PRECISE LATTICE PARAMETER DETERMINATION OF SPINEL MgAl2O4 FROM
X-RAY POWDER DIFFRACTION PATTERNS
Pages 32-35
P. Barvinschi, D.Tamas, R. Baies
Abstract
A very precise knowledge of the lattice parameters of materials is important in solid-state
investigations. In order to achieve high precision in lattice parameters measurements one can use the
popular methods based on plotting the lattice parameter as a function of some extrapolation functions
(Bradley-Jay, Nelson-Riley, etc) or applying the analytical Cohen method. Some new methods based on
the Rietveld-type pattern-fitting approaches can also be used. In this paper we present a comparative
study of these lattice parameter evaluation procedures. Diffraction data was recorded by Bragg-
Brentano X-ray diffractometry, using a set of MgAl2O4 powder samples presenting different
crystallinities. For the Rietveld-type analysis we used the FullProf programs package. Our results are
important for the studies involving systems of particles in the medium range diffraction angles (2Θ between 10° - 90°).