Microscopic origin of the effect of substrate metallicity on interfacial free energies

We investigate the effect of the metallic character of solid substrates on solid–liquid interfacial thermodynamics using molecular simulations. Building on the recent development of a semiclassical Thomas–Fermi model to tune the metallicity in classical molecular dynamics simulations, we introduce a thermodynamic integration framework to compute the evolution of the interfacial free energy as a function of the Thomas–Fermi screening length. We validate this approach against analytical results for empty capacitors and by comparing the predictions in the presence of an electrolyte with values determined from the contact angle of droplets on the surface. The general expression derived in this work highlights the role of the charge distribution within the metal. We further propose a simple model to interpret the evolution of the interfacial free energy with voltage and Thomas–Fermi length, which allows us to identify the charge correlations within the metal as the microscopic origin of the evolution of the interfacial free energy with the metallic character of the substrate. This methodology opens the door to the molecular-scale study of the effect of the metallic character of the substrate on confinement-induced transitions in ionic systems, as reported in recent atomic force microscopy and surface force apparatus experiments.

New Radical Cation Salts Based on BDH-TTP Donor: Two Stable Molecular Metals with a Magnetic [ReF6]2− Anion and a Semiconductor with a [ReO4]− Anion

Three radical cation salts of BDH-TTP with the paramagnetic [ReF6]2− and diamagnetic [ReO4]− anions have been synthesized: κ-(BDH-TTP)4ReF6 (1), κ-(BDH-TTP)4ReF6·4.8H2O (2) and pseudo-κ″-(BDH-TTP)3(ReO4)2 (3). The crystal and band structures, as well as the conducting properties of the salts, have been studied. The structures of the three salts are layered and characterized by alternating κ-(1, 2) and κ″-(3) type organic radical cation layers with inorganic anion sheets. Similar to other κ-salts, the conducting layers in the crystals of 1 and 2 are formed by BDH-TTP dimers. The partial population of positions of Re atoms and disorder in the anionic layers of 1–3 are their distinctive features. Compounds 1 and 2 show the metallic character of conductivity down to low temperatures, while 3 is a semiconductor. The ac susceptibility of crystals 1 was investigated in order to test the possible slow relaxation of magnetization associated with the [ReF6]2− anion.

Two-dimensional FeTe2 and predicted Janus FeXS (X: Te and Se) monolayers with intrinsic half-metallic character: Tunable electronic and magnetic properties via strain and electric field

Driven by the fabrication of bulk and monolayer FeTe2 ACS Nano 2020, 14, 9, 11473-11481], we explore the lattice, dynamical stability, electronic and magnetic properties of FeTeS and FeSeS Janus...

Study of Relative Metallic Character of Noble Metals Cu, Ag and Au at Normal Temperatures

The relative metallic character of noble metals, Cu, Ag & Au has been suggested by their physical and chemical properties. Their position in the metallic series is in the neighborhood of that of Li, Mg and Zn. These Metals are inferior of Li, Mg, Zn, Fe, Co and Ni in metallic character. Li, Mg, Zn, Fe, Co and Ni are inferior to Na, K, Rb, Cs, Ca, Ba and Sr. The noble metals have simple metallic character in physical properties at normal temperatures.

Electron Deficiency but Semiconductive Diamond-like B2CN Originated from Three-Center Bonds

B2CN was one of the synthesized light element compounds, which was expected to be superhard material with metallic character due to its electron deficiency nature. However, in this work we discovered...