We're setting MAE as our next predictive model target.
So far we have Curie temperature and magnetic moment. MAE makes sense as a next step because understanding this value is absolutely essential to permanent magnet design.
Coercivity is usually downstream of MAE. If a magnet can't stay a magnet, it's no good!
Materials with high magnetic anisotropy usually have high coercivity, that is, they are hard to demagnetize. These are called "hard" ferromagnetic materials and are used to make permanent magnets. For example, the high anisotropy of rare-earth metals is mainly responsible for the strength of rare-earth magnets.
I've attempted scraping some values from research papers but I haven't gotten very far very fast. Instead, I'm going to double down on searching for existing dataset and bringing them all together.
This paper describes the open Novamag database that has been developed for the design of novel Rare-Earth free/lean permanent magnets.
Novamag is funded by the European Union’s Horizon 2020 research and innovation programme.
It's really interesting that searching Google for Novamag, the database this paper introduces, returns no results.
It's strange. Are there actually two different databases out there, and only now when I'm going back to look for NovoMag did I also find Novamag?
Upon initial discovery, it looks like this is a great resource. The dataset comes with CIF data, saturation magnetization, MAE, exchange integrals, curie temperature, atomic spins. Very excited to dig into some of this after we make progress on an MAE model.
Principal Investigators:
James R. Chelikowsky(University of Texas at Austin)
Kai-Ming Ho and Cai-Zhuang Wang(Iowa State University)
David Sellmyer and XiaoShan Xu(University of Nebraska–Lincoln)
The project was supported by the National Science Foundation (NSF) through the Designing Materials to Revolutionize and Engineer our Future (DMREF) program (Award Numbers: 1729202, 1729288, 1729677).
Both NovoMag and Novamag use adaptive genetic algorithm (AGA) as their crystal structure algo, and are both focused on rare-earth free permanent magnets.
I wasn't able to find an easy download for the data from this source so I built a little scraper to download the ~3000 structures with their properties. This database is great because it comes with CIF crystal structure files.
This dataset includes 3819 materials scraped from https://magmat.herokuapp.com/, the Magnetic Materials Database. See https://www.novomag.physics.iastate.edu/structure-database for citations and more resources. I've cleaned the dataset to include the available magnetic materials (in CIF format) and their properties: magnetic_ordering, total_magnetic_moment [μ_B/cell], averaged_magnetic_moment [μ_B/atom], magnetic_polarization [T], formation_energy_(vs._elemental_phases) [meV/atom], formation_energy_above_hull [meV/atom], magnetic_curie_temperature [K], magnetic_anisotropy_constant,_k_^a-c [MJ/m^3], magnetic_easy_axis, magnetic_hardness_parameter,_κ, magnetic_anisotropy_constant,_k_^b-c [MJ/m^3], magnetic_anisotropy_constant,_k_^b-a [MJ/m^3], magnetic_anisotropy_constant,_k_^d-a [MJ/m^3]
33,657 materials, although I'm not sure how many have MAE data
North East Materials Database
Powered by advanced large language models, our project introduces a comprehensive materials database aimed at accelerating the discovery of new materials. This AI-driven platform offers open web-based access to vast collections of information on various materials, including magnetic and thermoelectric properties, all extracted and synthesized from scientific literature.
So far, I've seen data for Curie temperature, magnetization, coercivity, remanence, some incomplete crystal structure data like space group, formula, and maybe parameters but this is all sparse. Pretty good still. With some work, we could make something worthwhile.
Total number of entries in the MAGNDATA database: 2328
I haven't seen any property data for these, but they do have mCIF files which I haven't seen much of. I'm not exactly sure what we can do with that data but it could be useful.
There are also a lot of other tools offered by https://www.cryst.ehu.es/ that may be worth checking out.