Magnetic-Field-Induced Strain of Shape-Memory Alloy Fe 3 Pt Studied by a Capacitance Method in a Pulsed Magnetic Field

Yamazaki

Kodama

et al. 2007

jjap

Self Cite

Medium-density polyethylene (PE) thin films have been successfully prepared by the Langmuir-Blodgett technique. The absorbance obtained by the Fourier transform infrared spectroscopy (FT-IR) measurement was proportional to the number of deposited layers, indicating that the layer-by-layer deposition of PE films proceeded successfully. Using the Kelvin probe surface potential measurement, it was concluded that as-deposited PE films were positively charged due to the displacement of electrons from the film to a metal. Finally, an energy diagram of the alkane oligomer molecule C 30 H 62 was computed based on an ab initio molecular orbital calculation, and then the possibility of positive charging of the PE film was discussed.

Section: Introductionmentioning

confidence: 99%

Magnetic Field-Induced Strain of Ni–Co–Mn–In Alloy in Pulsed Magnetic Field

Yamazaki

Kodama

et al. 2007

jjap

Self Cite

“…As for a Fe-31.2%Pd (at.%) single crystal alloy, a strain of 0.4% has been observed in single-shot pulse fields at the fields of 12 kOe with a frequency of 80 Hz at 77 K, which is much lower than the martensite transformation temperature T M = 230 K [58]. With regard to the Fe 3 Pt single crystal alloy, an MFIS of 1.7% has been observed and a recoverable strain of about 0.6% has been induced in single-shot pulse fields at the fields of 20 kOe with a frequency of 160 Hz at 4.2 K in the martensite state (T M = 85 K) [59].…”

Section: Magnetic Field-induced Strain and Magnetostriction In Shape mentioning

confidence: 90%

Magneto-Structural Properties of Ni2MnGa Ferromagnetic Shape Memory Alloy in Magnetic Fields

Adachi

Kanomata

2013

Metals

Self Cite

Abstract:The purpose of this review was to investigate the correlation between magnetism and crystallographic structures as it relates to the martensite transformation of Ni 2 MnGa type alloys, which undergo martensite transformation below the Curie temperature. In particular, this paper focused on the physical properties in magnetic fields. Recent researches show that the martensite starting temperature (martensite transformation temperature) T M and the martensite to austenite transformation temperature (reverse martensite temperature) T R of Fe, Cu, or Co-doped Ni-Mn-Ga ferromagnetic shape memory alloys increase when compared to Ni 2 MnGa. These alloys show large field dependence of the martensite transformation temperature. The field dependence of the martensite transformation temperature, dT M /dB, is −4.2 K/T in Ni 41 Co 9 Mn 32 Ga 18 . The results of linear thermal strain and magnetization indicate that a magneto-structural transition occurred at T M and magnetic field influences the magnetism and also the crystal structures. Magnetocrystalline anisotropy was also determined and compared with other components of Ni 2 MnGa type shape memory alloys. In the last section, magnetic field-induced strain and magnetostriction was determined with some novel alloys. OPEN ACCESS

“…Fe-Pd alloy and Fe 3 Pt alloy are ferromagnetic shape memory alloys [6]. These alloys are useful in pulse fields which correspond to AC magnetic flux density [7,8]. The weakness of these MFIS alloys is lowness of the martensitic transition temperature T M .…”

Section: Introductionmentioning

confidence: 99%

Magnetic Circuit for the Magnetic Actuator and Electrical Generator by Means of Magnetostriction Alloy

Int.J.Soc.Mater.Eng.Resour.

Yagi

Noor

et al. 2012

Self Cite

Novel magnetic circuit, which is combined with AC and DC magnetic fields, has been developed for the actuator by means of magnetostriction alloys. This magnetic circuit is also useful for high field creation for the nano laboratory or micro laboratory. The material of the yoke of the circuit was 99.99% pure Iron (Fe) and two coils were used for AC magnetic flux density. In order to adjust the DC fields, few ferrite magnets were used. Using this circuit, the magnetic flux density up to 1 T was generated in an aperture of 6.0 mm width and 2.0×2.0 mm square.Terfenol-D, which shows large magnetostriction, was established into the aperture of the magnetic circuit and AC magnetic flux density were applied by flowing the current of the electricity into the coils. We designed two type actuators. One is the actuator under the atmospheric pressure. The magnetostriction of Terfenol-D in this actuator is 680 ppm, which corresponds 4.0 μm displacement for 20 V pp output from an audio amp as use of power supply. The minimum displacement is 2 nm in 1 mV, which indicates that this magnetic actuator can be useful for nano meter activations for nano science and technology. The other is the actuator, which is applied uniaxial stress to the Terdfenol-D. This is 20×20×20 mm size and the activation length is 11 μm.The electric power generation system was also designed by means of the magnetic flux density change due to the magnetostriction. With exerting an impulsive force of 80 N, 24 mW electricity was generated. This generator is considered to be useful for the generator for the sensors or auxiliary lights of motorcars and trains.