Fabrication of columnar orthorhombic AgTe via anomalous diffusion

We report the growth of columnar structures of orthorhombic AgTe by radio-frequency (RF) magnetron sputtering at room temperature. The structures were formed spontaneously by direct deposition of Te on Ag nanoparticles prepared by glancing angle deposition without exposure to air. Anomalous diffusion of Ag nanoparticles into the deposited Te led to the formation of columnar AgTe. The gaps in the columnar structure were filled with Te, which can be removed by sublimation. This is the first report on the preparation of orthorhombic AgTe by vapor deposition. The formation of columnar orthorhombic AgTe is attributed to the small grain size of the Ag nanoparticles, which prevents crystal nucleation of the stable Ag₂Te phase, and the non-oxidized Ag-Te direct interface, which induces fast anomalous diffusion and a strong electrochemical reaction.