Papers by Keyword: Fe-Pd

Abstract: The shape memory effect (SME) and magnetic shape memory effect (MSME) Fe-Pd thin film are using the film curvature method. The corresponding residual stress change due to theSME and MSME in Fe-Pd film is measuredduring thermal cycling and magnetic field changing. AFe-Pd thin film with a lateral composition gradient is deposited onto micromachined x7 cantilever beam arraysubstrate,such that each of the cantilever beams is coated with a film of different composition.There is abrupt stress change in only .1 at % Pd as the temperature of the film is cycled, and the corresponding stress change was measured as 0.16 GPa. The film with .4 at % Pd showsthe abrupt stress change at 0.7 Tesla, which means that the composition has the MSME.

Abstract: The effect of the partial substitution of Fe by Co and Mn on the structural and magnetic properties of Fe-Pd alloys has been investigated by means of calorimetric, magnetic and neutron diffraction measurements. The addition of Mn increases both the reversible and irreversible MT temperatures whereas the addition of Co causes the opposite effect, which points out that that the compositional dependence of the transformation temperatures of the Fe-Pd alloys is not related to the Pd amount but to the e/a concentration. Furthermore, it is shown that the appearance of the BCT phase is directly related to the tetragonality of the FCT phase. On the other hand, the amount of FCT martensite that irreversibly transforms into the undesirable BCT phase is considerably reduced by both the Co and Mn doping. The substitution of Fe by Co seems to be especially interesting for magnetic field-induce strains applications since both the magnetic anisotropy and the saturation magnetization of the Fe-Pd FCT martensite are considerably increased with the Co addition.

Abstract: Isolated nanoparticles composed of bcc-Fe and L10-FePd have been fabricated by successive deposition of Pd and Fe onto NaCl substrate cleaved in air, and their structural characterization has been performed by transmission electron microscopy (TEM). Alloy composition was varied by changing the deposited Fe thickness in the thickness range between 2 and 7.5 nm with respect to the fixed Pd thickness of 1 nm. Post-deposition annealing lead to a formation of dual phase nanocomposite particles with the L10-type ordered phase and the bcc-Fe phase within each particle. The particle size little changed on annealing at 873K, indicating that both alloying and atomic ordering reactions proceeded within each nanoparticle. The size of the bcc-Fe region in Fe/FePd nanoparticles was measured from TEM images and its relation to the change of the maximum energy product was discussed.