Credit: (DOI: 10.1126/sciadv.aaq1442)
A team led by scientists at NREL demonstrated a way to use “negative pressure” to combine two dense materials into an alloy (right) with a much lower density, as if turning a snowball back into fluffy snow. The new alloy also has much different properties than either of its parents. The spheres represent atoms of manganese (blue), selenium (red) and tellurium (gold).