Thin films of La1âxSrxFeO3 have been prepared by the ALD (atomic layer deposition) technique using La(thd)3 (Hthd = 2,2,6,6-tetramethylheptane-3,5-dione), Sr(thd)2, Fe(thd)3, and ozone as precursors. A so-called ALD window is found in the temperature range 200 to 360 °C for LaFeO3. The effect of the pulsing procedure for the precursors on the composition of the films is examined. The results are discussed in relation to a model which ascribes differences between pulsed and obtained stoichiometries to individually different surface-area demands of the precursors. The La1âxSrxFeO3 films turned out to contain only small amounts of carbonate impurities despite the fact that films prepared from Sr(thd)2 and ozone under the same conditions contains virtually pure SrCO3. Films of La1âxSrxFeO3 have been deposited on substrates of (amorphous) soda-lime glass and single crystals of Si(100), SrTiO3(100), and LaAlO3(012). Annealed films on soda-lime glass and Si(100) substrates turned out to be polycrystalline with virtually random orientation of the crystallites. Those on MgO(100) and SrTiO3(100) substrates showed some degree of crystal orientation, whereas the annealed films on LaAlO3(012) proved to contain distinctly oriented crystallites with mosaic features.
薄膜La1-xSrxFeO3是通过原子层沉积(ALD)技术制备的,使用的前驱体包括La(thd)3(Hthd = 2,2,6,6-四甲基庚烯-3,5-二酮)、Sr(thd)2、Fe(thd)3和
臭氧。在200到360°C的温度范围内发现了所谓的ALD窗口。研究了前驱体脉冲程序对薄膜成分的影响。结果与一个模型进行了讨论,该模型将脉冲和获得的
化学计量比之间的差异归因于前驱体对表面积的不同需求。尽管在相同条件下由Sr(thd)2和
臭氧制备的薄膜几乎纯净为SrCO3,但La1-xSrxFeO3薄膜发现仅含少量
碳酸盐杂质。La1-xSrxFeO3膜已在(无定形)
钠钙玻璃和Si(100)、
SrTiO3(100)及LaAlO3(012)的单晶基底上沉积。
钠钙玻璃和Si(100)基底上的退火薄膜被发现是多晶的,晶粒呈几乎随机取向。而在MgO(100)和 (100)基底上的薄膜则显示出一定程度的晶体取向,而在LaAlO3(012)上的退火薄膜则含有具有明显取向特征的晶粒。