An asymmetric surface reflection of x rays was found. It was experimentally determined that this anomalously reflected wave has almost the same wavelength as the incident wave. The angle of this reflection changes only slightly with the incident angle and the crystal structure of the sample in the measured angular range. The glancing angle of this reflection increases with the wavelength of the incident x rays. According to measurements on evaporated surfaces of metallic elements, these reflection angles were found to have an important relation to the periodic system of the elements.

• Received 9 January 1963

DOI:https://doi.org/10.1103/PhysRev.131.2010