Ferroelectric and piezoelectric properties of novel relaxor ferroelectric single crystals PMNT
Ferroelectric and piezoelectric properties of novel relaxor ferroelectric single crystals PMNT
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DOI：
10.1007/bf02887091
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发表时间：
2000-03
影响因子：
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通讯作者：
Guisheng Xu;Haosu Luo;P. Wang;Haiqing Xu;Z. Yin
中科院分区：
文献类型：
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作者：
Guisheng Xu;Haosu Luo;P. Wang;Haiqing Xu;Z. Yin
用改进的Bridgman法生长了尺寸为40 mm × 80 mm的弛豫铁电单晶PMNT，并对其铁电和压电性能进行了表征。其性能随组成和切割类型而变化。在（001）切面上，PMNT 76/24单晶的介电常数ε = 3400，介电损耗tanδ <0.7%，压电常数d33 = 980 pC/N，机电耦合系数kt = 0.55，Tc = 110°C。而（001）切面的PMNT 67/33单晶性能较好：ε约为5 300，tanδ <0. 6%，d33可达3 000 pC/N，kt 0. 64，k330. 93，Tc约为150°C。其他切口如（110）和（111）的压电性能远低于（001）切口。用该方法生长的菱方体PMNT晶体比高温溶液法生长的晶体具有更好的压电性能，其k值比菱方体PZNT单晶高。研究还发现，铁电和压电性能的波动与成分均匀性和极化程度等因素有关。
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 ∈ of about 3 400, a dielectric loss of tanδ <0.7%, a piezoelectric constantd33of 980 pC/N, an electromechanical coupling factorktof 0.55 andTcof about 110°C. Whereas the properties of PMNT67/33 single crystals on (001) cut were better:∈of about 5 300, tanδ <0.6%, d33up to 3 000 pC/N,kt0.64, k330.93 and Tcof 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 ktthan 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.