Thermal properties of nonstoichiometry uranium dioxide

10th International School-Conference on Materials for Extreme Environment: Development, Production and Application

Kavazauri, R.^1 ; Pokrovskiy, S.A.^1 ; Baranov, V.G.^1 ; Tenishev, A.V.^1

National Research Nuclear University MEPhI, Moscow Engineering Physics Institute, 31 Kashirskoe highway, Moscow

115409, Russia^1

关键词: Non-stoichiometry;    Oxygen potential;    Solid electrolyte galvanic cell;    Thermal characteristics;    Thermogravimetric method;    Uranium oxides;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/130/1/012025/pdf
DOI  :  10.1088/1757-899X/130/1/012025

来源: IOP

【 摘 要 】

In this paper, was developed a method of oxidation pure uranium dioxide to a predetermined deviation from the stoichiometry. Oxidation was carried out using the thermogravimetric method on NETZSCH STA 409 CD with a solid electrolyte galvanic cell for controlling the oxygen potential of the environment. 4 samples uranium oxide were obtained with a different ratio of oxygen-to-metal: O / U = 2.002, O / U = 2.005, O / U = 2.015, O / U = 2.033. For the obtained samples were determined basic thermal characteristics of the heat capacity, thermal diffusivity, thermal conductivity. The error of heat capacity determination is equal to 5%. Thermal diffusivity and thermal conductivity of the samples decreased with increasing deviation from stoichiometry. For the sample with O / M = 2.033, difference of both values with those of stoichiometric uranium dioxide is close to 50%.