Heteroepitaxial Growth of Nanostructured Cerium Dioxide Thin Films by MOCVD on a (001) TiO₂ Substrate

Abstract

The deposition of epitaxial CeO2 nanostructured thin films on rutile (TiO2) substrates by metal−organic chemical vapor deposition (MOCVD) has been carried out in a wide temperature range. Films have been grown on (001)TiO2 from the Ce(III) 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato diglyme adduct (Ce(hfa)3·diglyme). The X-ray diffraction patterns of all samples grown in the 450−750 °C deposition temperature range point to the formation of 〈100〉-oriented CeO2 films, whereas at higher deposition temperatures (850−1050 °C) all the deposited CeO2 films show 〈111〉 texture. fwhm rocking curves values clearly indicate that the texturing of CeO2 crystallites is greatly improved upon increasing the deposition temperature in both cases. Typical pole figure patterns demonstrate a cube-on-cube epitaxial growth in the case of 〈100〉-oriented CeO2 films, whereas 〈111〉-oriented CeO2 films show different in-plane alignments of the crystallites. A possible explanation for textural changes is proposed.

An MOCVD Approach to High‐k Praseodymium‐Based Films

“…Thus, for instance, La and Ce homologues proved to be good MOCVD precursors for the fabrication of LaAlO 3 and CeO 2 thin films on a wide variety of substrates. [60][61][62] This observation indicates an higher thermodynamic stability of the praseodymium oxyfluoride phase compared to oxides, thus pointing out the need of an alternative fluorine-free praseodymium precursor. It, therefore, transpires that the problem of unwanted fluorinated phases must be addressed case by case, depending on the metal ion nature and thermodynamic stability of the desired phase.…”

“…CeO 2 and LaAlO 3 ) thin films on a wide range of substrates. [60][61][62] Praseodymium thin-film fabrication has taken advantage of b-diketonate precursors as well as of other families including alkoxides and silylamides. [46][47][48][49] Thus, the first-gen- 3 …”

High-speed epitaxial growth of (100)-oriented CeO2 film on r-cut sapphire by laser chemical vapor deposition

“…Ceria (CeO 2 ) film is a promising candidate as buffer layer because of its small lattice mismatch with that of YBCO (less than 1%) and a thermal expansion coefficient (9.5-12.3 × 10 −6 K −1 ) between that of sapphire (8.0 × 10 −6 K −1 ) [1] and that of YBCO (12.5 × 10 −6 K −1 ) [3]. CeO 2 film is commonly prepared by metalorganic chemical vapor deposition (MOCVD) [1,[4][5][6][7]. However, the preparation of CeO 2 film by MOCVD has not been practically employed mainly due to a relatively low deposition rate (R dep ) [1,[3][4][5][6][7][8].…”

“…CeO 2 film is commonly prepared by metalorganic chemical vapor deposition (MOCVD) [1,[4][5][6][7]. However, the preparation of CeO 2 film by MOCVD has not been practically employed mainly due to a relatively low deposition rate (R dep ) [1,[3][4][5][6][7][8]. On the other hand, we reported high-speed depositions of Y 2 O 3 and CeO 2 films on polycrystalline Al 2 O 3 substrate using laser chemical vapor deposition (laser CVD) [9,10].…”

Growth of Gadolinium Oxide This Films by Liquid Injection MOCVD Using a New Gadolinium Alkoxide Precursor

“…Despite these advantages, there have been very few reports on the MOCVD of lanthanide oxides. The MOCVD of LaAlO 3 [20] and Gd 2 O 3 [21] has been reported some time ago, whilst more recent reports describe the MOCVD of Pr oxide [22] and La 2 O 3 . [23] There are also very few reports on the growth of Nd 2 O 3 by MOCVD, mainly due to the absence of suitable precursors with the appropriate stability, volatility, and decomposition characteristics.…”