Plots the out-of-plane crystal momentum kz as a function of photon energy Ehv
This calculator plots the exact photon energy at which the photo-electron have out-of-plane crystal momentum either at Brillouin zone center (Gamma) or at zone boundary (Z). The photon momentum has been taken into account and therefore also valid for soft X-ray ARPES.
The equation used here is not limited to normal emission (electron emitting normal to sample surface) and made no approximation. It is numerically equivalent to the commonly used form, 0.5123√[V0 + (Ehv−W)] + Ehv/1973 · cos(45°), to within 1%. The ARPES experimental geometry is assumed to be vertical cryostat and horizontal slit. Note that for body centered lattices, c is the primitive cell lattice constant, that is half the conventional cell lattice constant.
Webpage maintained by Sean Kung at the University of British Columbia.