Instrumental line-profiles measured as parts of X-ray diffraction patterns may be interpreted as convolutions of instrumental line-profiles and pure line-profiles, containing information on crystalline microstructure of investigated materials. Instrumental line profiles are important for precision of powder X-ray diffraction analyses. They can be measured from a standard material of same composition as a studied material that consists of sufficiently big and unstrained crystallites to ensure negligible contribution to line-profiles from crystalline microstructure in comparison to contribution from all instrumental factors. Frequently such standard can be hardly obtained and some standard reference material should be used instead. This substitution makes necessary further numerical procedure for determining instrumental line-profiles corresponding to Bragg angles for a material under study. In this work two standard materials, lanthanum hexaboride and zinc oxide, are compared and possible source of little discrepancy between X-ray diffraction patterns from them is revealed. Lanthanum hexaboride (NIST SRM 660a) was supported by NIST (with certificate No MD20899, mean crystallite size of 8.8 µm and cubic unit cell parameter of 0.41569162 nm ± 0,00000097 nm). Zinc oxide powder was produced by crystallisation from vapour. The measurements were performed by using a powder diffractometer (DRON) in the Bragg-Brentano configuration with radius of 180 mm, equipped with a cobalt X-ray tube (BWS-29), emission slits of 2 mm, receiving slit of 0.5 mm and Soller slit of 2°30'. X-ray diffraction pattern were recorded in range 20°-164° 2θ in scanning mode with step of Δ2θ=0.01° and counting time 3sec/step. The line profiles from lanthanum hexaboride were described by using fundamental parameter approach [1] and from them the line profiles corresponding to Bragg angles from zinc oxide were computed and compared with those from zinc oxide. The crystalline structure of SRM 660a was accounted [2]. The conclusions will be presented.

[1] R.W. Cheary, A. Coelho: A fundamental parameter approach to X-ray line-profile fitting, J. Appl. Cryst. 25 (1992), 109-121.
[2] C.T. Chantler, N.A. Rae, C.Q. Tran: Accurate determination and correction of the lattice parameter of LaB₆ (standard reference material 660) relative to that of Si (640b), J. Appl. Cryst. 40 (2007), 232-240.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/15463 must be provided.

1. Investigation of the products of the BaBiO_3-x reaction with TiO₂ using the high temperature RTG attachment
2. Microstructural evolution and formation of titania-doped mullites from heated single-phase gels
3. The Curie point of lead-barium zirconate titanate PZT ceramic
4. Synthesis of Nano-Powder Materials Using Spray-Pyrolysis Method.