We present a robust, automatic high-throughput workflow for the calculation of magnetic ground state of solid-state inorganic crystals, whether ferromagnetic, antiferromagnetic or ferrimagnetic, and their associated magnetic moments within the framework of collinear spin-polarized Density Functional Theory. This is done through a computationally efficient scheme whereby plausible magnetic orderings are first enumerated and prioritized based on symmetry, and then relaxed and their energies determined through conventional DFT + U calculations. This automated workflow is formalized using the atomate code for reliable, systematic use at a scale appropriate for thousands of materials and is fully customizable. The performance of the workflow is evaluated against a benchmark of 64 experimentally known mostly ionic magnetic materials of non-trivial magnetic order and by the calculation of over 500 distinct magnetic orderings. A non-ferromagnetic ground state is correctly predicted in 95% of the benchmark materials, with the experimentally determined ground state ordering found exactly in over 60% of cases. Knowledge of the ground state magnetic order at scale opens up the possibility of high-throughput screening studies based on magnetic properties, thereby accelerating discovery and understanding of new functional materials.

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High-throughput prediction of the ground-state collinear magnetic order of inorganic materials using Density Functional Theory

In this paper we build a holographic model of paramagnetism/antiferromagnetism phase transition, which is realized by introducing two real antisymmetric tensor fields coupling to the background gauge field strength and interacting with each other in a dyonic black brane background. In the case without an external magnetic field and in low temperatures, the magnetic moments condense spontaneously in an antiparallel manner with the same magnitude and the time reversal symmetry is also broken spontaneously (if the boundary spatial dimension is more than 2, spatial rotational symmetry is broken spontaneously as well), which leads to an antiferromagnetic phase. In the case with the weak external magnetic field, the magnetic susceptibility density has a peak at the critical temperature and satisfies the Curie-Weiss law in the paramagnetic phase of antiferromagnetism. In the strong external magnetic field case, there is a critical magnetic field ${B}_{c}$ in the antiferromagnetic phase: when the magnetic field reaches ${B}_{c}$, the system will return into the paramagnetic phase by a second order phase transition.

Holographic model for the paramagnetism/antiferromagnetism phase transition

State-of-the-art many-body simulations can predict the magnetic ground state of over 100 materials from first principles, pushing the exploration and design of magnetic materials to a new era.

https://link.aps.org/pdf/10.1103/PhysRevX.11.011031

Benchmark for Ab Initio Prediction of Magnetic Structures Based on Cluster-Multipole Theory

The compounds ${\mathrm{BaDy}}_{2}{\mathrm{O}}_{4}$ and ${\mathrm{BaHo}}_{2}{\mathrm{O}}_{4}$ are part of a family of frustrated systems exhibiting interesting properties, including spin-liquid-type ground states, magnetic-field-induced phases, and the coexistence of short- and long-range magnetic order, with dominant one-dimensional correlations, which can be described as Ising ${J}_{1}\text{\ensuremath{-}}{J}_{2}$ zigzag chains along the $c$ axis. We have investigated polycrystalline samples of ${\mathrm{BaDy}}_{2}{\mathrm{O}}_{4}$ and ${\mathrm{BaHo}}_{2}{\mathrm{O}}_{4}$ with both neutron diffraction and neutron spectroscopy, coupled to detailed crystalline electric field calculations. The latter points to site-dependent anisotropic magnetism in both materials, which is corroborated by the magnetic structures we determined. The two systems show the coexistence of two different long-range orders: two double N\'eel $\ensuremath{\uparrow}\ensuremath{\uparrow}\ensuremath{\downarrow}\ensuremath{\downarrow}$ orders in the $ab$ plane with propagation vectors ${\mathbf{k}}_{1}=(\frac{1}{2},0,\frac{1}{2})$ and ${\mathbf{k}}_{2}=(\frac{1}{2},\frac{1}{2},\frac{1}{2})$ for ${\mathrm{BaDy}}_{2}{\mathrm{O}}_{4}$, and two distinct arrangements of simple N\'eel $\ensuremath{\uparrow}\ensuremath{\downarrow}\ensuremath{\uparrow}\ensuremath{\downarrow}$ orders along the $c$ axis, both with the propagation vector ${\mathbf{k}}_{0}=(0,0,0)$ for ${\mathrm{BaHo}}_{2}{\mathrm{O}}_{4}$. The order for both wave vectors in ${\mathrm{BaDy}}_{2}{\mathrm{O}}_{4}$ occurs at ${T}_{\mathrm{N}}=0.48\phantom{\rule{0.28em}{0ex}}\mathrm{K}$, while in ${\mathrm{BaHo}}_{2}{\mathrm{O}}_{4}$ the first order sets in at ${T}_{\mathrm{N}}\ensuremath{\sim}\phantom{\rule{3.33333pt}{0ex}}1.3\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ and the second one has a lower ordering temperature of 0.84 K. Both compounds show extensive diffuse scattering which we successfully modeled with a one-dimensional axial next-nearest neighbor Ising (ANNNI) model. In both materials, strong diffusive scattering persists to temperatures well below where the magnetic order is fully saturated.

/pdf/coexistence-of-magnetic-fluctuations-and-long-range-order-in-1lixdhvqcw.pdf

Coexistence of magnetic fluctuations and long-range order in the one-dimensional J 1 - J 2 zigzag chain materials BaDy 2 O 4 and BaHO 2 O 4

Molecular manganese fluorides were studied using quantum-chemical calculations at DFT and CCSD(T) levels and experimentally by matrix-isolation techniques. They were prepared by co-deposition of IR-laser ablated elemental manganese or manganese trifluoride with F2 in an excess of Ne, Ar, or N2 or with neat F2 at 5–12 K. New IR bands in the Mn–F stretching region are detected and assigned to matrix-isolated molecular MnFx (x = 1–3).

/pdf/a-combined-quantum-chemical-and-matrix-isolation-study-on-zv1p5wkh4z.pdf

A combined quantum-chemical and matrix-isolation study on molecular manganese fluorides

We present the classical antiferromagnet MnF2 as a perfect demonstration system for teaching a remarkably wide variety of neutron scattering concepts. The nature of antiferromagnetism and the magne...

/pdf/neutron-scattering-study-of-the-classical-antiferromagnet-13bikeqhyi.pdf

Neutron scattering study of the classical antiferromagnet MnF2: a perfect hands-on neutron scattering teaching courseSpecial issue on Neutron Scattering in Canada.

Z. YamaniZ. Yamani

Papers

Neutron scattering study of the classical antiferromagnet MnF2: a perfect hands-on neutron scattering teaching courseSpecial issue on Neutron Scattering in Canada.