First some background
Permanent magnets, like the ones on your refrigerator, are ubiquitous in our lives; they are a key ingredient in computers, electric cars, wind-powered generators and other essential products. Super-strong permanent magnets made with neodymium and dysprosium are particularly important. But due to the cost and limited availability of those materials, scientists have been seeking alternative permanent magnet materials.
What did scientists discover?
Two properties that make for a good magnet are coercivity (its resistance to changes in magnetization) and remanence (how much magnetization is left after an external magnetic field is removed).
Scientists working at the MagLab have developed new methods for fabricating permanent magnets that exhibit these properties from two materials, manganese-gallium (Mn-Ga) and iron-cerium-boron (Fe-Ce-B).
They made Mn-Ga magnets by grinding the ingredients, pressing them together, then heating (or annealing) them under high magnetic fields. When tested for coercivity and remanence, the test samples exhibited enhanced remanence. This indicates that high magnetic field annealing can be used to tune magnetic properties.
The scientists also created promising permanent magnets out of Fe-Ce-B using other promising methods.
Why is this important?
These new fabrication techniques enhance the magnetic properties of these two new magnetic materials and could lead to new kinds of permanent magnets that are both very strong and cheap to make.
Who did the research?
Brown,D.R.1,2; Siegrist,T2; Besara,T2 Niu,R.M.2; Tan, X.H.2,3, Li,H.Y.3; Xu, H.3; Li W.D.3; Zhang,F3; and Han,K.2
1X-Energy, LLC.; 2National MagLab; 3Shanghai University;
Why did this research need the MagLab?
This work took advantage of the unique high magnetic field facilities and metallurgical expertise available at MagLab. Only at the MagLab can refractory heat treatment of materials take place under magnetic fields as high as 30 teslas.
Details for scientists
- View or download the expert-level Science Highlight, Permanent Magnet Materials without Neodymium and Dysprosium
- Read the full-length publication, High Magnetic Field Annealing of Mn-Ga Intermetallic Alloys, in MRS Advances
This research was funded by the following grants: G.S. Boebinger (NSF DMR-1157490); X.H.Tan (NSF China, 51471101)
For more information, contact Ke Han.