Non-Joulian magnetostrictive materials and method of making the same
View Patent ↗The invention relates to non-Joulian magnetostriction (NJM) materials comprising transition metals, such as iron alloy magnets with non-Joulian magnetostriction (NJM). The invention also relates to reversibly linear non-dissipative transition metals magnets. The materials are capable of simultaneously large actuation in longitudinal and transverse directions, without simultaneous heat loss. The invention relates as well to methods of making non-Joulian magnetostriction (NJM) materials.
1. An actuator comprising a material comprising iron and a group 13 or 14 element, wherein the total volume of the material is capable of changing when the material is placed in a magnetic field;
wherein the actuator responds to a change in the total volume of the material.
2. The actuator of claim 1 , wherein the group 13 or 14 element is selected from the group consisting of aluminum, gallium, germanium, and silicon.
3. The actuator of claim 1 , wherein the concentration of transition metal in the material is between 60 to 100%.
4. The actuator of claim 1 , wherein the concentration of transition metal in the material is between 60 to 99.9%.
5. The actuator of claim 1 , wherein the volume change is an increase.
6. The actuator of claim 1 , wherein the volume change is a decrease.
7. The actuator of claim 1 , wherein the material is a magnet.
8. The actuator of claim 1 , wherein the material is ferromagnetic.
9. The actuator of claim 1 , wherein the material is a crystalline transition metal alloy of cubic crystal symmetry.
10. The actuator of claim 1 , comprising about 73.9% iron and about 26.1% gallium.
11. The actuator of claim 1 , comprising about 82.9% iron and about 17.1% gallium.
12. The actuator of claim 1 , wherein the material is crystalline and the volume change is due to dimensional strains of different relative magnitude along the different directions of the crystalline lattice of the material.
13. The actuator of claim 12 , wherein the relative magnitude of the dimensional strains is between 0.1 to 3000 ppm at room temperature.
14. The actuator of claim 12 , wherein the maxima of longitudinal dimensional strain occurs along any crystal direction where longitudinal magnetostriction means measured strain is along applied magnetic fields.
15. The actuator of claim 12 , wherein the relative magnitude of the dimensional strains is between 0.1 to 3000 ppm in the transverse directions at room temperature.
16. The actuator of claim 12 , wherein the maxima of transverse dimensional strains could occur along any crystal direction, where transverse magnetostriction means measured strain is perpendicular to the applied magnetic fields.
17. The actuator of claim 12 , wherein the maxima of longitudinal dimensional strain occurs along the easy directions of the crystalline lattice.
18. The actuator of claim 1 , wherein the material is crystalline and the volume change is due to dimensional strains of similar relative magnitude along the different directions of the crystalline lattice of the material.
19. The actuator of claim 18 , wherein the relative magnitude of the dimensional strains is between 0.1 to 3000 ppm.
20. The actuator of claim 18 , wherein the maxima of longitudinal dimensional strain occurs along the easy directions of the crystalline lattice.
21. The actuator of claim 1 , wherein the volume change results in a heat loss of about 0 J as the magnet is cycled in magnetic fields.
22. The actuator of claim 1 , wherein the material has a crystalline structure and exhibits plane-parallel micromagnetic cellular bands along the <100> type crystal direction.
23. The actuator of claim 22 , wherein the cells have nanoscale magnetic gradients within.