X-ray nanotomography characterizations of gold foams

Observation of the three-dimensional interior microstructure of low-density gold foams is very important for the optimization of their physical and chemical properties. We report on the three-dimensional internal microstructural imaging of gold foams by using X-ray computed tomography with a resolution of 50 nm. The gold foams are synthesized by the chemical dealloying method. By using focused ion beam milling technology, a foam micro-cylinder with a diameter of approximately 55 μm is prepared. The tomographical data sets of the micro-cylinder foam are collected in the angle range of ±90° at a photon energy of 8 keV. The data sets are then used to reconstruct the three-dimensional microstructure of the gold foams. The three-dimensional reconstruction information obtained from computed tomography provides an intuitive understanding of the gold foam structure.