On the dendrites and dendritic transitions in undercooled germanium

Undercooled molten Ge was allowed to solidify at initial bulk undercoolings, ΔT, from 10 to 200°C under dehydrated boron oxide flux. It turned out that in addition to the 〈211〉 twin dendrite found by Billig and the 〈100〉 twin-free dendrite discovered by Devaud and Turnbull, there is a third novel twin dendrite, the 〈110〉 twin dendrite. The twin planes in a 〈110〉 dendrite always appear in multiple numbers and the orientation is {111}. These different kinds of dendrites exist at different initial interfacial undercoolings and the transition temperatures for 〈110〉 to 〈211〉, 〈211〉 to 〈100〉 are †T = 61 and 93°C, respectively.