Ab initio modelling of magnetic anisotropy in Sr3NiPtO6

Computational design of magnetic molecules and their environment using quantum chemistry, machine learning and multiscale simulations

Having served as a playground for fundamental studies on the physics of d and f electrons for almost a century, magnetic molecules are now becoming increasingly important for technological applications, such as magnetic resonance, data storage, spintronics and quantum information. All of these applications require the preservation and control of spins in time, an ability hampered by the interaction with the environment, namely with other spins, conduction electrons, molecular vibrations and electromagnetic fields. Thus, the design of a novel magnetic molecule with tailored properties is a formidable task, which does not only concern its electronic structures but also calls for a deep understanding of the interaction among all the degrees of freedom at play. This Review describes how state-of-the-art ab initio computational methods, combined with data-driven approaches to materials modelling, can be integrated into a fully multiscale strategy capable of defining design rules for magnetic molecules.

Magnetic anisotropy of iridium dimers on two-dimensional materials

The magnetic anisotropy energy of Ir₂ dimers on germanene with different adsorption sites and areal densities.

Crystal Structures and Low-Dimensional Ferromagnetism of Sodium Nickel Phosphates Na5Ni2(PO4)3·H2O and Na6Ni2(PO4)3OH

Two new sodium nickel phosphates, Na₅Ni₂(PO₄)₃·H₂O (I) and Na₆Ni₂(PO₄)₃OH (II), have been synthesized hydrothermally and characterized by synchrotron X-ray diffraction, electron diffraction, low-temperature thermodynamic and magnetic measurements, and ab initio calculations. Unlike the majority of Ni²⁺ compounds, I and II show predominant ferromagnetic exchange couplings. I crystallizes in the monoclinic space group P2₁/ n ( a = 14.0395(4) Å, b = 5.1847(14) Å, c = 16.4739(4) Å, β = 110.4186(14)°) and features chains of ferromagnetically coupled Ni²⁺ ions. In II with the orthorhombic space group Pcmb ( a = 7.5007(15) Å, b = 21.4661(4) Å, c = 7.1732(15) Å), the ferromagnetically coupled Ni²⁺ ions form dimers arranged on a spin ladder. Both compounds represent rare examples of quasi-one-dimensional ferromagnets. Structural features behind this unusual magnetic behavior are discussed.

Large magnetic anisotropy and strain induced enhancement of magnetic anisotropy in monolayer TaTe2

MAE of monolayer TaTe₂ under different strains ranges from 0% to 10%.