Spin Orientation and Magnetostriction of Tb1−xDyxFe2 from First Principles
Dr Christopher Patrick, in collaboration with the University of Warwick, derived the first principle value of Tb1-xDyxFe2 for room-temperature applications by calculating the easy magnetization direction and magnetostriction as a function of composition and temperature.
Crystal-field coefficients were used, which were obtained from within density-functional theory to construct phenomenological anistropy and magnetoelastic constants. The temperature dependence of these constants was obtained from disordered-local-moment calculations of the rare-earth magnetic order parameter.
The researchers' calculations found the critical Dy concentration required to switch the magnetization direction at room temperature to be xc = 0.78, with magnetostrictions λ111 = 2700 and λ100 = −430 ppm, close to the Terfenol-D values.
The full paper is available to read in volume 14 of Physical Review Applied.