scholarly journals Magnetic and Magnetostrictive Properties of Ni50Mn20Ga27Cu3 Rapidly Quenched Ribbons

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5126
Author(s):  
Mihaela Sofronie ◽  
Mugurel Tolea ◽  
Bogdan Popescu ◽  
Monica Enculescu ◽  
Felicia Tolea
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Thermal Treatment ◽  
Austenite Phase ◽  
Transformation Temperatures ◽  
Strain Measurements ◽  
Rapid Solidification Technique ◽  
Phase Transition Temperatures ◽  
Ferromagnetic Shape Memory ◽  
Curie Temperatures

The influence of the rapid solidification technique and heat treatment on the martensitic transformation, magnetic properties, thermo- and magnetic induced strain and electrical resistivity is investigated for the Cu doped NiMnGa Heusler-based ferromagnetic shape memory ribbons. The martensitic transformation temperatures are unexpectedly low (below 90 K—which can be attributed to the disordered texture as well as to the uncertainty in the elements substituted by the Cu), preceded by a premartensitic transformation (starting at around 190 K). A thermal treatment slightly increases the transformation as well as the Curie temperatures. Additionally, the thermal treatment promotes a higher magnetization value of the austenite phase and a lower one in the martensite. The shift of the martensitic transformation temperatures induced by the applied magnetic field, quantified from thermo-magnetic and thermo-magnetic induced strain measurements, is measured to have a positive value of about 1 K/T, and is then used to calculate the transformation entropy of the ribbons. The magnetostriction measurements suggest a rotational mechanism in low fields for the thermal treated samples and a saturation tendency at higher magnetic fields, except for the temperatures close to the phase transition temperatures (saturation is not reached at 5 T), where a linear volume magnetostriction cannot be ruled out. Resistivity and magnetoresistance properties have also been measured for all the samples.

The Phase Transformation and Magnetic Properties in Ni-Mn-In Alloys

2013 ◽  
Vol 712-715 ◽  
pp. 54-57 ◽  
Author(s):  
Hai Le Yan ◽  
Zong Bin Li ◽  
Chun Yang Zhang ◽  
Yu Dong Zhang ◽  
Claude Esling ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Transformation ◽  
Structural Transition ◽  
Alloy Composition ◽  
Ferromagnetic Shape Memory Alloys ◽  
Scanning Calorimetry ◽  
Phase Transition Temperatures ◽  
Ferromagnetic Shape Memory ◽  
Curie Temperatures ◽  
Magnetization Change

The phase transformation and magnetic properties of Heusler-type Ni50Mn50-xInx(x=10~16) ferromagnetic shape-memory alloys have been systemically investigated by differential scanning calorimetry and vibrating sample magnetometry. It is found that the phase transition temperatures show a linear relationship with the In concentration and the curie temperatures of austenite phases are not sensitive to the alloy composition. The existence of large magnetization change during the magneto-structural transition is the origin of magnetic-field-induced transformation effect.

Martensitic Transformation and Shape Memory Effect of Ni53.25Mn21.75Ga25 Ferromagnetic Shape Memory Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 1504-1507
Author(s):  
Hai Bo Wang ◽  
Shang Shen Feng ◽  
Pei Yang Cai ◽  
Yan Qiu Huo
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Parent Phase ◽  
Transformation Strain ◽  
Scanning Calorimetry ◽  
Reversible Transformation ◽  
Ferromagnetic Shape Memory

The martensitic transformation, crystalline structure, microstructure and shape memory effect of the Ni53.25Mn21.75Ga25 (at.%) alloy are investigated by means of Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD), Transmission Electron Microscope (TEM) and the standard metal strain gauge technique. The XRD results showed that the Ni53.25Mn21.75Ga25 alloy is composed of cubic parent phase at room temperature. TEM observation proved that the typical twin martensite is tetragonal structure and tweed-like contrast which is typical image for the parent phase. A large reversible transformation strain, about 0.54%, is obtained in this undeformed polycrystalline alloy due to martensitic transformation and its reverse transformation. This transformation strain is also increased to 0.65% by the external magnetic field. It is believed that the effect of the magnetic field on the preferential orientation of martensitic variants increases the transformation strain.

Martensitic Transformation of Ni-Mn-Ga Alloys under Magnetic Field and Hydrostatic Pressure

2006 ◽  
Vol 512 ◽  
pp. 189-194 ◽  
Author(s):  
Jae Hoon Kim ◽  
Takashi Fukuda ◽  
Tomoyuki Kakeshita
Keyword(s):  
Magnetic Field ◽  
Hydrostatic Pressure ◽  
Martensitic Transformation ◽  
Applied Magnetic Field ◽  
Transformation Temperature ◽  
Intermediate Phase ◽  
Parent Phase ◽  
Clapeyron Equation ◽  
Transformation Temperatures ◽  
The Magnetic Field

The effects of magnetic field and hydrostatic pressure on martensitic transformation have been systematically investigated by using Ni2MnGa, Ni2.14Mn0.84Ga1.02, and Ni2.14Mn0.92Ga0.94, which exhibit P(parent phase)-I(intermediate phase)-10M, P-14M-2M, and P-2M transformation, respectively. The following results were obtained. (i) The P-I transformation temperature does not change by magnetic field. (ii) The I-10M and the P-14M transformation temperatures decrease under applied magnetic field up to 0.8 MA/m and 0.4 MA/m, respectively, and then increase with increasing applied magnetic field higher than those fields. (iii) The 14M-2M transformation temperature increases under a magnetic field up to 0.4 MA/m and decreases under magnetic field up to 0.8 MA/m and then increases again when the magnetic field becomes higher than 0.8 MA/m. (iv) The P-2M transformation temperature increases linearly with increasing applied magnetic field. (v) All transformation temperatures increase linearly with increasing hydrostatic pressure. The experimental results mentioned above (i)~(iv) under magnetic field can be well explained by using the Clausius-Clapeyron equation.

Effect of Constant-Strain Aging on Microstructure, Martensitic Transformation and Magnetic Property of Ni53Mn23.5Ga23.5 Ferromagnetic Shape Memory Alloy

2014 ◽  
Vol 1015 ◽  
pp. 114-118
Author(s):  
G.F. Dong
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Curie Temperature ◽  
Shape Memory ◽  
Aged Sample ◽  
Ferromagnetic Shape Memory Alloy ◽  
Solution Treated ◽  
Treated Sample ◽  
Ferromagnetic Shape Memory

The effect of constant-strain aged and unaged on microstructure, martensite transformation, Curie temperature and magnetic field induction strain of Ni53Mn23.5Ga23.5ferromagnetic shape memory alloy was investigated in detail. The results show that reverse martensitic transformation temperatures of constant-strain aged sample slowly decrease, which martensitic transformation temperatures almost unchanged. In addition, Curie temperature of constant-strain aged sample is almost maintains consistent with solution-treated sample, but slowly increases saturation magnetization of constant-strain aged sample than solution-treated sample. Finally, the sample of constant-strain aged sample showed a larger magnetic field induction strain of 402 ppm.

The Stability of Magnetic-Field-Induced Strain in a NiMnGa Ferromagnetic Shape Memory Alloy

2005 ◽  
Vol 475-479 ◽  
pp. 2025-2028
Author(s):  
Feng Chen ◽  
Zhiyong Gao ◽  
Wei Cai ◽  
Lian Cheng Zhao
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Twin Boundary ◽  
Boundary Mobility ◽  
Martensitic Transformation Temperature ◽  
Ferromagnetic Shape Memory Alloy ◽  
Field Cycling ◽  
The Stability ◽  
Increasing Temperature ◽  
Ferromagnetic Shape Memory

The stability of magnetic field induced strain (MFIS) in Ni52Mn24Ga24 single crystal under temperature and magnetic field cycling is investigated and the corresponding micro-mechanism is also discussed. It shows that the saturated MFIS is very sensitive to temperature. Below martensitic transformation temperature(Tm), with increasing temperature, the saturated MFIS increases almost linearly. Besides, the saturated MFIS initially decreases with increasing the field cycling number less than four times, then does not change with further increasing the number of field cycles. The decrease of saturated MFIS can be attributed to the decrease of twin boundary mobility, which is related to the crystal defect introduced by immigration of twin boundary under field cycling.

Intrinsic Position Sensing of a Ni-Mn-Ga Microactuator

2008 ◽  
Author(s):  
Daniel Auernhammer ◽  
Manfred Kohl ◽  
Berthold Krevet ◽  
Makoto Ohtsuka
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Martensitic Transformation ◽  
Inhomogeneous Magnetic Field ◽  
Ferromagnetic Transition ◽  
Ferromagnetic Shape Memory Alloy ◽  
Position Sensing ◽  
Double Beam ◽  
Ferromagnetic Shape Memory ◽  
Magneto Resistance

This paper presents an investigation of the intrinsic magnetoresistance of a ferromagnetic shape memory alloy (FSMA) microactuator for position sensing. The microactuator is designed as a double-beam cantilever of a polycrystalline Ni-Mn-Ga thin film, which exhibits both, a martensitic transformation in the temperature range 333–359 K and a ferromagnetic transition at about 370 K. The microactuator is placed in the inhomogeneous magnetic field of a miniature Nd-Fe-B magnet causing a mixed thermo-magneto-resistance effect upon actuation. The maximum in-plane magnetic field is about 0.38 Tesla. In this case, the maximum magnetoresistance (MR) is 0.19%.

scholarly journals Magnetoresistance and Thermal Transformation Arrest in Pd2Mn1.4Sn0.6 Heusler Alloys

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2308 ◽  
Author(s):  
Xiao Xu ◽  
Hironari Okada ◽  
Yusuke Chieda ◽  
Naoki Aizawa ◽  
Daiki Takase ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Curie Temperature ◽  
Field Dependence ◽  
Magnetic Field Dependence ◽  
Thermal Transformation ◽  
Heusler Alloys ◽  
Parent Phase ◽  
Electric Resistivity ◽  
Transformation Temperatures

The magnetization, electric resistivity, and magnetoresistance properties of Pd 2 Mn 1 . 4 Sn 0 . 6 Heusler alloys were investigated. The Curie temperature of the parent phase, martensitic transformation temperatures, and magnetic field dependence of the martensitic transformation temperatures were determined. The magnetoresistance was investigated from 10 to 290 K, revealing both intrinsic and extrinsic magnetoresistance properties for this alloy. A maximum of about − 3 . 5 % of intrinsic magnetoresistance under 90 kOe and of about − 30 % of extrinsic magnetoresistance under 180 kOe were obtained. Moreover, the thermal transformation arrest phenomenon was confirmed in the Pd 2 Mn 1 . 4 Sn 0 . 6 alloy, and an abnormal heating-induced martensitic transformation (HIMT) behavior was observed.

scholarly journals Martensitic Transformation and Metamagnetic Transition in Co-V-(Si, Al) Heusler Alloys

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 226
Author(s):  
Kousuke Nakamura ◽  
Atsushi Miyake ◽  
Xiao Xu ◽  
Toshihiro Omori ◽  
Masashi Tokunaga ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Spontaneous Magnetization ◽  
Heusler Alloys ◽  
Parent Phase ◽  
Entropy Change ◽  
Ferromagnetic State ◽  
Martensite Phase ◽  
Reverse Martensitic Transformation ◽  
Curie Temperatures

This study investigates the crystal structure, martensitic transformation behavior, magnetic properties, and magnetic-field-induced reverse martensitic transformation of Co64V15(Si21–xAlx) alloys. It was found that by increasing the Al composition, the microstructure changes from the martensite phase to the parent phase. The crystal structures of the martensite and parent phases were determined as D022 and L21, respectively. Thermoanalysis and thermomagnetization measurements were used to determine the martensitic transformation and Curie temperatures. Both the ferromagnetic state of the parent phase and that of the martensite phase were observed. With the increasing Al contents, the martensitic transformation temperatures decrease, whereas the Curie temperatures of both the martensite and parent phases increase. The spontaneous magnetization and its composition dependence were also determined. The magnetic-field-induced reverse martensitic transformation of a Co64V15Si7Al14 alloy under pulsed high magnetic fields was observed. Moreover, using the results of the DSC measurements and the pulsed high magnetization measurements, the temperature dependence of the transformation entropy change of the Co-V-Si-Al alloys was estimated.

EFFECT OF AGING UNDER COMPRESSIVE STRESS ALONG [100] IN Co–Ni–Ga SINGLE CRYSTALS

2009 ◽  
Vol 02 (02) ◽  
pp. 83-86 ◽  
Author(s):  
C. PICORNELL ◽  
J. PONS ◽  
E. CESARI ◽  
Y. I. CHUMLYAKOV ◽  
J. DUTKIEWICZ
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Critical Stress ◽  
Parent Phase ◽  
Ferromagnetic Shape Memory Alloy ◽  
Slow Recovery ◽  
Transformation Temperatures ◽  
Two Stages ◽  
Ferromagnetic Shape Memory ◽  
Pseudoelastic Behavior

The pseudoelastic behavior of a Co 49 Ni 21 Ga 30 ferromagnetic shape memory alloy under compression along [100] has been studied in the temperature range 300–500 K. In such a crystals, the effect of aging under a constant stress close to the critical stress to induce the martensitic transformation, produces its separation in two stages. This is due to the different ordering behavior of parent and martensite phases under aging. Increasing order of parent phase leads to a decrease of transformation temperatures, which in return leads to an increase in critical stress to induce the transformation. Aging of martensite produces its stabilization — increase in transformation temperatures. It is remarkable that this stabilization has a very slow recovery, as compared to other alloys systems, such as Cu-based shape memory alloys.

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