Longe Range Exchange Interactions in Sintered CuMn Alloys: A Monte Carlo Study

It is presented a Monte Carlo (MC) study of the dependency of the magnetization of sintered CuMn alloys with the temperature and applied magnetic field using a RKKY function to model the Mn-Mn magnetic interaction. Two kinds of simulations were done: (i) simulations at zero magnetic field, where the energy is obtained as a function of the temperature and (ii) simulations at constant temperature, varying the applied magnetic field. For both kinds of simulations, the variations of the total energy and the magnetization with respect to the concentration x and the range of the interaction (cutoff distance) were calculated. These simulations indicate that the range of the interaction among the magnetic atoms has a significant impact on the thermodynamic properties of the studied alloy.

The Surface Tension of Nanobubbles and the Effect of the Potential Cutoff Radius

Molecular dynamics (MD) simulations are carried out to calculate the surface tension of bubbles formed in a metastable Lennard-Jones (LJ) fluid. The calculated normal and transverse pressure components are used to compute a surface tension which is compared to the surface tension computed from the Young-Laplace equation. Curvature effects on surface tension are investigated by performing various sized simulations ranging from 6,912 to 256,000 LJ particles. Density profiles, pressures, and calculated surface tension are shown to have a strong dependence on the choice of the interaction cutoff radius. A cutoff radius of 8σ, significantly larger than that commonly used in the literature, is recommended for accurate calculations in liquid-vapor systems.