Structural Phase Control in Self-Catalyzed Growth of GaAs Nanowires

Jan 11, 2011 - which we have defined as the amount of excess free energy per. GaAs pair ... of Aix-Marseille University for making us aware of the pro...
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ADDITION/CORRECTION pubs.acs.org/NanoLett

Structural Phase Control in Self-Catalyzed Growth of GaAs Nanowires on Silicon (111) [Nano Letters 2010, 10, 4475– 4482. DOI: 10.1021/nl1041066]. Peter Kogstrup,* Ronit Popovitz-Biro,  and Erik Johnson, Morten Hannibal Madsen, Jesper Nygard, Hadas Shtrikman* Page 4477. In Figure 3b the liquid supersaturation is plotted, which we have defined as the amount of excess free energy per GaAs pair compared to liquid-solid equilibrium conditions. For phases consisting of more than one component, the liquid supersaturation is not the same as the Gibbs free energy change upon solidification (the driving force for the transformation). Even though the two quantities are strongly related, the driving force per GaAs pair is a more appropriate quantity with respect to the growth structure analysis and is given by Δμsl = 2(μs,As - μl,As) = 2(μs,Ga - μl,Ga) where μs,i and μl,i are the chemical potentials of component i of the solid phase and liquid phase, respectively, and is plotted in the figure below.

Figure 3. The driving force for axial growth of Au free GaAs nanowires with zinc blende structure, as a function of x in the liquid Ga1-xAsx phase. To calculate Δμsl first the tangent to the liquid free energy gl at the composition of the supersaturated liquid is traced. Then a line parallel to this tangent and tangent to the solid free energy is drawn. The difference between the two lines defines Δμsl.

To distinguish between chemical potentials and specific free energies, we would use g instead for μ as a symbol for the latter. Moreover on page 4477, μs should read gl,eq. We are grateful to Stefano Curiotto from the CINaM-CNRS of Aix-Marseille University for making us aware of the problem and for fruitful discussions on the thermodynamics. DOI: 10.1021/nl1041066 Published on Web 01/11/2011

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dx.doi.org/10.1021/nl1041066 | Nano Lett. 2011, 11, 918–918