Analisis material ferroelektrik dengan X - Ray Diffraction (XRD) dan program rietveld (Studi kasus Kh2PO4)

Abstract

A mainframe based Rietveld program has been modifled for use on IBM Compatible personal Computers (PC). This PC version of Rietveld program is designed to handle most of the quantitative phase analysis problems with moderate structure complexity. To begin with, we have an IBM compatible 486 DXI33 MHz personal computer (RAM minimum 8 Mbyte), a Microsoft FORTRAN compiler (version 5.0) and the source code for mainframe based LHPM program D.Y.Li ; J.Y. Li and B H. O'Connor (1991) named the PC version of LHPM program as PCRTVD. KHzPO4 (KDP) crystallizes in a tetragonal structure above 123 K with a noncentrosymmetric point group42 m. Below T, an ortharombic phase exists (point group mm) which is ferroelectric whit the spontaneous polarization mainly due to the displacement of K, P and 0 ions in the direction of the polar c axis. Space group KDP is I - 42 d and Lattice parameter is a = 7,4532 A and c = 6,4742 A. Result form research Bragg R - Factor KDP with Rietveld program : 7,12 % (< 10Yo).