Elastic properties of rare-earth-iron compounds

Abstract

Ultrasonic velocities have been measured and used to determine the elastic moduli of the highly magnetostrictive compounds: TbFe2, TbFe3, and ErFe2. A huge ΔE effect of 90% has been calculated for TbFe2 from our static stress-strain data.

Development of highly magnetostrictive composites for applications in magnetomechanical torque sensors

“…where < is a coefficient reflecting the rate of approach and W is the elastic energy generated equations by applied stress and causing the unpinning of domain walls. Combining (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and (7-21) with M = M,.,+ Min, the following equation is obtained =~(M~~-Mi~)+c dW~~( M~n -Min) (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) , The elastic energy is the product of stress and strain and is given by dW =adc/E (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23) where E is the Young's modulus of material. Then equation (7)(8)(9)(10)(11)…”

“…Combining (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25), the change of magnetization with stress can be expressed by dM=~(l-c)(M~-MiK)d~+c"dMa E2 (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26) 7.3. Extension of the model under uniaxial stress to torsional stresses If a rod (or a ring) is subjected to torque z in the plane normal to its axis, the torsion can be decomposed into biaxial stresses, as shown in Fig.7-4.…”

“…For torsional stress, the total elastic energy is the sum of elastic energy caused by the compressive and tensile stresses, (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23) The law of approach in this case is expressed by…”

Nuclear resonance fluorescence from the 58keV level in159Tb

“…The results for Tb in GdF% are given in Figure 8. [16] and a= 2,56-10-8 cm for the average distance of the atoms, the DBF's to be expected were calculated. The curve in Figure 8 is the result of this approximation and is in good agreement with the experimental data.…”

Tb0.3Dy0.7Fe1.92 nanoflakes prepared by surfactant-assisted high energy ball milling

“…The giant magnetostrictive material Terfenol-D with the cubic Laves phase was first developed by the Naval Surface Warfare Center in the early 1970s [1]. It exhibits large magnetostriction, high Curie temperature, large magneto-mechanical coupling coefficient and rapid frequency response.…”