Engineering Commons^™

Near-Surface Material Phases And Microstructure Of Scandate Cathodes, Xiaotao Liu, Bernard K. Vancil, Matthew J. Beck, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Scandate cathodes that were fabricated using the liquid-solid process and that exhibited excellent emission performance were characterized using complementary state-of-the-art electron microscopy techniques. Sub-micron BaAl₂O₄ particles were observed on the surfaces and edges of tungsten particles, as seen in cross-section samples extracted from the scandate cathode surface regions. Although several BaAl₂O₄ particles were observed to surround smaller Sc₂O₃ nanoparticles, no chemical mixing of the two oxides was detected, and in fact the distinct oxide phases were separately verified by chemical analysis and also by 3D elemental tomography. Nanobeam electron diffraction confirmed …