max) of 0.38%and low H_(s) of 5.2%have been achieved in BCZT-1.0 textured ceramics together with a high and homogeneous piezoelectric stress coefficient d_(33)∼780 pC/N and very large d_(33)∗∼2950 pm/V.
基金supported by Natural Science Foundation of Heilongjiang Province(LH2022E049)National Natural Science Foundation of China(Grant no.52202131,52002093)+2 种基金National Postdoctoral Program for Innovative Talents(Grant nos.BX20190103)Guangdong Basic and Applied Basic Research Foundation(2022A1515110498)National Key Research and Development Program of China(No.2022YFB3403902).
文摘Piezoelectric multilayer actuators(MLAs)possess unique advantages of lower driving voltages and more compact structures than bulk ceramic actuators.However,the internal electrode layers in MLAs inevitably weaken the output and result in relatively lower strain.The hysteresis property of piezoelectric ceramics also significantly limits the positioning accuracy of MLAs.In this work,we adopted a synergistic strategy of crystallographic texturing and domain engineering in BaTiO_(3)-based MLAs to enhance strains by improving piezoelectricity while simultaneously restraining the ultra-low hysteresis.We prepared[001]c-oriented(Ba_(0.95)Ca_(0.05))(Ti_(0.94)Zr_(0.005)5Sn_(0.05))O_(3)(BCTZS)ceramic layers in MLAs through the template grain growth(TGG)method with a texture degree of~95%.The textured BCTZS MLAs had a large displacement of 196 nm at 200 V(~2.4 times that of randomly oriented ones)and achieved ultra-low strain hysteresis(Hs<9%).These almost identical displacement and strain hysteresis in textured MLAs before and after polarization at 200 V indicated better positioning repeatability under various voltage experiences.This finding can be attributed to easier domain switchings,because the high texture degree and the dominant“4O”domain configurations in textured grains accommodated the clamping stress,which decreased the domain wall energy but increased the domain flexibility.
