Ferroelectric and piezoelectric properties of novel relaxor ferroelectric single crystals PMNT  

作　　者：XU Guisheng LUO Haosu WANG Pingchu XU Haiqing YIN Zhiwen 

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

出　　处：《Chinese Science Bulletin》2000年第6期491-495,共5页

摘　　要：Relaxor ferroelectric single crystals PMNT with the size of φ40 mm×80 mm have been grown by a modified Bridgman method and their ferroelectric and piezoelectric properties have been characterized. The properties varied with the compositions and cut types. On the (001) cut, PMNT76/24 single crystals exhibited a dielectric constant ε of about 3 400, a dielectric loss of tanδ 【0.7%, a piezoelectric constant d33 of 980 pC/N, an electromechanical coupling factor kt of 0.55 and Tc of about 110℃. whereas the properties of PMNT67/33 single crystals on (001) cut were betler: e of about 5 300, tan5 【0.6%, d33 up to 3 000 pC/N, kt 0.64, K33 0.93 and Tc of about 150℃. The piezoelectric properties on other cuts such as (110) and (111) were much lower than those on the (001) cut. The rhombohedral PMNT crystals grown by this method showed more excellent piezoelectric properties than those grown by high temperature solution method and higher value of kt than the rhombohedral PZNT single crystals. it has alsoRelaxor ferroelectric single crystals PMNT with the size of ?40 mm × 80 mm have been grown by a modified Bridgman method and their ferroelectric and piezoelectric properties have been characterized. The properties varied with the compositions and cut types. On the (001) cut, PMNT76/24 single crystals exhibited a dielectric constant ∈ of about 3 400, a dielectric loss of tanδ <0.7%, a piezoelectric constantd 33 of 980 pC/N, an electromechanical coupling factork t of 0.55 andT c of about 110°C. Whereas the properties of PMNT67/33 single crystals on (001) cut were better:∈ of about 5 300, tanδ <0.6%, d33 up to 3 000 pC/N,k t 0.64, k33 0.93 and Tc of about 150°C. The piezoelectric properties on other cuts such as (110) and (111) were much lower than those on the (001) cut. The rhombohedral PMNT crystals grown by this method showed more excellent piezoelectric properties than those grown by high temperature solution method and higher value of kt than the rhombohedral PZNT single crystals. It has also been found that the fluctuation in ferroelectric and piezoelectric properties was related to such factors as composition uniformity and poling degree.

关 键 词：relaxor FERROELECTRICS single crystals PMNT PIEZOELECTRIC PROPERTIES FERROELECTRIC properties. 

分 类 号：O78[理学—晶体学]