ISSN (Print): 2328-3777, ISSN (Online): 2328-3785, ISSN (CD-ROM): 2328-3793 American International Journal of Research in Formal, Applied & Natural Sciences AIJRFANS 19-301; © 2019, AIJRFANS All Rights Reserved Page 1 AIJRFANS is a refereed, indexed, peer-reviewed, multidisciplinary and open access journal published by International Association of Scientific Innovation and Research (IASIR), USA (An Association Unifying the Sciences, Engineering, and Applied Research) Available online at http://www.iasir.net Thermal Expansion Properties of Mixed Oxide ZrxTi1-xO2 Nanoparticles Deepak Kumar Sharma, Jagdhar Mandal University Department of Physics T.M. Bhagalpur University Bhagalpur-812007, Bihar INDIA I. Introduction The nanocomposites of mixed metal oxides can be tailored to have unique material characteristics by changing some physical, chemical, electronic and magnetic properties [1]. The combination of titania-zirconia mixed oxides have found widespread use as catalyst and catalyst support [2],[3] such as in photocatalysis, water photosplitting, gas sensors and in solid oxide fuel cells, composite materials, etc.[4], [7-12]. TiO2 in the macrocrystalline forms and nanocrystalline forms has major industrial applications such as in plastics, pigments, cosmetics and as a well known catalyst [5]. It exists in a number of polymorphs,of which rutile (tetragonal) is the stable phase and anatase and brookite are metastable[6]. ZrO2 also exists in a number of polymorphs of which tetragonal and the cubic polymorphs are used in catalytic applications due to their high thermal stability and amphoteric nature [2].The properties of the mixed oxides can be easily manipulated by controlling their composition. However their synthesis results in a mixture of different crystalline phases or pure material with varying particle sizes and changes in specific areas. Earlier the solubility limit of TiO2 in Zirconia, limited the doping concentration in ZrxTi1- xO2 nanoparticles but now it has significantly increased under high temperature and high pressure experiments [11], [12]. ZrxTi1-xO2 (0.0≤x≤1.0) mixed oxide nanoparticles show structural transformations under high temperatures with changes in crystalline cell parameters and phase transformations with varying concentrations of the doping material [12], [13]. Hayashi et al. have also reported considerable changes in the thermal properties for various mixed oxides [14], [15]. The behavior of the thermoelastic constants under the effect of temperature have been studied extensively both theoretically and experimentally for the bulk materials as well as the nanomaterials. There have been several equations of states to study the thermoelastic properties for different classes of solids [16]-[21]. However, in the proposed equation of state by assuming the linear dependence of Anderson Gruneisen parameter (δ T) with temperature we get better results on thermoelastic properties. Hence by using the Singh and Gupta [22] equation of state we have calculated the thermoelastic properties such as the thermal expansivity and relative bulk modulus for titanium dioxide-zirconium dioxide mixed oxides nanoparticles with varying concentrations of x : ZrxTi1- xO2 (0.0≤ x≤ 1.0). II. Method of Analysis One of the widely used thermodynamic approximation is that the product of thermal expansion coefficient (α) and the isothermal bulk modulus (KT) remains constant under the effect of temperature, i.e. αKT = constant (1) Differentiation of equation (1) with respect to T, at constant pressure gives Abstract: We present a theoretical model using the proposed equation of state to study the thermoelastic properties of the mixed oxide ZrxTi1-xO2 (0.0≤x≤1.0) nanoparticles under high temperatures. The thermoelastic properties viz. the thermal expansivity, relative bulk modulus of the mixed oxide nanoparticles ZrxTi1-xO2 and their variation with temperature have been discussed and compared with their experimental results. The variation in the concentration of the doping material ‘x’ in the host matrix TiO2 and the corresponding changes in the thermoelastic behavior of mixed oxide ZrxTi1-xO2 (0.0≤x≤1.0) nanoparticles have also been discussed in light of the observed phase transitions. Keywords: Mixed oxide ZrxTi1-xO2 nanoparticles; Thermal expansion; Bulk modulus; Phase transition