| Lead zirconate stannate titanate(PZT)-based ceramics is a kind of important information function material. It has excellent piezoelectric, ferroelectric, pyroelectric performance, which is widely used in electronic info rmation, mobile communications, energy, technology, national defense and other modern high-tech fields. A variety of performance of PZT-based ceramics is closely related to the phase transition behavior in the field, temperature and stress, so the research of the structure and phase transition behavior play an important role in understanding its physical properties and microscopic mechanisms, which also has important theoretical guiding significance for the development of new materials and devices. Especially,the Sn4+ partly replac ing(Zr, Ti)4+ to obtain the zirconium stannate titanium lead-based ceramics has widen area of the antiferroelectric phase. It becomes one of the preferred materials for the study of ferroelectric/antiferroelectric phase structure, phase transformation theory and the development of a variety of applications such as energy conversion. In recent years, doping Pb(Zr0.42Sn0.4Ti0.18)O3 ceramics was found to have a good performance in many aspects.Based on the above background,dielectric, ferroelectric, energy storage and pyroelectricity performance of a wide range of different phas e structure of ceramics were studied by changing the Zr:Sn and Sn:Ti. The effect of composition and temperature on the phase transformation was investigated. The ferroelectric/ferroelectric phase boundary was determined and scaling behavior of ferroelectric and antiferroelectric dynamic electric hysteresis under the action of temperature and electric field was studied. The main conclusions are as follows:(1) Pb0.97La0.02(Zr0.12+xSn0.7- xTi0.18)O3 ceramics are present typical ferroelectric electric hysteresis loop. With the increase of Zr content, Curie temperature of ceramics gradually increase and dielectric constant begin to rise slowly thenincrease dramatically. With the temperature increas ing, PLZST12/70/18 、PLZST52/30/18 and PLZST62/20/18 ceramics changes from ferroelectric to paraelectric phase, while PLZST22/60/18 、 PLZST32/50/18 and PLZST42/40/18 experiences from ferroelectric to antiferroelectric to paraelectric phase transitions. The PLZST32/50/18 and PLZST42/40/18 ceramics both have high pyroelectric coefficient.(2) With a decrease in Ti content, the dielectric constant of Pb0.97La0.02(Zr0.42Sn0.1+xTi0.48- x)O3 ceramics gradually decreased and Curie temperature firstly decreases then increases. PLZST42/10/48, PLZST42/20/38, PLZST42/30/28, PLZST42/42/16, PLZST42/43/15 show the typical ferroelectric hysteresis loops, while PLZST42/44/14, PLZST42/45/13, PLZST42/46/12, PLZST42/47/11 show the typical antiferroelectric hysteresis loop. When the content of Zr is 0.42, the phase boundary of ferroelectric/antiferroelectric locates at Ti content between 0.14 and 0.15. Induced ferroelectric phase is not stable which is easy to become antiferroelectric phase. With the increase of temperature, the higher electric field is needed to stabilize ferroelectric phase leading to higher EF and EA. ?E=(EF-EA) represents the stability of ferroelectric phase.(3) Pb1-3x/2Lax(Zr0.42Sn0.47Ti0.11)O3 ceramics have the pure perovskite structure. With the increase of La content, Curie temperature decreases, and dielectric constant first decreases and then increases. When the La content is 2%, energy storage density is the highest.(4) Dynamic scaling behavior of the Pb0.97La0.02(Zr0.42Sn0.45Ti0.13)O3 ceramics follow the formula of <A> ∝f0.034(E0-27.8)0.3. The frequency and electric field dependence are weak. A set of simple linear temperature scaling relations of Pb0.97La0.02(Zr0.42Sn0.3Ti0.28)O3 ceramics are established for Ec and <A>. The highest scaling applicative temperature is over Tc, suggesting that it may be attributed to thermal stability dependent on grain size or the retention of the ferroelectric phase during the switching process or the effects of field induced phase transition. |
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