Henry J. Gysling

Preparation of zinc sulfide thin films by ultrasonic spray pyrolsis from bis(diethyldithiocarbamato) zinc(II)

Abstract Thin films of zinc sulfide were prepared by ultrasonically spraying a toluene solution of bis(diethyldithiocarbamato)zinc(II) onto silicon, sapphire and gallium arsenide substrates at 460–520 °C. The films prepared on silicon or sapphire were found to have a highly oriented hexagonal structure, while those deposited onto cubic (100) gallium arsenide showed a highly oriented cubic structure. The films were characterized by X-ray diffraction analysis, ellipsometry, scanning electron microscopy, and IR spectroscopy.

Epitaxial growth of lithium niobate thin films from a single‐source organometallic precursor using metalorganic chemical vapor deposition

Lithium niobate thin films were deposited on (0001) sapphire using metalorganic chemical vapor deposition. An organometallic compound, formed by reaction of lithium dipivaloylmethanate and niobium(V) ethoxide, was used as a single‐source precursor. The epitaxial nature of the films was established by x‐ray diffraction and Rutherford backscattering analyses (RBS).

Organotellurium(IV) complexes: synthesis and molecular structure of 2,6-diacetylpyridine (C,N,O) tellurium(IV) trichloride

Abstract The reaction of TeCl4 with 2,6-diacetylpyridine in methylene chloride or tetrahydrofuran gives a new type of organotellurium (IV) compound. An X-ray structure determination showed that the organic radical bonds to the tellurium as a tridentate ligand via a methylene carbon of one of the acetyl groups, the pyridine nitrogen, and the carbonyl oxygen of the second acetyl group. Analogous organotellurium trichloride complexes involving C,O coordination have been formulated for the condensation products of TeCl4 with 2-acetylcyclohexanone and 3-acetyl-7-methoxycoumarin, while C,N coordination occurs in the condensation product of TeCl4 and 2-acetylpyridine.

Synthesis and properties of tellurium(II) compounds: Diaryltelluroesters, ArCOTeAr′

Abstract A series of organotellurium(II) derivatives of the general formula ArCOTeAr′ (Ar,Ar′ = phenyl, p-tolyl, p-anisyl, p-bromophenyl, p-trifluoromethylphenyl, 1-naphtyl) have been prepared and characterized chemically and spectroscopically. Various chemical reactions of this class of compounds have been investigated, and the reaction of these compounds with (PhCN) 2 PdCl 2 to give the polymeric (Pd(TeAr′) 2 ) n derivatives suggests that these organotellurium reagents may be useful precursors of TeAr′ − ligands in reactions with transition-metal substrates.

125Te NMR spectra of tellurium heterocycles

Abstract The 125Te chemical shifts and 125Te-1H coupling constants for the heterocycle 1,3-dihydrobenzo[c]tellurophene and its dihalo oxidation products have been measured and shown to correlate with the oxidation state of the tellurium and the electronegativity of the halo substituent. Halogen exchange in mixed dihalides has also been monitored by 125Te NMR. Examination of typical Te-compounds in the oxidation states −II, +II and +IV reveals a chemical shift range of 3,500 ppm.

Solid‐phase epitaxial growth of lithium tantalate thin films deposited by spray‐metalorganic chemical vapor deposition

We demonstrate the solid‐phase epitaxial crystallization of thin films of lithium tantalate deposited on lithium niobate and sapphire substrates. An organometallic compound, formed by reaction of lithium dipivaloylmethanate and tantalum(V) ethoxide, is used as a single‐source precursor for the deposition of amorphous thin films of lithium tantalate using a spray‐metalorganic chemical vapor deposition process. Annealing of the amorphous films results in their epitaxial alignment with respect to the underlying LiNbO3 or Al2O3 substrates. X‐ray diffraction, ion channeling, and scanning electron microscopy are used to evaluate and compare the crystalline quality of the films produced by this solid‐phase epitaxial process to films that are crystalline as deposited.

Improved solid phase epitaxial growth of lithium tantalate thin films on sapphire, using a two‐step metalorganic chemical‐vapor deposition process

Epitaxial lithium tantalate thin films were grown on sapphire substrates by metal‐organic chemical‐vapor deposition using a two‐step growth process. After an initial thin (≊30–100 A thick) amorphous buffer layer of LiTaO3 was deposited and annealed to induce crystallization by solid phase epitaxy (SPE), a second, thicker amorphous lithium tantalate layer was deposited and also crystallized using SPE. The use of the buffer layers substantially improved the crystalline quality of the heteroepitaxial films, with the thickest buffer layer providing the best results. The films were characterized by ion channeling, x‐ray diffraction and scanning electron microscopy.

Synthesis and raman spectra of unsymmetrical organotellurides containing a tellurium/group IV a element bond (ArTeMPh3; M = Ge, Sn, Pb)

A series of tellurium(II) compounds containing tellurium/Group IV A element bonds of the general formula ArTeMPh3 (Ar = phenyl, p-tolyl, p-anisyl, p-bromophenyl; M = Ge, Sn, Pb)were prepared and examined by various chemical and spectroscopic means, including Raman spectroscopy, for characterization of metal—metal bond vibrations. These materials are air-stable, light-yellow solids, soluble in a variety of organic solvents, and an excellent source of the ArTe radical in reactions with transition metals. In reactions of these compounds with complexes of copper and palladium, the tellurium/Group IV A element bond was cleaved, with formation of transition metal complexes formulated as TeAr-bridged polymers.

Single crystalline growth of LiNbO3 on LiTaO3 by spray metalorganic chemical vapor deposition using the single source precursor LiNb(OEt)6

Abstract Single crystal LiNbO 3 has been deposited on a z -cut LiTaO 3 substrate by a spray metalorganic chemical vapor deposition (MOCVD) process using the single source precursor LiNb(OEt) 6 . The surface morphology of the film has been characterized by scanning electron microscopy and its single crystal quality was established by X-ray diffraction (θ−2θ scans, rocking curve measurements and pole figure analysis) and Rutherford backscattering spectrometry combined with ion channeling.

Ultrahigh vacuum chemical vapor deposition of rhodium thin films on clean and TiO2-covered Si(111)

Abstract Thin film deposition by thermal decomposition of dicarbonyl (2,4-pentanedionato)rhodium(I), Rh(Co)2(C5H7O2), has been studied under ultrahigh vacuum conditions. Thin films were deposited on clean Si(111)−(7 × 7) and TiO2-covered Si(111) substrates, and in situ analyzed by Auger electron spectroscopy. Rhodium films deposited in the temperature range 200–500 °C contain carbon and oxygen impurities. The carbon and oxygen incorporation is more severe in the initial deposition stage on a clean silicon surface than on a growing surface. The initial impurity incorporation is greatly reduced with a deposited TiO2 overlayer.