An X-ray transmission diffractometer with a high temperature camera for the study of liquids

A horizontal diffractometer has been set up for transmission studies of liquid samples. An asymmetric, singly bent LiF monochromator in the primary X-ray beam focuses the radiation on the receiving slit of the diffractometer. The sample rotates at half the angular speed of that of the X-ray detector to retain focusing at all angles of diffraction. A high temperature furnace assembly (camera) has been constructed which fits on the diffractometer. Its heating element consists of a thin-walled, pyrolitic graphite tube 38 mm in diameter. A special sample holder for the liquids is mounted on a boron nitride stool bolted to the bottom plate of the camera. The entire set-up allows the measurement of the diffracted intensity between 2θ = 2° and 2θ = 90° corresponding to K = 4πsinθ/λ = 0.3 Å⁻¹ at 12.4 Å⁻¹ when Mo Kα radiation is used. Correction procedures to obtain the scattered intensity per atom from the raw data are discussed, and a comparison is made between the transmission and reflection methods with liquid tin.