Rietveld analysis 18 goethite 10 Rietveld refinement 8 X-ray diffraction 8 Iron compounds 6 X ray diffraction 6 crystal structure 6 dissolution 6 Acid dissolution 4 Chemical analysis 4 Crystallinities 4 Crystallite size 4 Hyperfine characterization 4 Infrared spectroscopy 4 Mössbauer spectroscopy 4 Rietveld 4 Scanning electron microscopy 4 Ssbauer spectroscopies 4 aluminum 4 chromium 4 cobalt 4 manganese 4 Hexacyanoferrate (III) 3 Thermal decomposition 3 ANALISIS TERMICO 2 Acid concentrations 2 Activation energy 2 Adsorption 2 Aging time 2 Al- 2