International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Impact Factor (2012): 3.358 Volume 3 Issue 6, June 2014 www.ijsr.net Licensed Under Creative Commons Attribution CC BY Influence of Neutron Flux on Frequency Dependence of Dielectric Properties of Nano SiO 2 Elchin Huseynov, Adil Garibov, Ravan Mehdiyeva Institute of Radiation Problems of Azerbaijan National Academy of Sciences AZ 1143, B.Vahabzadeh 9, Baku, Azerbaijan Abstract: At the present work nano SiO 2 has been irradiated by 2x10 13 cm -2 s -1 neutron flux at different times up to 20 hours. It has been comparatively analyzed the frequency dependencies of dielectric constant of the nanomaterial exposed to neutron flux influence and initial state. From analysis results it has been revealed that the dielectric constant of nano SiO 2 increases in general tendency with influence of neutron flux. The complex dependence of the real and imaginary parts of dielectric constant of nano silica particles has been reviewed at 100 K and 400K. Similar Cole-Cole diagrams existing in the dependencies it has been revealed that the value of the relaxation period is compatible with polarization of the nano silica. Keywords: nanomaterial, nano SiO 2 , neutron effect, dielectric property, permittivity PACS: 61.80.Hg, 61.80.-x, 77.22.Ch 1. Introduction Nano-size SiO 2 and its different-type mixtures have been in the focus point of world researchers in recent years [1-11]. Also, silica and its oxide compounds are widely applied as a sorbent and radiation-resistant material in electronics and detection of ionizing rays [12-18]. An oxide layer usually with nano size is formed on silica materials in application fields. Surface oxide layer protects silica from external influences, as well as affects its physical and surface physicochemical properties. On the other side SiO 2 in nano sizes has a wide application field in medicine and technology for its simple composition, easy obtain and also as an oxide dielectric resistant to external influences and as a material with different purpose. For these properties, silicon oxide is of great importance in space techniques and nuclear technology as well. Recently it has been defined the dependence of physical and surface physicochemical properties of oxide dielectrics on particle size, particularly, strong influence of volume electron excitation in nano size, of defects and other factors on surface. Thus, nano-size samples of classic oxide dielectric SiO 2 are again in the focus of attention of researchers in modern times. For this purpose, ionizing ray effect on physical and surface physicochemical properties of nano SiO 2 is studied and suggestions are prepared on application of the samples in different fields [1-18]. The defects being generated during the irradiation of nano SiO 2 by neutron flux create important changes in dielectric properties. The submitted article is devoted to the study of neutron effect on real and imaginary parts of dielectric constant (permittivity) of nano SiO 2 . It has been determined the dependency of properties of real and imaginary parts of dielectric constant of neutron-irradiated nano SiO 2 on irradiation period and frequency at different temperature changing field. The defects generated in nano-compound exposed to continuous neutron irradiation at various periods cause changes in dielectric properties of the sample. Thus, with increase of effect period of neutron flux, the numerical values of real and imaginary parts of dielectric constant change and in its turn this change is more in real part of dielectric constant than in imaginary one. As a main reason for the change in the work it has been mentioned the generation of extra charges in the sample under neutron flux influence. The generated extra charges change the system polarization and thus real and imaginary parts of permittivity. In the work it has also been observed a decrease in real and imaginary parts of permittivity in the samples with increase of external field frequency. This has been explained as a destruction of charges with different barrier energy in the system with frequency effect and thus, as a decrease of polarization. 2. Experiment From previous studies it is known that the specific surface area of nano material used in the experiment is 160m 2 /g, dimensions are 20nm and purity is 99,5% and some parameters of the used sample has been studied [19-23, manufacturing company: SkySpring Nanomaterials, Inc. Houston, USA]. Nano SiO 2 has been irradiated at full power mode (250 kW) by neutron flux with 2x10 13 cm -2 s -1 flux density in central channel (channel A1) at TRIGA Mark II light water pool type research reactor in “Reactor Centre” of Jozef Stefan Institute (JSI) in the city of Ljubljana of Slovenia. It is important to note that the JSI TRIGA reactor has been thoroughly characterized [24-29] and the computational model used for computational characterization has been thoroughly verified and validated [30,31] against several experiments. While working at full power mode, the neutron flux has the following composition parts [24,26]: 5.107x10 12 cm -2 s -1 (1±0.0008, E n < 625eV) for thermal neutrons, for epithermal neutrons – as 6.502x10 12 cm -2 s -1 (1±0.0008, E n ~ 625eV ÷ 0.1MeV), for fast neutrons - 7.585x10 12 cm -2 s -1 (1±0.0007, E n > 0.1 MeV) and finally for all the neutrons in central channel flux density is as 1.920x10 13 cm -2 s -1 (1±0.0005). Dielectric parameters of neutron-irradiated nano SiO 2 have been measured in “Novocontrol Alpha High Resolution Dielectric Analyzer” device at 0,09Hz – 2,3MHz range of Paper ID: 01201474 1094