Magnetic X-ray absorption fine-structure (XAFS) spectra have been measured for Ni-Mn alloys. The magnetic XAFS in the near-edge region (X-ray absorption near-edge structure, XANES) and X-ray magnetic circular dichroism (XMCD) of the Mn and Ni K-edge for Ni(1-x)Mn(x) (x = 0.25, 0.24 and 0.20) show that (i) the local magnetic structure around the Mn atom is quite different from that around the Ni...

The magnetocaloric effect that originates from the martensitic transition in the ferromagnetic Ni-Mn-Ga shape-memory alloy is studied. We show that this effect is controlled by the magnetostructural coupling at both the martensitic variant and magnetic domain length scales. A large entropy change induced by moderate magnetic fields is obtained for alloys in which the magnetic moment of the two ...

The goal of this study is to make selective etch possible for the next generation MEMS(microelectromechanical systems) devices that are composed Ni-Mn-Ga and silicon layers. Due tothe large magnetic-field-induced strains Ni-Mn-Ga, sensing actuating components can be fab-ricated in Other functional manufactured layer.Single crystalline alloys grown by using Bridgman vertical growth techniquehave...

Effects of ultra high magnetic field of both pulse and steady types on martensitic transformation have been studied, using Fe-Ni-Mn, Fe-Ni-Mn-C alloys with the supplemental tests on Fe-Ni-C and Fe-NiCo-Ti alloys. It is found that the martensitic transformation is induced at room temperature not only athermally but also isothermally either by pulse magnetic field or by steady magnetic field for ...

Ferromagnetic shape memory alloys (FSMAs), which are potential candidates for future technologies (i.e., actuators in robots), have been paid much attention their high work per volume and rapid response as external stimulation, such a magnetic field, is imposed. Among all the FSMAs, Ni–Mn–Ga-based were considered promising materials due to appropriate phase transformation temperatures ferromagn...

Temperature dependence of reversible magnetic shape memory effect and magnetization changes were studied in Ni49.7Mn29.1Ga21.2. The twinning stress, equivalent magnetic stress, switching field and maximum strain all increase with decreasing temperature. A 5–6% reversible strain is observed in the temperature range of 307–263 K and it sharply decreases to 1–2% at temperatures below 263 K. The ma...

Our previous work on ferromagnetic shape memory Ni50Mn28.7Ga21.3 demonstrates reversible compressive strains of ǫ = −4100μǫ along the [001] direction under the application of a magnetic field also along the [001] direction with no external orthogonal restoring force. The reversibility of the strains is due to internal bias stresses oriented orthogonal to the field. These results show promise fo...