METHOD OF DETERMINING CHEMICAL TRANSFER COEFFICIENT AND CHEMICAL DIFFUSION COEFFICIENT OF OXYGEN IN OXIDE MATERIALS

摘要

FIELD: chemistry.SUBSTANCE: method includes using the value of oxygen pressure over an oxide in a closed constant-volume gas loop as a parameter of the oxide which is directly linked to variation of the amount of oxygen in the oxide. The method includes placing an analysed sample in a reactor which is vacuum-tight connected to the gas loop which is insulated from the atmosphere; evacuating the gas loop to a high vacuum, and for abrupt change of oxygen pressure over the sample, closing the vacuum-tight connection of the reactor with the gas loop, releasing into or pumping out high-purity oxygen to a pressure value different from the equilibrium value, followed by opening the vacuum-tight connection of the reactor with the gas loop and recording change in the oxygen pressure over the sample over time, and calculating the chemical transfer coefficient and chemical diffusion coefficient of oxygen based on the relationship between relative change in oxygen pressure over the oxide and time, obtained after changing the oxygen pressure value.EFFECT: enabling instantaneous change of oxygen pressure, wider operating temperature range for samples with high chemical transfer and diffusion coefficients, low oxygen consumption compared to prototype systems, high accuracy of measuring pressure in a system for oxides with low chemical transfer and diffusion coefficients.2 dwg