Ferroelectric phase transition in relaxor ferroelectric single crystals 0.76PMN-0.24PT  

作　　者：XU Guisheng LUO Haosu WANG Pingchu Ql Zhenyi YIN Zhiwen 

机构地区：[1]Laboratory of Functional Inorganic Materials,Shanghai Institue of Ceramics,Chinese Academy of Sciences,Shanghai 201800,China [2]Xiangtan Polytechnic University,Xiangtan 411201,China

出　　处：《Chinese Science Bulletin》2000年第15期1380-1385,共6页

摘　　要：The features of the single crystals 0.76PMN-0.24PT in dielectric, ferroelectric, pyroelectric properties and domain structures indicate that they are located between typical ferroelectrics and normal ones. The unpoled crystals present a transitional domain configuration between microdomains and typical macrodomains while the crystals on (001) cuts undergo field-induced phase transition under poling, showing two special temperature points Td and Tm during the succedent heating procedure. The dielectric constant starts to decrease drastically at Td during cooling, or the transformation from induced macrodomain to transitional domain takes place at Td during heating. Ferroelectric-paraelectric phase transition or depolarization continues within the whole temperature range of Td-Tm, where ferroelectric phase in the form of transitional macrodomains coexists with paraelectric phase. Then the crystals macroscopically transoform into paraelectric phase containing ferroelectric microdomains at a temperatureThe features of the single crystals 0.76PMN-0.24PT in dietectric, ferroetectric, pyroetectric properties and domain structures indicate that they are located between typical ferroetectrics and normal ones. The unpoled crystals present a transitional domain configuration between microdomains and typical macrodomains while the crystals on (001) cuts undergo fietd-induced phase transition under poling, showing two special temperature points Td andT m during the succedent heating procedure. The dietectric constant starts to decrease drastically at Td during cooling, or the transformation from induced macrodomain to transitional domain takes place atT d during heating. Ferroetectric-paraetectric phase transition or depolarization continues within the whole temperature range ofT d-T m, where ferroetectric phase in the form of transitional macrodomains coexists with paraetectric phase. Then the crystals macroscopically transoform into paraetectric phase containing ferroetectric microdomains at a temperature aboveT m. However, owing to the influence of crystallite orientation on fietd-induced phase transition, the temperatureT d does not appear in the same temperature-etectric fietd history in multicrystal ceramics with the same composition as the above single crystals.

关 键 词：relaxor FERROELECTRICS single CRYSTALS FERROELECTRIC phase transition DOMAIN structure PMNT. 

分 类 号：O482.4[理学—固体物理]