摘要
利用低压MOCVD工艺分别在(001)取向的LaAlO3,SrTiO3和重掺杂硅单晶衬底上制备PbTiO3铁电薄膜,并通过X射线衍射谱对薄膜的微结构进行分析.X射线θ-2θ扫描显示硅衬底上得到了PbTiO3多晶薄膜,另两种衬底上得到了择优取向的PbTiO3薄膜.LaAlO3衬底上的PbTiO3薄膜有a和c两个取向,也就是薄膜中存在着90°畴结构,而生长在SrTiO3衬底上的PbTiO3薄膜中只存在c方向的择优取向.由于薄膜的尺度效应,发现c轴晶格常数与块材相比均缩短.X射线的φ扫描验证了后两类薄膜的外延特性,利用同步辐射的高强度和高能量分辨率用摇摆曲线方法研究了这两种外延薄膜的品质,进一步证明了SrTiO3衬底上的PbTiO3薄膜的单畴特性.利用重掺杂的硅衬底作底电极。
PbTiO 3 thin films were deposited on (001) redoping n Si,(001)LaAlO 3 and (001) SrTiO 3 substrates by low pressure MOCVD technique,XRD θ 2θ scan shows that the film on Si substrate has a polycrystalline structure,while the other two films have preferential orientations and their epitaxial nature was confirmed by the X ray φ scan,rocking curves of the two epitaxial thin films were taken at BSRF using the synchrotron radiation. The film on LaAlO 3 substrate has an a,c domain coexisting structure,and the film on SrTiO 3 substrate only has a c orientation. All the films exhibit a c axis shortening compare with the bulk material,and the reason can be attributed to the size effect and surface influence. The ferroelectric properties of the polycrystalline thin films were investigated using the redoping Si substrate as bottom electrode directly,and the PbTiO 3 thin film shows a perfect hysteresis loop.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1996年第10期1729-1736,共8页
Acta Physica Sinica
基金
国家高技术研究发展计划