The effect of thermal annealing on the properties of thin alumina films prepared by low pressure metal-organic chemical vapour deposition

Haanappel, V.A.C.; Vendel, D. van de; Corbach, H.D. van; Fransen, Τ.; Gellings, P.J.

doi:10.1016/0040-6090(95)80026-3

Cited by 10 publications

(8 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…940 cm À1 . This signal has been reported for alumina layers obtained by MOCVD on AISI 304 steel but it is not assigned to a typical AlÀO vibration [33] [40] [41]. The same band was also observed for Al 2 O 3 layers obtained by low-power oxygen discharge [42].…”

supporting

confidence: 59%

Probing Catalytic Solid-Liquid Interfaces by Attenuated Total Reflection Infrared Spectroscopy: Adsorption of Carboxylic Acids on Alumina and Titania

Ferri

Bürgi

Baiker

2002

HCA

View full text Add to dashboard Cite

Dedicated to Professor Dieter Seebach on the occasion of his 65th birthdayThe adsorption of carboxylic acids (formic, acetic, and pyruvic acid) from corresponding solutions in CH 2 Cl 2 solvent on Al 2 O 3 and TiO 2 thin films has been studied by attenuated total reflection infrared spectroscopy. The metal-oxide films were vapor-deposited on a Ge internal reflection element, which was mounted into a specially designed flow cell. The system allowed in situ monitoring of the processes occurring at the solid-liquid interface. The metal-oxide films were characterized by X-ray photoelectron spectroscopy, ellipsometry, and atomic force microscopy. Formic acid and acetic acid adsorbed predominantly as bridging species on alumina surfaces. Adsorbed free acids were not observed under a flow of neat solvent. Based on the position of the n AS (COO) and of the keto-group stretching vibration of the pyruvate ion, pyruvic acid is proposed to coordinate to the Al 2 O 3 surface in a monodentate fashion, whereas, on TiO 2 , a bidentate species is preferred. Comparison of the adsorption behavior on the vapor-deposited alumina film and on an a-Al 2 O 3 layer deposited from a water suspension of the corresponding metal-oxide powder indicated that pyruvic acid adsorbs in a similar mode, irrespective of the metal-oxide deposition technique.Introduction. ± Solid-liquid interfaces play fundamental roles in nature and technology. Many processes crucial for life occur at such interfaces and technical applications range from corrosion, tribology, electrochemistry over environmental chemistry to heterogeneous catalysis. Our knowledge of such important processes relies on techniques that probe the respective interfaces. The growing awareness that an interface may be quite different under working conditions than under conditions far away from these, has fostered the development of in situ methods. In the field of heterogeneous catalysis, important insight can be gained by monitoring the respective catalytic interface at work.Vibrational spectroscopy is ideally suited to probe interfaces [1] [2]. A vibrational spectrum contains detailed structural information of the adsorbate layer such as interaction mode between surface and adsorbate, orientation of the adsorbate and intermolecular interactions within the adsorbate layer. Furthermore, infrared radiation is noninvasive. The advances in vibrational spectroscopy of interfaces in the past few years went along with progress in instrumentation and data processing. Furthermore, the information contained in the measured spectra can now be read in more detail through comparison with calculations. The availability of sophisticated ab initio quantum-chemical programs and fast computers makes it possible to simulate spectra with predictive accuracy.

show abstract

supporting

confidence: 59%

Probing Catalytic Solid-Liquid Interfaces by Attenuated Total Reflection Infrared Spectroscopy: Adsorption of Carboxylic Acids on Alumina and Titania

Ferri

Bürgi

Baiker

2002

HCA

View full text Add to dashboard Cite

show abstract

“…To overcome this problem Jones et al generated ATI in the reactor by reacting trimethylaluminum and isopropyl alcohol in the vapor phase. [3] Besides ATI, other volatile aluminum compounds have been proposed: aluminum tri-(2-ethylhexanoate), [4] aluminum tri-(sec-butoxide), [5][6][7] aluminum (ethylacetoacetate)-di-iso-propoxide, [8] aluminum triacetylacetonate, [9][10][11][12][13] dimethyl, diethyl and di-iso-butyl aluminum acetylacetonate, [14] dimethyl aluminum isopropoxide.…”

Section: Introductionmentioning

confidence: 99%

CVD‐Fabricated Aluminum Oxide Coatings from Aluminum tri‐iso‐propoxide: Correlation Between Processing Conditions and Composition

Gleizes

Vahlas

Sovar

et al. 2007

Chemical Vapor Deposition

View full text Add to dashboard Cite

This paper presents results on aluminum oxide thin films processed using metal-organic (MO) CVD from aluminum tri-isopropoxide (ATI) without any additional oxygen source, in the temperature range 623-973 K. The films do not diffract X-rays, except when grown at 973 K or annealed at 1073 K. Their composition was investigated using several techniques; electron probe micro analysis (EPMA), energy dispersive X-ray spectroscopy (EDX), elastic recoil detection analysis (ERDA), and Rutherford back-scattering spectroscopy (RBS). It corresponds to the formula AlO(OH) for those grown at 623 K. The composition of films prepared above 688 K corresponds to the formula Al 2 O 3 . Between 623 K and 688 K, partly hydroxylated films are obtained. This is confirmed by Fourier transform infrared (FTIR) transmission spectroscopy (no OH absorption band in the 3500 cm -1 region for films prepared above 688 K), and by thermogravimetric analysis (TGA, DTG) (no significant mass loss for films prepared above 688 K). Observations using the transmission electron microscopy (TEM) showed that films prepared at 623 K are amorphous, while those prepared at 973 K are nanocrystalline. In both cases, c-Al 2 O 3 crystals are formed and progressively grow on exposure to the TEM electron beam. Knowing the correlation between processing conditions and the composition of such films should help optimize the process with regards to any aimed property of use.

show abstract

“…1), a two-layered interface structure with varying layer thickness and density of functional groups is considered. Al2O3 particles typically comprise surficial OH groups; selected pre-treatment or activation steps increase the number of OH groups on the surface, while thermal annealing decreases the OH density due to condensation reactions between adjacent OH groups [20][21]. In the current study, the Al2O3 nanoparticles were neither pre-treated nor thermally annealed.…”

Section: A Structural Models Of the Interfacementioning

confidence: 88%

Structural Model for the Estimation of the Equivalent Permittivity of Nanodielectrics Based on Polyethylene and Epoxy Resins

et al. 2021

View full text Add to dashboard Cite

A structural model has been developed in order to calculate the equivalent permittivity of nanocomposites based on low-density polyethylene (LDPE) and epoxy resins (ERs) with inorganic fillers. It was assumed that each nanoparticle was centered in an interfacial region composed of three layers in the case of LDPE-based nanocomposites, and of two layers in the case of ER-based nanocomposites. The model for the estimation of the permittivity has been designed for flat samples of the height g, divided into cubes with the side-length l. Each of these cubes contains eight nanoparticles, which are separated from the polymer matrix by two or three layers. Based on the types and concentrations of dipoles present in the layers, the relative permittivity of each layer of the interface can be calculated. By the employment of a 3D numerical model in COMSOL, implemented by the finite element method associated with a cube, the distribution of the electric field inside a cube can be determined, which yields the values of the equivalent permittivity of the nanocomposites. In order to verify the numerical results, the permittivity of the nanocomposites based on LDPE and ERs with inorganic nanofillers (SiO2 or Al2O3) was determined in laboratory experiments. The results reveal congruent correlation between the computed and the experimentally determined values of the equivalent permittivity of the nanodielectrics.

show abstract

The effect of thermal annealing on the properties of thin alumina films prepared by low pressure metal-organic chemical vapour deposition

Cited by 10 publications

References 16 publications

Probing Catalytic Solid-Liquid Interfaces by Attenuated Total Reflection Infrared Spectroscopy: Adsorption of Carboxylic Acids on Alumina and Titania

Probing Catalytic Solid-Liquid Interfaces by Attenuated Total Reflection Infrared Spectroscopy: Adsorption of Carboxylic Acids on Alumina and Titania

CVD‐Fabricated Aluminum Oxide Coatings from Aluminum tri‐iso‐propoxide: Correlation Between Processing Conditions and Composition

Structural Model for the Estimation of the Equivalent Permittivity of Nanodielectrics Based on Polyethylene and Epoxy Resins

Contact Info

Product

Resources

About