Premium
A liquid‐helium cryostat for collection of three‐dimensional X‐ray intensity data down to 20 K. The crystal structure of d (+)‐tartaric acid at 35, 105, 160 and 295 K
Author(s) -
Albertsson J.,
Oskarsson Å.,
Ståhl K.
Publication year - 1979
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889879013224
Subject(s) - cryostat , diffractometer , intensity (physics) , crystal (programming language) , x ray , crystallography , tartaric acid , scattering , helium , diffraction , liquid helium , thermal conduction , chemistry , materials science , crystal structure , optics , physics , condensed matter physics , programming language , superconductivity , organic chemistry , composite material , computer science , citric acid
A Be‐walled conduction cooling He( l ) cryostat intended for the interval 20–80 K and the κ geometry of the CAD4 X‐ray diffractometer is described. Three‐dimensional X‐ray intensity data can be collected in the interval − 45 < χ < 45° with the temperature stability maintained within ± 1 K. The experimental problems caused by centering an unseen crystal and by the absorption and scattering in the Be walls are discussed. d (+)‐tartaric acid, C 4 H 6 O 6 , was chosen as a test compound. Only minor differences occur in its crystal and molecular geometry between 295 and 35 K.