Janus Monolayer of 1T-TaSSe: A Computational Study.

Materials exhibiting charge density waves are attracting increasing attention owing to their complex physics and potential for applications. In this paper, we present a computational, first principles-based study of the Janus monolayer of 1T-TaSSe transition metal dichalcogenide. We extensively compare the results with those obtained for parent compounds, TaS and TaSe monolayers, with confirmed presence of 13×13 charge density waves.

Phase Diagram and Quantum Entanglement Properties of a Pentamer = 1/2 Heisenberg Spin Cluster.

Cluster molecular magnets prove their potential for applications in quantum technologies, encouraging studies of quantum entanglement in spin systems. In the paper we discuss quantum entanglement properties of pentamer cluster composed of spins S=1/2 forming a tetrahedron with additional spin in its center, with geometry reproducing the smallest nonplanar graph. We model the system with isotropic Heisenberg Hamiltonian including external magnetic field and use exact diagonalization approach to explore the ground-state phase diagram and thermodynamic properties within canonical ensemble formalism.

Two-Dimensional Crystals as a Buffer Layer for High Work Function Applications: The Case of Monolayer MoO.

We propose that the crystallinity of two-dimensional (2D) materials is a crucial factor for achieving highly effective work function (WF) modification. A crystalline 2D MoO monolayer enhances substrate WF up to 6.4 eV for thicknesses as low as 0.

Spin State Switching in Heptauthrene Nanostructure by Electric Field: Computational Study.

Recent experimental studies proved the presence of the triplet spin state in atomically precise heptauthrene nanostructure of nanographene type (composed of two interconnected triangles with zigzag edge). In the paper, we report the computational study predicting the possibility of controlling this spin state with an external in-plane electric field by causing the spin switching. We construct and discuss the ground state magnetic phase diagram involving S=1 (triplet) state, S=0 antiferromagnetic state and non-magnetic state and predict the switching possibility with the critical electric field of the order of 0.

Low-Temperature Magnetocaloric Properties of V12 Polyoxovanadate Molecular Magnet: A Theoretical Study.

The paper presents a computational study of the magnetocaloric properties of the V12 polyoxovanadate molecular magnet. The description is restricted to low-temperature range (below approximately 100 K), where the magnetic properties of the system in question can be sufficiently modelled by considering a tetramer that consists of four vanadium ions with spins S=1/2. The discussion is focused on the magnetocaloric effect in the cryogenic range.

Magnetocaloric Effect in Cu5-NIPA Molecular Magnet: A Theoretical Study.

We calculated the magnetocaloric properties of the molecular nanomagnet Cu5-NIPA, consisting of five spins S = 1 / 2 arranged in two corner-sharing triangles (hourglass-like structure without magnetic frustration). The thermodynamics of the system in question was described using the quantum Heisenberg model solved within the field ensemble (canonical ensemble) using exact numerical diagonalization. The dependence of the magnetic entropy and magnetic specific heat on the temperature and the external magnetic field was investigated.

Electrocaloric effect in cubic Hubbard nanoclusters.

In the paper a computational study of the electrocaloric effect is presented for a cubic nanocluster consisting of 8 sites. The system of interest is described by means of an extended Hubbard model in external electric field at half filling of the energy levels. The thermodynamic description is obtained within canonical ensemble formalism on the basis of exact numerical diagonalization of the system Hamiltonian.

Normal and inverse magnetocaloric effect in magnetic multilayers with antiferromagnetic interlayer coupling.

The thermodynamics of a spin-1/2 magnetic multilayer system with antiferromagnetic interplanar couplings is studied using the pair approximation method. Special attention is paid to magnetocaloric properties, quantified by isothermal entropy change. The multilayer consists of two kinds of magnetic planes, one of which is diluted.

Indirect RKKY interaction between localized magnetic moments in armchair graphene nanoribbons.

A form of indirect Ruderman-Kittel-Kasuya-Yosida (RKKY)-like coupling between magnetic on-site impurities in armchair graphene nanoribbons is studied theoretically. The calculations are based on a tight-binding model for a finite nanoribbon system with periodic boundary conditions. A pronounced Friedel-oscillation-like dependence of the coupling magnitude on the impurity position within the nanoribbon resulting from quantum size effects is found and investigated.

A simple thermodynamic description of the combined Einstein and elastic models.

A simple application of the Einstein model combined with an elastic description of the solid state is developed. The frequency of quantum oscillators has been assumed as volume dependent and elastic energy terms with a static character have been included to complete the description. Such an extension enables us to construct the complete thermodynamics.