For anyone interested in what they could be used for, but without time to read the article,
On a nano level, everything we store inside our devices is the result of the coordinated action of electrons. If these materials could be improved, it could mean higher efficiency, more storage within the same size of material, and less loss when data is accessed.
Because
...in [this] paper, scientists show that they can tune these materials very precicely in order to create specific directions of magnetism.
While the traditional ferromagnets we use today are fine in many ways, they aren’t ideal, and can introduce a blurring between separated bits of data known as crosstalk.
apparently it's one of those "technically correct but also obviously nonsense" things: there's no different type of electromagnetism, but specific materials can be magnetic in different ways, dimagnetic/ferromagnetic/paramagnetic, and the stuff the article is about seems to be at least the fourth kind... urgh