THERMOPHYSICAL CHARACTERISTICS OF LANTHANUM, PRASEODYMIUM AND EVOLUATION OF THERMAL PROPERTIES OF THEIR ALLOYS USING THE RULE OF MIXTURE OF COMPONENTS

10.25712/ASTU.1811-1416.2025.04.008

Abstract

Despite the widespread practical use of rare earth metals, there is almost no information in the scientific literature about the thermal physical properties of earth metals and their alloys. Existing thermodynamic models have both advantages and disadvantages, but none of them describe the behavior of the thermal properties of earth metals in the temperature range of the condensed state using a single continuous function. In this regard, a new approach to the theoretical representation of real systems was proposed. In the frame-work of the studied model, calculations were made for the thermal physical characteristics of lanthanum and praseodymium, such as heat capacity, thermal linear expansion coefficient, density, thermal conductivity, temperature conductivity, and specific electrical resistance. The obtained temperature dependencies adequately describe the experimental data. Using the rule of mixing components, estimates of the thermal properties of several lanthanum alloys with praseodymium have been obtained. The thermal properties of the alloys are limited by the corresponding characteristics of lanthanum and praseodymium. During the calculations, the effect of inheritance of a number of characteristics in the temperature curves of the components by the alloys was confirmed. However, it has been suggested that a more rigorous calculation could lead to the neutralization of this effect and the emergence of new collective phase transitions and structures as a result of the mixing of interacting components.