Standard x-ray diffraction patterns

Abstract

Improve ment of t he X -ray diffraction pattern file of t he America n Society fo r T esti ng M aterials is t he bas is for work being don e at t he N ational Bureau of Standards wi t h t he cooperat ion of t he Joint Co mmi ttee on Che mical Analysis by X -ray Diffraction Methods of t he Ameri can Society for T est ing Materials , t he America n Cr ystallographic Associa t ion, an d t he Bri tish Inst it ute of Phy sics. The equipment used in obtainin g t he d ata presented her e comprises a Geiger-count er spectrometer wit h a 180 0 ar c calibrated with t he calculat ed patterns of substances whose lattice const ants are known with high pr ecision . Separate chart s are prep ared to ob tain dat a for interplanar spa cing and intensity m easurements so t hat special attention can be paid t o mounting t he sample for t he best result s in each case. Tables are in cluded t o com pare t he patterns with t hose recorded in the literature.