Spinodal Theory: A Common Rupturing Mechanism in Spinodal Dewetting and Surface Directed Phase Separation (Some Technological Aspects: Spatial Correlations and the Significance of Dipole-Quadrupole Interaction in Spinodal Dewetting)

Abstract

The emerging structures in spinodal dewetting of thin nano films and spinodal decomposition of binary mixtures are found to be similar with certain differences attributed to the nonlinearities inherent in the wetting forces. This paper deals with the technological aspects of the spinodal processes by giving a brief account of the theory and to correlate the two phenomena termed as spinodal dewetting of thin nanofilms and surface-directed phase separation. The MC simulation micrographs at early stage of spinodal dewetting of a (linear) polymer film confined between two hard walls (using FENE potential between the beads on same chain and Morse potential between inter and intra chain beads) show similarities with surface-directed phase separation (using metropolis algorithm) in creation of holes. The spinodal dewetting is also criticized on the basis of global minimization of free energy emerging from dipole-quadrupole interactions. A novel molecular scale-driving mechanism coming from asymmetric interface formation in spinodal processes is also proposed. It can be believed that the modeling done with the films under confinement of two walls works as a classical mathematical ansatz to the dipole-quadrupole interaction coming from quantum origins and giving rise to lateral interactions in the process reflecting a colossal behavior in thin nano films though weak in nature.

Deep learning on the 2-dimensional Ising model to extract the crossover region with a variational autoencoder

“…Furthermore, if H i > 0 , the spin at site i tends to prefer spin-up alignment, if H i < 0 , the spin at site i tends to prefer spin-down alignment, and if H i = 0 , there is no external magnetic field influence on the spin at site i. The model has seen extensive use in investigating magnetic phenomena in condensed matter phhysics [24][25][26][27][28][29] . Additionally, the model can be equivalently expressed in the form of the lattice gas model, described by the following Hamiltonian where the external field strength H is reinterpreted as the chemical potential µ , J retains its role as the interaction strength, and n i ∈ {0, 1} represents the lattice site occupancy.…”

The Ising Model: Brief Introduction and Its Application

“…Ising model has been extensively used for solving a variety of problems [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Some of the problems are discussed, here, with appropriate examples.…”

“…The interaction energy between A-A, B-B, and A-B type of atoms are represented by ε AA , ε BB , and ε AB , respectively. Phase separation has been studied vastly, using Ising model [4][5][6]. A phase is simply a part of a system, separated from the other part by the formation of an interface; that essentially means that two components aggregate and form rich regions of A and B type of molecules with an interface in between them.…”

Revisiting 2D Lattice Based Spin Flip-Flop Ising Model: Magnetic Properties of a Thin Film and Its Temperature Dependence

“…Though these 2D and 3D problems focus on mixing and dewetting in absence of magnetic field and only surface fields are present in form of chemical potentials in the models but these problems are different with this current problem under discussion in the sense that those discuss disordered binary mixture whereas the problem under discussion deals with complete ordering. The author would suggest going through the references Singh (2011) and Singh (2012) and would leave any further details. Ferromagnetism is shown by transition metals as iron, cobalt, nickel and some of the rare earth metals such as gadolinium (Gd).…”