By Shana Hutchins and Jenny Wells
The authors observed in real-time the transformation of a HfO2 nanorod from its room temperature to tetragonal phase, at 1000° less than its bulk temperature. Nanorod surfaces and twin boundary defects (pictured here) serve to kinetically trap this phase.
It’s a material world, and an extremely versatile one at that, considering its most basic building blocks — atoms — can be connected together to form different structures that retain the same composition.
Diamond and graphite, for example, are but two of the many polymorphs of carbon, meaning that both have the same chemical composition and differ only in the manner in which their atoms are connected. But what a world of difference that connectivity makes: The former goes into a ring and costs thousands of dollars, while the latter has