Nd3+掺杂对PLZS反铁电体介电性能和储能性能的影响OA北大核心CSTPCD

Introduction Ceramic-based dielectric capacitors with a high power density are one of the most prospective energy-storage components,compared with Li-ion batteries and super-capacitors.Unfortunately,the energy-storage density of ceramic-based dielectric capacitors is one or two orders of magnitude lower than that of the batteries,which is restricted by the property of dielectric materials.Therefore,developing reliable and high-performance dielectric ceramic is a challenge in the field of dielectric capacitors.Among dielectric ceramics,antiferroelectic(AFE)material is one of the most promising candidates for energy-storage devices since they show a high maximum polarization(Pmax),low remnant polarization(Pr),and a regulated AFE-ferroelectric(FE)phase transition electric field.Recent efforts are made to enhance energy-storage properties of ceramic by component design,ion-doping and material form construct.However,a superior η is always gained at the cost of a high Wrec,becoming a challenge for synergistically achieving a ultrahigh Wrec and a superior η. Methods High-purity Pb3O4(≥95.0％,Sinopharm Chemical Reagent Co.,Ltd.,China),La2O3(≥99.9％,Sinopharm Chemical Reagent Co.,Ltd.,China),Nd2O3(>99.99％,Aladdin Biochemical Technology Co.,Ltd.,China),ZrO2(≥99.0％,Sinopharm Chemical Reagent Co.,Ltd.,China),and SnO2(≥99.5％,Sinopharm Chemical Reagent Co.,Ltd.)were used as raw materials.Pb0.98-1.5xLa0.02Ndx(Zr0.60Sn0.40)0.995O3(PL100xNZS)was selected as a basic system.Nd3+ with a small ionic radius(i.e.,1.29 Å)was introduced in PLZS to replace Pb2+(i.e.,1.49 Å)for enhancing electric filed-induced EFE-AFE.A Pb0.98-1.5xLa0.02Ndx(Zr0.60Sn0.40)0.995O3 component was designed and the ceramics were fabricated by a tape-casting method. The crystallinity,phase structure and microstructure of PL100xNZS ceramics were analyzed by an X-ray diffractometer(Rigaku Co.,Ltd.,Japan)and a model TESCAN-MIRA3 field-emission scanning electron microscope(TESCAN Co.,Czech).The dielectric properties of the PL100xNZS ceramics were measured by a computer-controlled Agilent E4980A LCR analyzer.The displace-electric field(D-E)hysteresis loops and current density-electric field curve were determined by a ferroelectric measurement system(Radiant Technologies Co.,USA).The pulsed charge-discharge behaviors were determined by a model CFD-001 resistance-inductance-capacitance(R-L-C)electric circuit(Guoguo Technology Co.,China). Results and discussion The XRD patterns show that all the samples exhibit a perovskite structure with an orthorhombic phase.The SEM images show that a dense and compact microstructure appears in PL100xNZS ceramics.The average grain size is decreased by doping of Nd3+.The dielectric behavior of PL100xNZS ceramics as a function of temperature measured at 10 kHz and 25-400℃indicates that there are three stages of dielectric constant with the increase of temperature,i.e.,the rising,the plateau and the falling regions,which correspond to the AFE,multicell cubic(MCC)and single-cell cubic(PEC)phases.The maximum polarization decreases at the same electric field,and the breakdown strength(BDS)increases with the increase of Nd3+ content due to the decreased grain size.The antiferroelectric-ferroelectric phase transition electric field(EAFE-FE)increases as the Nd3+ content increases,because of a stable antiferroelectric phase.The enhanced BDS and increased EAFE-FE imply a high energy-storage density.The recoverable energy-storage density and efficiency are critical parameters to characterize the material performance.Herein,the PL4NZS ceramic can be used as a promising energy-storage material because it exhibits a linear-like D-E loop with a large Pmax(i.e.,60 μC/cm2)and a high BDS(i.e.,490 kV/cm).A large energy storage density of 14.8 J/cm3 is obtained in PL4NZS ceramic with a high efficiency of 85％.The calculated values of Wrec and η fluctuate slightly in the range of 6.18-4.88 J/cm3 with increasing the frequency.The discharge waveforms of PL4NZS ceramic at different electric fields are investigated at room temperature with an overdamped R-L-C electric circuit.The maximum value of Wdis is 4.4 J/cm3 at 300 kV/cm,and the t0.9 is 28 ns.A large CDmax of 3 360 A/cm2 and a high PDmax of 504 MW/cm3 are achieved at 300 kV/cm in PL4NZS ceramic,indicating that the PL4NZS ceramic has a great competitiveness in high power system applications. Conclusions The high energy-storage density and efficiency were realized in designed PL100xNZS ceramics fabricated by a tape-casting technique.The effects of Nd3+ doping on the microstructure,dielectric properties,ferroelectric properties and energy storage properties of the ceramics were investigated.The Wrec was 14.8 J/cm3 with a giant η of 85％at 490 kV/cm for PL4NZS ceramic.As the temperature increases,Wrec and η of PL4NZS ceramic increased slightly.Moreover,a high Wdis of 4.4 J/cm3,a large CDmax of 3 360 A/cm2 and a high PDmax of 504 MW/cm3 were obtained in PL4NZS ceramic.It was indicated that PL4NZS ceramic could be used as a prospective dielectric material for energy-storage applications.