Nucleation and Growth Behavior of Undercooled Pd_42.5Cu₃₀Ni_7.5P₂₀ Melt

Abstract

An undercooled Pd_42.5Cu₃₀Ni_7.5P₂₀ melt with a eutectic composition exhibits the lowest critical cooling rate for glass formation of 0.067 K/s. Nucleation and crystal growth behaviors of the undercooled melt were investigated at 683 K where the temperature is close to nose temperature. Nucleation frequency and crystal growth rate were evaluated as 4.77×10⁹⁄m³·s and 3.24×10⁻⁷ m/s, respectively. These values are almost the same as those for the undercooled Pd₄₀Cu₃₀Ni₁₀P₂₀ melt which has a slightly off-eutectic composition. However, the difference in incubation time for crystallization and nucleation mode was observed in both melts. Based on these results, the compositional effect on the stability of undercooled melt is discussed in the present study.