Rare Earth Hexaboride Nanowires: General Synthetic Design and Analysis Using Atom Probe Tomography

A general synthetic design for a wide range of single-crystalline rare earth hexaboride nanowires (REB 6, RE = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho) was established using palladium-nanoparticle-assisted chemical vapor deposition and examined by atom probe tomography analysis. Insights from binary phase diagrams were demonstrated to determine proper catalyst choice and vapor–liquid–solid growth conditions for this wide range of binary wire systems. High-resolution transmission electron microscopy indicated that these nanowires were single-crystalline with diameters of about 50 nm and lengths of several micrometers. Atom probe tomography analysis revealed that these nanowires were of high purity and correct stoichiometry. No detectable palladium diffusion was found beyond the first several nanometers of the catalyst nanoparticle–nanowire interface.