Unexpected behavior of the crystal growth velocity at the hypercooling limit

Kurzfassung

We applied the electrostatic levitation technique in order to study the crystal growth velocity v as a function of the undercooling deltaT for the intermetallic, congruently melting binary alloy NiTi and the glass-forming alloy Cu–Zr, as well as for the Zr-based ternary alloys (NixCu1−x)Zr (x = 0.3, 0.4) and the Ni-based ternary alloy Ni(Zr0.5Ti0.5). For all investigated alloys hypercooling and beyond was achieved. Our results for glass-forming CuZr indicate that the influence of the diffusion coefficient D(T) on v(T) at high undercoolings, as claimed in literature, cannot be the sole reason for the existence of a maximum in the v(T) behavior.