SE USA UNA VARIACIÓN DEL MÉTODO DE REFINAMIENTO RIETVELD PARA CALCULAR EL PORCENTAJE AMORFO DE COMPUESTOS FORMADOS POR ÓXIDOS DE FIERRO EMBEBIDOS EN UNA MATRIZ AMORFA DE SÍLICA XEROGEL. PARA REFINAR LA ESTRUCTURA AMORFA, SE PARTE DE UN MODELO CRISTALINO CON LA MISMA COMPOSICIÓN DEL MATERIAL QUE SE VA A MODELAR. EN ESTE TRABAJO SE PRETENDE REFINAR LA ESTRUCTURA DE LOS COMPUESTOS USANDO EL PROGRAMA MAUD. SE MUESTRA QUE EL PROGRAMA PUEDE SER USADO PARA DETERMINAR LAS FRACCIONES AMORFAS Y CRISTALINAS EN COMPUESTOS QUE CONSISTEN DE UNA MATRIZ AMORFA CON INCORPORACIÓN DE PARTÍCULAS DE ÓXIDO DE FIERRO. EL ANÁLISIS DE FASES SE REALIZA EN MUESTRAS CON DIFERENTES TRATAMIENTOS TÉRMICOS.AbstractWE USE A VARIATION OF THE RIETVELD REFINEMENT METHOD TO CALCULATE THE AMORPHOUS CONTENT OF COMPOSITES FORMED BY A SILICA XEROGEL AMORPHOUS MATRIX AND IRON PARTICLES EMBEDDED INTO. IN ORDER TO APPLY THE RIETVELD REFINEMENT TO AMORPHOUS STRUCTURES AN INITIAL CRYSTALLINE MODEL IS ASSUMED WITH THE SAME COMPOSITION AS THE MATERIAL TO BE MODELLED. IN THIS WORK WE TRY TO REFINE THE STRUCTURE OF COMPOUNDS USING THE PROGRAM MAUD. IT IS SHOWN HOW THIS PROGRAM CAN BE USED TO DETERMINE THE AMORPHOUS AND CRYSTALLINE FRACTIONS IN COMPOSITES CONSISTING OF AN AMORPHOUS MATRIX AND INCORPORATED IRON OXIDE PARTICLES. THE ANALYSED COMPOUNDS UNDERWENT DIFFERENT THERMAL TREATMENTS.WE USE A VARIATION OF THE RIETVELD REFINEMENT METHOD TO CALCULATE THE AMORPHOUS CONTENT OF COMPOSITES FORMED BY A SILICA XEROGEL AMORPHOUS MATRIX AND IRON PARTICLES EMBEDDED INTO. IN ORDER TO APPLY THE RIETVELD REFINEMENT TO AMORPHOUS STRUCTURES AN INITIAL CRYSTALLINE MODEL IS ASSUMED WITH THE SAME COMPOSITION AS THE MATERIAL TO BE MODELLED. IN THIS WORK WE TRY TO REFINE THE STRUCTURE OF COMPOUNDS USING THE PROGRAM MAUD. IT IS SHOWN HOW THIS PROGRAM CAN BE USED TO DETERMINE THE AMORPHOUS AND CRYSTALLINE FRACTIONS IN COMPOSITES CONSISTING OF AN AMORPHOUS MATRIX AND INCORPORATED IRON OXIDE PARTICLES. THE ANALYSED COMPOUNDS UNDERWENT DIFFERENT THERMAL TREATMENTS.