Estimating mean crystallite size of magnetite using multivariate calibration and powder x-ray diffraction analysis

Resumo

Powder X-ray diffraction patterns for 29 samples of magnetite, acquired using a conventional diffractometer, were used to build PLS calibration-based methods and variable selection to estimate mean crystallite size of magnetite directly from powder X-ray diffraction patterns. The best IPLS model corresponds to the Bragg reflections at 35.4° (h k l = 3 1 1), 43.0° (h k l = 4 0 0), 53.6° (h k l = 4 2 2), and 57.0° (h k l = 5 1 1) in 2θ. The best model was a GA-PLS which produced a model with RMSEP of 0.9 nm, and a correlation coefficient of 0.9976 between mean crystallite sizes calculated using Williamson-Hall approach and the ones predicted by GA-PLS method. These results indicate that magnetite mean crystallite sizes can be predicted directly from Powder X-Ray Diffraction and multivariate calibration using PLS variable selection approach.
Pra{kovni posnetki 29 vzorcev magnetita, pridobljeni na konvencionalnem difraktometru, so bili uporabljeni za razvoj PLS kalibracijske metode in izbiro spremenljivk za oceno povpre~ne velikosti kristalitov magnetita direktno iz pra{kovnih posnetkov. Najbolj{i IPLS model ustreza Braggovim uklonskim kotom 35.4° (h k l = 3 1 1), 43.0° (h k l = 4 0 0), 53.6° (h k l = 4 2 2) in 57.0° (h k l = 5 1 1). Najbolj{i model je GA-PLS, s katerim smo dobili model z RMSEP 0,9 nm in korelacijskim koeficientom 0.9976 med povpre~no velikostjo kristalitov izra~unano z Williamson-Hallovim pristopom in tisto napovedano z GA-PLS metodo. Dobljeni rezultati ka`ejo, da lahko napovemo povpre~no velikost kristalitov magnetita neposredno iz pra{kovnega posnetka in multivariantne kalibracije z uporabo prostopa PLS izbire spremenljivk.

Descrição

Palavras-chave

Crystallite size, GA-PLS, Powder X-ray, Magnetite

Citação

LEMES, Maykon A. et al. Estimating mean crystallite size of magnetite using multivariate calibration and powder x-ray diffraction analysis. Acta Chimica Slovenica, Ljubljana, v. 61, n. 4, p. 778-785, Dec. 2014.