Applications of Fourier Transform Infrared and X-ray techniques to analyze nickel ferrite nanoparticles produced PORTO, Paulo Sergio da Silva 2,a , PROVETI, José Rafael C. 1,b , Muniz, E. P. 1,c , Pereira, R. D. 1 , Araujo, D. R. 3 1 Univ. Federal do Espírito Santo, DCN, Rod. Br 101, km 60, São Mateus, ES, 29932-540, Brasil 2 Univ. Federal do Espírito Santo, DECOM, Rod. Br 101, km 60, São Mateus, ES, 29932-540, Brasil 3 Univ. Federal do Espírito Santo, Rod. Br 101, km 60, São Mateus, ES, 29932-540, Brasil a pauloporto@ceunes.ufes.br , b jose.rafael.proveti@pq.cnpq.br c eduardomuniz@ceunes.ufes.br Keywords: nanoparticles, sol-gel method, infrared. Abstract. Various methods have been reported to obtain nanosized ferrite particles such as chemical coprecipitation, sol-gel, spray-drying, microwave plasma, sonochemical, hydrothermal synthesis, reverse micelle technique and mechano synthesis. In this work Nickel Ferrite nanoparticles are produced using coconut water or pectin extracted from apple peel (using sulfuric or chloridric acid) as precursor for the proteic sol-gel (PSG) method. The samples are prepared by drying and subsequent isothermal treatment of the sol gel at 873 or 1173 K during 2 hours. The resultant materials were analyzed by Fourier Transform Infrared Spectroscopy (FTIRS) and discussed with emphasis in the purity of the samples produced. Introduction Nickel ferrite (NiFe2O4) is one of the most important spinel ferrites as well as a typical spin soft- magnetic ferrite. It has an inverse spinel structure showing ferrimagnetism that originates from the resultant magnetic moment due to the anti-parallel spins of Fe3+ ions at tetrahedral sites and Ni2+ ions at octahedral sites [1], Fig.1. The magnetic properties of NiFe2O4 exhibit a strong dependence on the crystallite size. NiFe2O4 samples exhibit ferrimagnetism, superparamagnetism, or paramagnetism depending on their microstructure [2, 3]. Ferrimagnetism is associated with polycrystalline samples with a grain size of 15 nm or more and superparamagnetism with samples of smaller grain size (10 nm). Paramagnetism is found in noncrystalline samples whose detailed structure may be either in the form of a crystalline anion lattice with disorder among the cation sites or more probably in the form of a totally disordered state Fig. 1 – Schematic representation of nickel ferrite structure. Due to the dependence of the properties of NiFe 2 O 4 on grain size and structure it is necessary to develop effective methods that allow the control of these variables [4]. Materials Science Forum Vols. 727-728 (2012) pp 884-887 Online available since 2012/Aug/24 at www.scientific.net © (2012) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/MSF.727-728.884 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 195.221.243.132-01/10/12,16:55:58)