A proper understanding of the Davisson and Germer experiments for undergraduate modern physics course

TL;DR

This paper explains the Davisson-Germer experiments using 2D Bragg scattering and surface diffraction, providing a clearer physical interpretation suitable for undergraduate physics education.

Contribution

It offers a detailed, surface-based interpretation of the experiments, emphasizing 2D Bragg reflection and diffraction grating concepts for educational purposes.

Findings

Ni surface acts as a reflective diffraction grating

2D Bragg reflection occurs at Ewald sphere intersections

Surface diffraction explains experimental results

Abstract

The physical interpretation for the Davisson-Germer experiments on nickel (Ni) single crystals [(111), (100), and (110) surfaces] is presented in terms of two-dimensional (2D) Bragg scattering. The Ni surface acts as a reflective diffraction grating when the incident electron beams hits the surface. The 2D Bragg reflection occurs when the Ewald sphere intersects the Bragg rods arising from the two-dimension character of the system. Such a concept is essential to proper understanding of the Davisson-Germer experiment for undergraduate modern physics course.