SrBi_4Ti_4O_(15)薄膜的溶胶凝胶制备及其生长行为(英文)

PREPARATION AND GROWTH BEHAVIOR OF SrBi_4Ti_4O_(15) FERROELECTRIC THIN FILMS BY SOL-GEL METHOD

以氯化锶、硝酸铋和钛酸丁酯为原料,柠檬酸为络合剂,配制了稳定的SrBi4Ti4O15(SBTi)前驱液。采用层层快速退火工艺,在Pt/Ti/SiO2/Si基片上制备了a轴取向增强的SBTi铁电薄膜,通过场发射扫描电镜、环境扫描电镜及X射线衍射等微观分析手段研究了保温时间和成膜次数对薄膜结晶性、微观结构和生长行为的影响。结果表明:层层快速退火工艺,可有效抑制焦绿石相的形成。随着退火时间的延长,薄膜的结晶性变好;但退火时间延长到30 min以上,薄膜的结晶性变差。由于SBTi晶体生长的各向异性及单层膜厚对晶体沿[119]方向生长的限制,随着涂覆次数的增加,SBTi薄膜(119)峰和(200)峰的强度逐渐增大,而(00l)峰的强度反而略有减少,从而使I(200)/I(119)、I(200)/I(0010)、I(119)/I(0010)逐渐增大。

A stable strontium bismuth titanate （SBTi） precursor solution was prepared using strontium chloride, bismuth nitrate, and tetrabulyl titanate as raw materials, and citric acid as a complex agent. SBTi thin films with enhanced a-axis orientation were prepared on Pt/Ti/SiO2/Si substrate by a layer-by-layer rapid annealing method. With the aids of field emission scanning electron microscopy, environmental scanning electron microscopy and X-ray diffraction, the effects of annealing time and number of coatings on the crystallization and the growth behavior of the SBTi thin films were investigated. The results indicate that the pyrochlore phase is restrained successfully by the layer-by-layer rapid thermal annealing method. The crystallization of the film is enhanced with the increase of annealing time; however, it is weakened when the annealing time is more then 30 min.Because of the anisotropic growth of SBTi crystals and the restriction of growth in the [119] direction by the thickness of a single-annealed layer, the intensity of the （200） and （119） peaks increase with the increase of the number of coating layers, and the former peak increases more quickly. However, the intensity of the （00l） peak decreases with the increase of the number of layers, so the relative intensities of the （200） I（200）/I（119）, I（200）/I（0010）] and （119） [I（119）/I（0010）] peaks increase with the increase of the number of layers.