Thermal Vibrations and Atomic Structure of Zinc Crystals at 100° and 298°K

The diffuse scattering of x-rays from single crystals of zinc has been investigated over a greater range of angles of scattering than in previous experiments. As a result of this more extended study, the root-mean-square displacements of the crystal atoms at $T=100\mathrm{}$°K are 0.098 and 0.050A for orientation angles of 0° and 90°, respectively. At the melting point of zinc it is likely that the root-mean-square displacement in a given direction is not more than 8 percent of the axial distance in the same direction. The atomic structure factors at a scattering angle of 90° are somewhat larger than would be expected on quantum-theoretical grounds. At large scattering angles the curves of the intensity of the scattered rays approach each other irrespective of temperature or orientation, the intensity approaching that of x-rays scattered from a gas of zinc atoms.