ANALISIS STRUKTUR KRISTALIN HEMATITE YANG DISUBTITUSI ION MANGANES DAN ION TITANIUM

Abstract

Hematite (α-Fe2O3) is ceramic oxide which is largely used as the basic material of soft magnet and hard magnet. One effort to increase the characteristic of hematite magnet is continuously implemented through cation substitution; by using two and four valence ions like Mn2+, Co2+and Ti 4+ to replace the position of Fe3+. This research is aimed for observing the influence of substitution between Mn and Ti towards the formulation of Fe2-x-yMnxTiyO3 by using Rietveld analysis and GSAS (General Structure Analysis System) software. The Fe2-x-yMnxTiyO3 powder was synthesized by using milling method prior to solid solution process at the temperature of 1300°C. The x-ray diffraction (XRD) data was used for crystal analyzes by observing the diffraction intensity at the angle of 2θ = 20° until 80°. The composition of phase and lattice parameter was analyzed by using Rietveld method-based GSASEXPGUI program. The composition data validation of phase Fe2-x-yMnxTiyO3 used x-ray fluoresence (XRF) utilities in order to know the composition of each component. A refinement was implemented towards crystallized parameter such as crystal structure, lattice parameter and sample density to result in measurement validity. The grain size of crystal was calculated by using Scherer equation at five highest peaks for each composition. The refinement result showed the formulation of two phases; they were Fe2-x-yMnxTiyO3 as the primary phase and Fe2TiO5 as the secondary phase. Phase Fe2-x-yMnxTiyO3 was similar to phase α-Fe2O3 after the parameter was changed from a = 5,0355 Å until 5.0453 Å and the c value from 13.7410 Å until 13.7646 Å. The substitution process at the same temperature changed the size of crystalline size from 540 nm until 560 nm.