Research Article 1(1) 114-117 Advanced Materials Proceedings Copyright © 2016 VBRI Press 114 High Dielectric Constant SiO 2 Nanoparticles Sathosh K. Kurni, Pradip Paik * School of Engineering Sciences and Technology, University of Hyderabad, 500046, India * Corresponding author, E-mail: pradip.paik@gmail.com; Tel: (+91) 040-2313 4457 Received: 31 March 2016, Revised: 01 August 2016 and Accepted: 03 August 2016 DOI: 10.5185/amp.2016/120 www.vbripress.com/amp Abstract SiO 2 nanoparticles of average size 15-20 nm have been synthesized and its dielectric properties have been investigated as a function of frequency (between 20 Hz to 2 MHz). A very high dielectric constant of ca. 14000 at 20 Hz and at room temperature has been observed which is very high compared to the conventional bulk SiO 2 particles (ca. 50-100). For this new SiO 2 the loss value is found to be less than 1. These SiO 2 nanoparticles with high dielectric constant and low loss can be offered its use in constructing high efficient electronic circuit boards and storage devices. Spectra between real and imaginary parts of dielectric constant reveal an inclined line with depressed semicircle. Impedance measurements have been performed to know the electrical properties of the novel SiO 2 nanoparticles. XRD, TEM and FTIR characterizations confirm the solid state network structural, morphological shape and size, and chemical functionality of SiO 2 respectively. Copyright © 2016 VBRI Press Keywords: SiO 2 NPs, dielectric constant, dielectric loss, impedance, AC conductivity. Introduction Materials with high dielectric constant and low loss have potential applications in electronic industry and required new materials on current demands. SiO 2 nanoparticles (NPs) in various forms have wide variety of applications in different fields like electronics, bio imaging, drug delivery [1] and cancer therapy [2] etc. SiO 2 NPs are used as coatings in photovoltaic devices to reduce the reflectance [3]. Due to the development of Very Large Scale Integration technology (VLSI), use of low dielectric constant materials (low k) and high dielectric constant materials became mandatory. SiO 2 films can be used as low k material as well as high k material in the form of interlayer dielectric in transistors depending on its dielectric constant. Its dielectric constant can be increased/decreased by doping with carbon or fluorine and imparting porosity to it [4-6]. The common high k materials being used in electronic industry are SiO 2 , Hafnium silicate (HfSiO 4 ), and Zirconium silicate (ZrSiO 4 ) [7]. Interlayer dielectric should be in the form of films by requirement. Polymer dispersed with high k materials also can be used for the same followed by composite film formation [8]. The SiO 2 being used as gate oxide material in transistors encounters problems like leakage current and diffusion of metal layers and less gate capacitance for its lesser thickness (less than 2nm) [9]. Therefore a high k material is required which avoids such problems in the device. There has been a search for new high k materials with fewer inconveniences for the past decade. In this work a new ultra-fine SiO 2 NPs has been synthesized and its dielectric properties have been investigated as a function of frequency and temperature. The present material discussed in this article has very high dielectric constant when compared to conventional SiO 2 films (3.9) deposited through PECVD [10] and which can be used for increase in the efficiencies of the future generation electronic devices. Experimental Materials details TEOS (99.9%, Sigma Aldrich), Ethanol (99.3%, Merck) and NH 4 OH (99.9%, Sigma Aldrich) were used in their pure form for synthesis. Material synthesis Synthesis of SiO 2 NPs: The synthesis of SiO 2 NPs was done using sol-gel technique with a little modification. The detailed procedure of the method is as follows. Ethanol 30 ml was taken in a flask and 2 ml TEOS was added after 10 minutes under vigorous stirring. After 10 minutes 1 ml water was added to the reaction mixture. Stirring continued for 20 minutes then 3 ml NH 4 OH was added to it. Gel was formed after few minutes and was dried in a furnace at 80°C for overnight. A white powder of SiO 2 NPs was obtained. Characterizations High resolution transmission electron microscopy (HRTEM) (Model: FEI TECHNAI G2 200 kV S- twin) was used to find out the shape, size and