Quasi-elastic neutron scattering rates

The energy barriers of surface diffusion can further be inferred from quasi-elastic hehum atom scattering (HAS) [39, 40]. The kinetic energy of the He atoms that are scattered from diffusing atoms reveals a small additional broadening due to momentum transfer. In analogy to quasi-elastic neutron scattering, which has been used to study diffusion in solid and liquid bulk samples, this can be used to measure diffusion rates. Other than STM, this technique can be applied up to T [41]. 

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