Chemical Solution Deposition of Ceria Textured Thin Films from Novel Mixed-Ligand Metal−Organic Precursors

Abstract

Novel solution precursors for CeO 2 buffer layers, based on mixed-ligand hydroxocomplexes of lanthanide acetates and nitrates with monoethanolamine (MEA) and diglyme, acting as both ligands and solvents, have been developed. The formation of mixed-ligand Ce(IV) complexes in both liquid and transparent gel precursors have been confirmed by electrospray ionization-mass spectroscopy (ESI-MS) and 1 H nuclear magnetic resonance (NMR) spectroscopy. The features of thermal decomposition of gel precursor samples were studied using thermogravimetry (TG) and differential thermogravimetry (DTG) analyses in air and in argon. The advantages of the new precursors are the accessibility of high concentrations, stability, and excellent wetting behavior of Ni-5 at.% W substrates. Various elements can be easily incorporated into them as dopants, as was shown on an example of La 3þ . Epitaxial CeO 2 and CeO 2 (La) films were deposited on Ni-W cube-textured tapes from developed solutions via the metal-organic chemical solution deposition (MOCSD) method. Incorporation of La 3þ into the buffer layer leads to improvement in the oxide's texture and the film's surface.

Tetranuclear Hydroxo Complexes of Rare-Earth Elements with the Cubane Core as Products of Self-Controlled Hydrolysis

“…Additional interest in systems of REE carboxylates with amines is also caused by their application as precursors in the solution method for the preparation of inorganic thin-film materials based on REE: oxides and fluorides [7][8][9][10]. An important advantage of these systems is a slight hydrolysis under the action of amines to form an amorphous gel providing upon annealing the homogeneity and uniformity of the formed film of inorganic material.…”

Novel mononuclear mixed ligand Ce(III) pivalate with protonated cationic form of monoethanolamine as ancillary ligand

“…In water the presence MEA acts as strong alkali like NH 3 ⋅ aq and can hydrolyze lanthanides. So, we have found that in MeCN either Ce(Acet) 3 ⋅xHAcet (HAcet = acetic acid) or mixture of Ce(NO 3 ) 3 ·6H 2 O and HAcet (1:3 molar ratio) reacted with MEA forming mixed ligand hydroxocomplexes of Ce(IV) that was confirmed by IR and 1 H NMR, electrospray MS and elemental analysis [16]. Crystals of mixed ligand compound I grown as by-product of analogous hydroxocompounds were synthesized by means of Ce(NO 3 ) 3 ·6H 2 O addition to a mixture of HPiv and MEA (3:5) in MeCN [17].…”

Fluorinated Cerium(IV) Enaminolates: Alternative Precursors for Chemical Vapor Deposition of CeO2 Thin Films

“…In more-polar solvents, the coexistence of both isomers was observed while the E:Z ratio increased with increasing polarity, reaching the maximum ratio of 63:37 in DMSO−d 6 solution. The ligands were comprehensively characterized by 13 C and 19 F NMR one-dimensional (1D) and two-dimensional (2D) experiments; the full data set and assignments are given in the Experimental Section.…”

“…9 For the preparation of ceria thin films, several physical and chemical synthetic methods have been applied, for example, gas-phase methods such as pulsed laser deposition (PLD), 10,11 metal-organic chemical vapor deposition (MOCVD), 12,13 atomic layer deposition (ALD), 14−17 or solution-based methods. 18,19 In this context, chemical vapor deposition (CVD) is a versatile coating technique, which offers decisive advantages including conformal step coverage, large deposition area, and better controllability over material properties and composition. Use of plasma-enhanced deposition (PECVD) allows film preparation under nonequilibrium conditions, usually at low temperatures, which results in film characteristics that are not obtainable by other deposition techniques.…”