- Organometallic access to intermetallic θ-CuE2 (E = Al, Ga) and Cu1-xAlx phases
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In this work, we compare different precursor approaches for the mild decomposition to copper-aluminum and -gallium powder materials in nonaqueous solution. Referring to previous work on the preparation of Cu-Al alloy materials from [(AlCp*)4] and [CpCu(PMe3)], the amine-stabilized metal trihydrides [(Me3N)AlH3] and [(quinuclidine)GaH3] were used as alternative sources for Al and Ga. In a comparative study, [(Me3N)AlH3] and [(AlCp*)4] were treated with the Cu precursors [CpCu(PMe 3)] and [{Cu(mesityl)}5] in mesitylene solution in various molar ratios at 150°C and 3 bar H2 to give metallic precipitates of the composition Cu1-xAlx (x = 0.67, 0.50, 0.31). Whereas the combination [(AlCp*)4] with [{Cu(mesityl)} 5] did not yield an intermetallic phase, all other Cu/Al precursor combinations led to alloyed Cu-Al materials. For x = 0.67, the θ-CuAl 2 phase formed, as shown by X-ray powder diffraction (XRD) and solid-state magic-angle-spinning (MAS)NMR spectroscopic studies. Similarly, the reaction of [{Cu(mesityl)}5] with [(quinuclidine)GaH3] immediately led to the precipitation of a gray powder, without the addition of hydrogen. The powder was identified by means of XRD as θ-CuGa2. At x = 0.50 and below, the reactions were less phase selective depending on the precursor combination. [CpCu(PMe3)] combined with both Al precursors afforded a mixture of several Cu-Al phases, whereas [{Cu(mesityl)}5] was treated with [(Me3N)AlH3] to yield a material whose X-ray signature was assigned to the monoclinic Cu0.51Al 0.49 phase. The γ-Cu9Al4 phase could not be obtained from [CpCu(PMe3)]; instead, solid solutions of α-Cu were obtained. The treatment of [{Cu(mesityl)}5] with [(Me 3N)AlH3] in the Cu/Al molar ratio of 9:4 (x = 0.31) gave a gray powder, which could be identified by XRD as γ-Cu9Al 4. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Cokoja, Mirza,Jagirdar, Balaji R.,Parala, Harish,Birkner, Alexander,Fischer, Roland A.
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- Aluminium Film Growth by Chemical Vapour Deposition of AlH3(NMe3)2
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The surface thermal decomposition mechanism of bistrimethylamine alane on the Ga rich (4*1) GaAs(100) surface was studied by thermal desorption spectroscopy (TDS), high resolution electron energy loss spectroscopy (HREELS), and XPS and was f
- Wee, Andrew T. S.,Murrell, Adrian J.,Singh, Nagindar K.,O'Hare, Dermot,Foord, John S.
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- Chemical vapor deposition precursor chemistry. 5. The photolytic laser deposition of aluminum thin films by chemical vapor deposition
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Thin films of very high purity aluminum were formed from the laser photolysis of trimethylamine alane (TMAA) using both ultraviolet (pulsed nitrogen) and visible (argon ion) laser irradiation on a variety of substrates including gold, Si(111), GaAs(110) and Teflon (PTFE). At thicknesses of up to 1 μm, nearly linear growth rates of 377 As-1 and 112As-1 were observed. The formation of volatile species formed during the deposition of aluminum from TMAA was investigated by quadrupole mass spectrometry (QMS) of the reactant gas stream. The highest intensity post-deposition mass fragments were observed at m/z 58, 43 and42amucorresponding to [NC3H8]+, [NC2H5]+ and [NC2H4]+, respectively. These species arise from the dissociation and subsequent fragmentation of the trimethylamine ligand from the starting TMAA complex. Semi-empirical quantum chemical calculations (MNDO) for TMAA provided further support that photolysis of this precursor should result in principally ligand dissociation processes since the LUMO orbital is primarily an aluminum-nitrogen antibonding interaction. The deposited materials were also characterized by X-ray emission spectroscopy (XES), scanning electron microscopy (SEM), and Laser Microprobe Mass Analysis (LAMMA) techniques.
- Glass Jr., John A.,Hwang, Seong-Don,Datta, Saswatti,Robertson, Brian,Spencer, James T.
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- Thermal Decomposition of Aluminium Hydride Complexes with Trimethylamine and N-Heterocyclic Carbene
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Abstract: The decomposition of aluminum hydride complexes with trimethylamine andN-heterocyclic carbene—1,3-bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene was studied by a statictensimetric method with a membrane null-manometer. TheAlH3·NMe3 complex passes intovapor in the form of monomeric molecules and in unsaturated vapor slowlydecomposes at 70?80°С into solid aluminum, gaseous trimethylamine, and hydrogen.The decomposition is accompanied by an induction period, the duration of whichdecreases as temperature increases. The AlH3 complex withcarbene slowly decomposes at 170?200°С with a rate practically independent oftemperature.
- Chernysheva, A. M.,Doinikov, D. A.,Kazakov, I. V.,Kravtcov, D. V.,Shcherbina, N. A.,Timoshkin, A. Yu.,Zavgorodnii, A. S.
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p. 1969 - 1976
(2021/11/13)
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- Aluminum nanoparticle preparation: Via catalytic decomposition of alane adducts-influence of reaction parameters on nanoparticle size, morphology and reactivity
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Al nanoparticles represent one of the most challenging classes of metal nanoparticles in synthesis and handling due to their high chemical reactivity and their affinity to oxidation. A promising wet chemical preparation route is the catalytic decomposition of alane adducts. In the current systematic study, we investigated the influence of various reaction parameters, such as precursors, catalysts, solvents, reaction temperatures, capping agents, and concentrations of the reactants on the size and morphology of the resulting Al nanoparticles. One major goal was the optimization of the reaction parameters towards short reaction times. Our studies revealed that Ti alkoxides, such as Ti(OiPr)4, are much more efficient decomposition catalysts compared to other related metal catalysts. Optimized conditions for full conversion times smaller than 15 min are temperatures between 90-100 °C and non-polar solvents such as toluene. Amine alanes containing short alkyl chains, for example H3AlNMe2Et or H3AlNEt3, were the most suitable precursors, leading to the formation of the smallest nanoparticles. The use of weakly coordinating capping agents like amines and phosphines should be preferred over the commonly employed carboxylic acids because they do not accelerate the formation of an amorphous oxide shell upon binding to the particle surface. In conclusion, the best reaction parameters for a fast synthesis of Al nanoparticles via a catalytic decomposition approach are the combination of sterically less hindered amine alanes applying a Ti catalyst in toluene solutions in the presence of amine or phosphine stabilizers at elevated temperatures.
- Kickelbick, Guido,Klein, Thomas
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supporting information
p. 9820 - 9834
(2020/07/30)
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- Proton-transfer and H2-elimination reactions of trimethylamine alane: Role of dihydrogen bonding and lewis acid-base interactions
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Proton-transfer and H2-elimination reactions of aluminum hydride AlH3(NMe3) (TMAA) with XH acids were studied by means of IR and NMR spectroscopy and DFT calculations. The dihydrogen-bonded (DHB) intermediates in the interaction of the TMAA wit
- Filippov, Oleg A.,Tsupreva, Victoria N.,Golubinskaya, Lyudmila M.,Krylova, Antonina I.,Bregadze, Vladimir I.,Lledos, Agusti,Epstein, Lina M.,Shubina, Elena S.
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p. 3667 - 3678
(2009/08/14)
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- SYNTHESIS OF ALUMINUM COMPOUND FOR FORMING ALUMINUM FILMS BY CHEMICAL VAPOR DEPOSITION
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The present invention relates to synthesis method of a precursor compound to deposit aluminum films on the substrate by chemical vapor deposition, and it provides the synthesis method of a compound defined as Formula 1 below. H2AlBH4 :N (CH3) 3
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(2010/11/29)
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