Internal Pressures of Sodium, Potassium, and Rubidium Fluids at Different Temperatures

Abstract

In this paper, we calculate internal pressure of sodium, potassium, and rubidium and then use the internal pressure to predict X-ray diffraction and small-angle X-ray scattering to the range where the compressibility of the interacting electron gas has been theoretically predicted to become negative. Isotherms of internal pressure of rubidium fluid versus molar volume show a maximum around 1.152 g • cm -3 in agreement with X-ray diffraction and small-angle X-ray scattering. An attempt is made to establish a function for the accurate calculation of the internal pressure and the prediction of metal-nonmetal transition alkali metals based on the internal pressure.

Calculation of Thermal Pressure Coefficient of Lithium Fluid by pVT Data

“…In fact, the repulsive forces have an important role in the determination of the fluid structure, and the cohesive or attractive interactions in a fluid only define the fluid volume. The precise meaning of the metalnonmetal transition is contained in a generalized manner shows well depth in agreement with X-ray diffraction and small-angle X-ray scattering that the position of well depth maximum is a temperature-dependent quantity, and it also shows the metal-nonmetal transition residential [17][18][19][20][21].…”

“…These measurements involve its magnetic, electrical, structural, optical, and thermophysical properties with optimal control of temperature in the critical region. The fundamental difficulty in dealing with fluid metals is that the electronic structures of liquid and gas phases are completely different [17][18][19][20][21]. The electronic structure of lithium (and other molten metals) at low temperatures can be well approximated by the structure of the free electron gas, and thus the thermodynamic properties of metals can be obtained by the same cohesion mechanism of the free electron gas.…”

“…Problems have led us to try to establish a function for the accurate calculation of the internal pressure and the prediction of metal-nonmetal transition alkali metals based on the internal pressure [21].…”

“…In Section 2.4, temperature dependency of parameters has been developed to third order, and then thermal pressure coefficient is calculated by pVT data in each state for lithium fluid [16]. In Section 3, it has been shown that a gradual transition from metallic lithium to non-metallic lithium occurs when density decreases [17][18][19][20][21]. While the transition is occurring, a number of changes in the liquid structure happen, since the repulsion term of lithium potential energy versus temperature contains anomalous behavior, and it shows a well depth that the position of well depth maximum is the metal-nonmetal transition region of lithium.…”

Calculation of Thermal Pressure Coefficient of R11, R13, R14, R22, R23, R32, R41, and R113 Refrigerants by pVT Data

“…Problems have led us to try to establish a function for the accurate calculation of the internal pressure and the prediction of metal-nonmetal transition alkali metals based on the internal pressure [27].…”