%0 Journal Article
%T Manganese-Nanoparticles Substitutions on the Vanadium Sites of Bi-Sr-Vanadate Aurivillius Ceramics
%A Khaled M. Elsabawy
%A M. M. Abou-Sekkina
%A A. El-Maghraby
%A M. A. Asker
%J International Journal of Inorganic Chemistry
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/751676
%X The aurivillius phase of Mn-substituted samples with general formula where and 0.6 mole were prepared by solid-state reaction technique and ceramics procedures. The X-ray structural measurement analysis confirmed the formation of single-phase-layered hexagonal structure which is observed in all samples. The thermal stability and phase change of the green powders were studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). SEM revealed that the average grain size increases with increasing Mn content. The infrared absorption spectra recorded a series of vibrational modes within the range of 400¨C1600£¿cm£¿1 were investigated. The present work also studied the effect of Mn-doping concentration interactions on both DC-electrical conductivity and ESR spectra. 1. Introduction Ferroelectic aurivillius ceramic has attracted the attention of many investigators due to its potential applications in electronics devices (DRAMs) [1¨C3]. Recently, there is interest in the study of bismuth-layered-structured ferroelectric materials for memory applications; one of the bismuth-layered-structured compounds is a promising candidate for ferroelectric random access memories (FRAM) as it has very little fatigue under polarization switching [4]. The study of microstructure of the SBN thin film is very important [5, 6]. The antiphase boundaries [APBs] are important factors of Bi-layered perovskite properties [7¨C9]. The layered crystal structure compounds have an anisotropic lamellar morphology, in which the major faces of the lamellar are perpendicular to the c-axis of the structure. In order to use moderate sintering temperatures so as to prevent compositional changes and exaggerated grain growth, and to attain low porosity, the ceramics of these compositions must be prepared by hot pressing technique [10¨C13]. Several bismuth-layered perovskites such as strontium bismuth niobate [SBN] [12] and strontium bismuth tantalate [SBT] [14] have been shown to exhibit much elongated fatigue durability and are capable of withstanding 1012 erase and rewrite operations. It is found that the substitution of niobium with vanadium in SrBi2Nb2O9 leads to enhancement of ferroelectric properties together with a lowered processing temperature [15, 16]. It has recently been reported that there occurs (BiFeO3) doped Sr Bi Nb [17]. Most of the work of the layered perovskite Sr Bi oxides reported on the improvement of the dielectric and ferroelectric properties is based on A-site substitution [18, 19]. For example, the replacement of Sr2+ ions by a smaller cations Ca2+
%U http://www.hindawi.com/journals/ijic/2012/751676/