Errors from instrument Misalignment of the diffractometer △d 1 Dcos20 d Rsin0 Flat specimen instead of a curved one to correspond to the diffractometer circle,etc. △da2cos20 d 24sin20 Absorption of the specimen. △dcos20 d 2uR Vertical divergence of the incident beam. △d2cos2062 d24sin2024
Errors from instrument • Misalignment of the diffractometer • Flat specimen instead of a curved one to correspond to the diffractometer circle, etc. • Absorption of the specimen. • Vertical divergence of the incident beam. sin cos - 2 R D d d 2 2 2 24sin cos d d d R d 2 cos 2 24sin 24 cos 2 2 2 2 d d
Errors from instrument Displacement of specimen from the diffractometer axis(generally the largest source for error) △d Dcos20 Detector d Rsin0 X-ray beam Center of rotation D=specimen displacement D parallel to the reflecting Specimen plane normal Diffractometer circle R=diffractometer radius
Errors from instrument • Displacement of specimen from the diffractometer axis (generally the largest source for error)