Low-energy Electron Microscopy - Surface Diffraction

Surface Diffraction

Kinematic or elastic backscattering occurs when low energy (1-100 eV) electrons impinge on a clean, well-ordered crystalline specimen. It is assumed that each electron undergoes only one scattering event, and incident electron beam is described as a plane wave with the wavelength:


\begin{align}
\lambda = \frac{h}{\sqrt{2mE}}, \qquad \lambda=\sqrt{\frac{150}{E}}
\end{align}

Scientists use inverse space to describe the periodicity of the lattice and the interaction of the plane wave with the sample surface. In inverse (or "k-space") space, the wave vector of the incident and scattered waves are and, respectively,

and constructive interference occurs at the Laue condition:

where (h,k,l) is a set of integers and

is a vector of the reciprocal lattice.

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