Low energy electron microscopy study of directionally solidified LaB6-(Zr, V)B2 eutectics

LaB
₆
eutectic materials show promise as a replacement for common thermionic cathode materials. This eutectic system belongs to a class of materials referred to as directionally solidified eutectics (DSEs). LaB
₆
DSEs consist of a LaB
₆
matrix with a second phase, a metal di-boride, forming cylindrical rods in the matrix. Previous investigations on this material were focused on its use as a high temperature structural material. Use as a thermionic emitter remains largely unexplored.