Appareillage pour études radiocristallographiques sous pression et à température variable

A diamond-anvil high-pressure cell especially designed for a standard precession camera and its operation are described. The applied force is generated by means of a pneumatic device. Single crystals grown by Van Valkenburg's technique are maintained under high pressure (1-30000 bars) at adjustable temperature (20-220°C). A steel goniometer head provides facility of centring and orienting the crystal. Some results are given, including crystal growth, optical observation of the phase transition in cyclohexane and crystal structure of chloroform at ~7000 bars. Conditions for gathering precise intensity data are discussed.