Remarkably low value of work function on W(100) produced by Y-O composite layer

Electrical dipoles on a metal surface is believed to reduce the work function of the metal remarkably. Here, it is shown that slight yttrium layer with oxygen remarkably reduce the work function on W(100) surface. The reduced amount is much larger than Zr-O dipole on W(100). We believe YO/W(100) surface has a potential ability much better than the ZrO/W(100), which is widely adopted for scanning electron microscopes as bright cathodes.