Multiscale Examination of Strain Effects in Nd-Fe-B Permanent Magnets

Want a better motor in your electric car, or windmill generator? Know your magnets. In a permanent magnet, local strain near grain-boundary interfaces plays a crucial role in determining the effective coercivity. The authors use both first-principles and micromagnetic calculations to examine strain effects in Nd-Fe-B, and find that in-plane shrinkage reduces its magnetocrystalline anisotropy. These results should stimulate interest in terms of tailoring microstructures, understanding the vast differences between molecular dynamics simulations, and spurring high-resolution experiments on local strain.