Hindawi Publishing Corporation Journal of Powder Technology Volume 2013, Article ID 268070, 7 pages http://dx.doi.org/10.1155/2013/268070 Research Article Sol-Gel Synthesis of Mullite Starting from Different Inorganic Precursors Lucia Téllez Jurado, 1 Rosa María Arévalo Hernández, 1 and Enrique Rocha-Rangel 2 1 ESIQIE-I P N, UPALM-Zacatenco, Lindavista, 07738 M´ exico, DF, Mexico 2 Universidad Aut´ onoma Metropolitana, Avendia San Pablo 180, Colonia Reynosa-Tamaulipas, 02200 M´ exico, DF, Mexico Correspondence should be addressed to Enrique Rocha-Rangel; erochar@upv.edu.mx Received 17 March 2013; Revised 19 June 2013; Accepted 19 June 2013 Academic Editor: Tierry Barriere Copyright © 2013 Lucia T´ ellez Jurado et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Using silicotetraetilortosilicate (TEOS) mixed with aluminum tri-sec-butoxide (TSBAI) or aluminum cloaures mullite ceramics were created by the sol-gel method. Te quantities used of each substance were those that led to obtain stoichiometric mullite (3Al 2 O 3 ⋅2SiO 2 ). Te experimental methodology used for obtaining mullite consisted in: sol-gel synthesis of precursor materials, isothermal treatment of those materials, and characterization of resulting materials. In order to determine the advance of reactions during mullite formation, isothermal treatments between 300 ∘ C and 1600 ∘ C were performed, keeping the samples at each temperature during 4 h. From XRD results, it may be said that precursor powders originally amorphous start to crystallize in Al 2 O 3 and SiO 2 at 1200 ∘ C, and the mullite formation starts at 1200 ∘ C, with being completed at 1600 ∘ C. Te use of TSBAI favors the formation of mullite crystals at lower temperature. From SEM observations a microstructure that presents primary mullite with randomly oriented grains of secondary mullite with acicular shapes and sizes that range between 1.25 and 1.50 m long may be determined. 1. Introduction Materials from the SiO 2 -Al 2 O 3 system play an important role in the development of traditional and advanced ceramics. Mullite, a material obtainable at atmospheric pressures, is part of this system. Mullite is a rare mineral not found in abundant quantities in nature; although most of traditional ceramics have it as part of their fnal composition for mineral aluminosilicates are regularly used for its manufacturing. Te importance of mullite lies in its good mechanical, thermal, chemical, and electrical properties which remain under elevated temperatures (about 1500 ∘ C) [1–3]. Conventionally, mullite is produced by high temperature calcination of mixtures of SiO 2 and Al 2 O 3 [4]. Te activation of energy for ion difusion that takes place through the network of energy requires high temperatures; therefore, high sintering temperatures are required (>1700 ∘ C) to obtain dense bodies of mullite [5]. Moreover, the sol-gel process enables the production of amorphous and polycrystalline materials with special characteristics starting from submicron powders of high purity [6–8]. Its usefulness lies in the fact that it requires low temperatures to obtain dense bodies compared to traditional manufacturing methods by fusion [6–8]. One of the many uses of mullite takes place in the electronics industry where it is used as substrate [1, 3]. A substrate is the support on which an electronic circuit, consisting of conductors, dielectrics, and integrated components, is mounted. Te choice of substrate depends on the thermal, mechanical, and electrical characteristics of the circuit. Based on the above, the aim of this research is the development and characterization of mullite ceramics by the sol-gel method, in search of its applications as a substrate in electronics. 2. Experimental Te following experimental methodology for obtaining mul- lite consisted in the following steps. (i) Sol-gel synthesis of the mullite precursor materials.