Particle-size dependence of phase stability and amorphouslike phase formation in nanometer-sized Au-Sn alloy particles - art. no. 094101

摘要

The effect of particle size on the phase stability in nanometer-sized Au-Sn alloy particles has been studied by transmission electron microscopy. When the composition of alloy particles falls in the two-phase region in the phase diagram for the bulk material, two phases expected from the phase diagram were produced in particles of larger than 10 mm in diameter, whereas no interfaces between two different phases can be recognized in the interior of individual alloy particles to produce an amorphouslike phase below 6-nm-sized alloy particles. The amorphouslike phase directly changes into a liquid phase with increasing temperature and then the reversible transformation occurs with decreasing temperature. The changes in the free energy in nm-sized particles bringing about melting temperature depression may play an important role in the stability of amorphouslike phases. [References: 19]