The Use of Rietveld Technique to Study Phase Composition and Developments of Calcium Aluminate


The phase composition and development of calcium aluminates (CA, CA2, and CA6) processed by in-situ
reaction sintering of AI203 and CaC03 have been studied by Rietveld refinement technique. The formation of calcium
aluminates is temperature-dependent. X-ray diffraction result revealed that the CA, CA2, and CA6 phases starts to
develop at approximately 1000DC,1100 °c and 1375DC,respectively. The relative phase compositions obtained from xray
diffraction patterns for the a-A1203 phase decreased markedly with increasing temperature, Le. from 86.0(1.1) wt %
at 1000 °c to 34.7(0.4) wt % at 1400DC.The wt % of CA decreased from 10.9(0.3) - 1.9(0.2) wt % at 1100 - 1200 °c
but disappeared at 1300 DC.The wt % of CA2 reached 36.0(0.7) wt % at 1300 °c and decreased to 18.5 (0.5) wt % at
1400°C. The wt % CA6 increased markedly from 1375 to 1400DC,i.e. 12.80(0.6)- 47.3(0.9) wt %. The goodness of fit
values is relatively low and the fluctuation in the difference plots shows a reasonable fit between the observed and the
calculated plot.
Keywords: X-ray diffraction, Rietveld technique, calcium aluminates (CA, CA2, and CA6).I. Ridwan and D. Asmi
iDepartment of Physics, Faculty of Mathematics and Natural Sciences, University of Lampung,
Il.Sumantri Brojonegoro No.1, Bandar Lampung 35145, Indonesia