Low-Temperature, Mercury-Mediated Synthesis of Aluminum Intermetallics
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- 作者：Mikhail Khoudiakov ; Arthur B. Ellis ; John H. Perepezko ; Sungtae Kim ; and Keith D. Kepler
- 刊名：Chemistry of Materials
- 出版年：2000
- 出版时间：July 2000
- 年：2000
- 卷：12
- 期：7
- 页码：2008 - 2013
- 全文大小：235K
- 年卷期：v.12,no.7(July 2000)
- ISSN：1520-5002
文摘
The preparative-scale synthesis of intermetallic phases in the Al-Au and Al-Pd systemscan be achieved at the relatively low temperature of boiling Hg (~350 
C at 1 atm). Inparticular, Al2Au, AlAu, AlAu2, Al3Pd2, and AlPd can be made in high yield either as singleproducts or as multiple products by dissolution of the elements in liquid Hg, followed bydistillation of the solvent. The reaction products were determined by X-ray diffraction andelectron microprobe analysis. A systematic study reveals that the products of these reactionsdepend strongly on initial mole ratios. A thermodynamic phase stability analysis wasconducted using estimated free energies for the intermetallic phases. From these calculationsand from the observed products and their sequence of formation, some of the reactions areshown to be kinetically controlled. Direct synthesis reactions tend to be favored forconcentration ratios that correspond to intermetallic phases that exhibit a coexistence tieline with the Hg solution.
C at 1 atm). Inparticular, Al2Au, AlAu, AlAu2, Al3Pd2, and AlPd can be made in high yield either as singleproducts or as multiple products by dissolution of the elements in liquid Hg, followed bydistillation of the solvent. The reaction products were determined by X-ray diffraction andelectron microprobe analysis. A systematic study reveals that the products of these reactionsdepend strongly on initial mole ratios. A thermodynamic phase stability analysis wasconducted using estimated free energies for the intermetallic phases. From these calculationsand from the observed products and their sequence of formation, some of the reactions areshown to be kinetically controlled. Direct synthesis reactions tend to be favored forconcentration ratios that correspond to intermetallic phases that exhibit a coexistence tieline with the Hg solution.