Antiferroelectric-ferroelectric (AFE-FE) phase transition in ceramic Pb 0.97 La 0.02 (Zr 0.75 Sn 0.136 Ti 0.114)O 3 (PLZST) was studied by dielectric spectroscopy as functions of frequency (10 2-10 5 Hz) and pressure (0-500 MPa) under a DC electric field.The hydrostatic pressure-dependent remnant polarization and dielectric constant were measured.The results show that remnant polarization of the metastable rhombohedral ferroelectric PLZST poled ceramic decreases sharply and depoles completely at phase transition under hydrostatic pressure.The dielectric constant undergoes an abrupt jump twice during a load and unload cycle under an electric field.The two abrupt jumps correspond to two phase transitions,FE-AFE and AFE-FE.
Bulk crystals of high Curie temperature(T_(C))24Pb(In_(1/2(Nb_(1/2))O_(3)-43Pb(Mg_(1/3)Nb_(2/3))O_(3)-33PbTiO_(3)(24PIN-43PMN-33PT)with 55 mm in diameter and 130mm in length were reproducibly grown by the bottom-seeded Bridgman method.The X-ray diffraction(XRD)spectrum indicated that the as-grown crystal was a single phase with rthombohedral structure at room temperature,the domain morphology and the phase transition sequence of R→T→C were observed,the full width at half maximum(FWHM)of X-ray rocking curve of(002)face was about 0.77°,and the defect density was inferred to 2.56×10^(10)cm^(-2).The measured density of the as-grown crystals was very close to the theoretical one.Variation of the transition temperature of the as-grown crystals along the growth direction revealed that T_(C) increased linearly along the growth direction and rthombohedral to tetrahedral phase transition temperature(T_(RT))gradually decreased in the middle part of the ingot.
Linghang WangZhuo XuZhenrong LiYuhui WanJunjie GaoFei Li
This paper investigates the pyroelectric of poled antiferroelectric (AFE) ceramic Pb 0.97 La 0.02 (Zr 0.69 Sn 0.196 Ti 0.114)O 3 and its remnant polarization dependence of hydrostatic pressure.The results show that the bound charges of poled sample can be released in short time by temperature field or pressure field.The released charge abruptly forms a large pulse current.The phenomena of released charge under external fields result in the ferroelectric-AFE phase transition induced by temperature or hydrostatic pressure.
