Large remanent polarization of (Bi, Nd)4Ti3O12 epitaxial thin films grown by metalorganic chemical vapor deposition
Large remanent polarization of (Bi, Nd)4Ti3O12 epitaxial thin films grown by metalorganic chemical vapor deposition
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DOI：
10.1063/1.1468914
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发表时间：
2002-04
影响因子：
4
通讯作者：
T. Kojima;T. Sakai;Takayuki Watanabe;H. Funakubo;K. Saito;M. Osada
中科院分区：
文献类型：
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作者：
T. Kojima;T. Sakai;Takayuki Watanabe;H. Funakubo;K. Saito;M. Osada
在（111）SrRuO 3//（111）SrTiO 3衬底上，采用金属有机化学气相沉积法在700 °C下外延生长了（104）取向的Bi 4 Ti 3 O 12、La取代的Bi 4 Ti 3 O 12 [（Bi3.44La0.56）Ti 3 O 12]和Nd取代的Bi 4 Ti 3 O 12 [（Bi3.54Nd0.46）Ti 3 O 12]薄膜。所有沉积的薄膜都表现出很强的（104）取向。（104）取向的（Bi3.54Nd0.46）Ti 3 O 12薄膜的反射极化（Pr）和矫顽场（Ec）分别为25 μC/cm 2和135 kV/cm。该Pr值大于（104）取向的（Bi3.44La0.56）Ti 3 O 12薄膜的Pr值：（Bi3.44La0.56）Ti 3 O 12薄膜的Pr和Ec值分别为17 μC/cm 2和145 kV/cm。（Bi_（3.54）Nd_（0.46））Ti_3 O_（12）薄膜具有良好的铁电性能，这是由于Nd ~（3+）的离子半径小于La ~（3+）的离子半径，Nd ~（3+）的取代使TiO_6八面体发生了较大的倾斜。此外，该Pr值几乎等于商业上使用的用于非易失性铁电随机存取存储器（Fe…
(104)-oriented Bi4Ti3O12, La-substituted Bi4Ti3O12[(Bi3.44La0.56)Ti3O12] and Nd-substituted Bi4Ti3O12[(Bi3.54Nd0.46)Ti3O12] films were epitaxially grown on (111)SrRuO3//(111)SrTiO3 substrates at 700 °C by metalorganic chemical vapor deposition. All deposited films showed strong (104) orientations. The values of the remanent polarization (Pr) and coercive field (Ec) of the (104)-oriented epitaxial (Bi3.54Nd0.46)Ti3O12 thin film were 25 μC/cm2 and 135 kV/cm, respectively. This Pr value was larger than that of the (104)-oriented (Bi3.44La0.56)Ti3O12 film: Pr and Ec values of the (Bi3.44La0.56)Ti3O12 were 17 μC/cm2 and 145 kV/cm, respectively. These good ferroelectric properties of (Bi3.54Nd0.46)Ti3O12 films can be explained by a large tilting of TiO6 octahedra induced by the substitution of Nd3+, the ionic radius of which is smaller than that of La3+. Moreover, this Pr value is almost equal to that of commercially used lead zirconate titanate (PZT) films for nonvolatile ferroelectric random access memory (Fe...