Phase analysis of NI-MN-SN ferromagnetic shape Memory alloys (original) (raw)
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Applied Physics A, 2020
The influence of Cu doping on structural and magnetic properties of Ni50-xMn36Sn14-yCux, y (x=0, 1,2 and y=1 at. %) ribbons has been investigated. The crystalline structures of the alloys were resolute by X-ray diffraction (XRD). It is found that the addition of Cu for Ni stabilizes austenite phase, whereas, replacing small amount of Cu for Sn stabilizes modulated martensite phase. Differential scanning calorimetry measurements have proved the characteristic transformation temperatures. The transformation temperatures generally rise as increasing the Cu content. Therefore, the magneto structural transition, analysed by vibrating sample magnetometry, is tuned by appropriate Cu doping in the alloys. Likewise, both martensitic and austenitic states exhibit ferromagnetic behaviour.
structural and magnetic characterization of martensitic Ni2MnGa ferromagnetic shape memory alloy
Ferromagnetic shape memory alloys (FSMAs) are keenly investigated due to their Shape Memory Effect (SME), high frequency response and large magnetic field-induced strain. Polycrystalline Ni53.2Mn24.6Ga22.1 alloy was synthesized by arc-melting technique. X-ray diffraction revealed that annealed alloy at 1073 K exhibit a well-defined 5M structure .Scanning Electron Microscope image confirms the twinned martensite plate with magnetic domain walls. It is worthy to notice that a high saturation magnetization of 65 (emu/g) and martensitic transformation temperature of TM (334 K) are found by Vibrating Sample Magnetometer and Differential Scanning Calorimetry.
Magnetic Investigations on Ni-Mn-Sn Ferromagnetic Shape Memory Alloy
Advanced Materials Research, 2008
Ferromagnetic shape memory alloy of nominal composition Ni50Mn35Sn15 has been investigated by magnetic and transport measurements. Clear signature of first order martensitic transition is observed over a region around 180 K in resistivity, dc magnetization and ac susceptibility data. Field-cooled and zero-field-cooled magnetizations diverge below the martensitic transition, signifying magneto-thermal irreversibility originating from pinning by variants. The sample shows large negative magneto-resistance (-25% at 90 kOe) in the region of martensitic transition, which was found to be highly irreversible. A clear correspondence between magnetoresistance and dc magnetization is observed above the field of technical saturation.
Ferromagnetic shape memory alloys (FSMAs) are keenly investigated due to their Shape Memory Effect (SME), high frequency response and large magnetic field-induced strain. Polycrystalline Ni 53.2 Mn24.6 Ga22.1 alloy was synthesized by arc-melting technique. X-ray diffraction revealed that annealed alloy at 1073 K exhibit awell-defined 5M structure .Scanning Electron Microscope image confirms the twinnedmartensite plate with magnetic domain walls. It is worthy to notice that a high saturation magnetization of 65 (emu/g) and martensitic transformation temperature of TM (334 K) are found by Vibrating Sample Magnetometer and Differential Scanning Calorimetry
Property optimization of Ferromagnetic Shape Memory alloys with respect to Cost
Ferromagnetic shape memory alloys (FSMAs) are the interesting materials exhibiting shape memory effect and magnetism simultaneously. They show magnetic field-induced strains at room temperature greater than any magnetostrictive, piezoelectric or electrostrictive material, and faster frequency response than temperature driven shape memory alloys. Among various FSMA materials, Ni-Mn-X (X =Ga, In, Sn, Sb) have gained considerable interest due to their multifunctional properties such as shape memory effect, magnetocaloric effect, magnetoresistance, etc., ssociated with first order martensite to austenite structural transition. FSMA spread its application in broad area from aerospace industry to medical application, but not vividly use; because of its high cost. Ni-Mn-Sn FSMAs shows low cost of manufacturing due to its low value of constituting element. This paper investigates the behavior of Ni-Mn-Sn Heusler FSMA by varying the weight percentage of Sn. Three alloys i.e. Mn50Ni50-xSnx (x = 5, 7.5, and 10) were produced as bulk polycrystalline ingots by arc melting. In order to identify structural phases X-ray diffraction (XRD) measurements were conducted at room temperature using Cu Ka radiation. By Differential Scanning Calorimetric (DSC) study it is found that, the transformation temperatures gradually decreases as increasing the Sn content, which shows it can apply in higher working temperature range than that of Ga-FSMAs..
Development of NiMnGa-based ferromagnetic shape memory alloy by rapid solidification route
Journal of Magnetism and Magnetic Materials, 2008
Rapid solidification route by melt spinning has been adopted for preparation of a Ni 52.5 Mn 24.5 Ga 23 (at %) ferromagnetic shape memory alloy in the form of ribbons. In the as-spun state, the ribbon revealed a predominant austenitic L2 1 structure in combination with martensitic feature as observed from x-ray diffraction studies. Transmission electron microscopic (TEM) evaluation showed these features in the form of martensitic plates. At low temperature, martensite to austenite transformation was exhibited by an increase in magnetization during heating cycle. The reverse effect was observed during cooling cycle. Annealing temperature and magnetising field was also found to effect this transformation.
Analysis of Martensitic Transformation in Ni-Mn-Sn FSMA
2012
Ferromagnetic shape memory alloys (FSMA) are a new class of potential multifunctionalmaterials with advancement over the conventional heat-driven shape memory alloys due to their exceptional properties. FSMAs can be controlled by magnetic field have attracted considerableattention as a type of magnetic actuator materials. Among the Heusler alloys that exhibitmagnetic shape memory effect, the most extensively studied are those of the Ni-Mn-Ga system.However, to overcome some of the problems related to practical application, such as the highcost of gallium and the low martensitic transformation temperature that they usually present, thesearch for Ga-free alloys has been recently attempted. This paper aims to represent the behavior of Ga free Ni-Mn-Sn Heusler FSMA by varying the weight percentage of Sn. Three alloys i.e.Mn50 Ni50-xSnx (x = 5, 7.5, and 10) were produced as bulk polycrystalline ingots by arc melting.The structural austenite-martensite transformation was checked by Differ...
Study of the martensitic transition in Ni-Mn-Sn-Ti ferromagnetic shape memory alloys
Matéria (Rio de Janeiro)
In the present work, mechanical spectroscopy measurements as a function of temperature and strain have been performed in (at.%) Ni 50 Mn 37 Sn 13-x Ti x (x=0, 0.5 and 2) ferromagnetic shape memory alloys in order both to study martensitic transition phenomenon and also to determine its temperature of appearance. For mechanical spectroscopy measurements, a five elements piezoelectric device recently developed has been used. In addition, other characterization techniques as, differential thermal analysis and superconducting quantum interference magnetic spectroscopy, were also used. Besides, relaxation processes near the martensitic transition temperature have been also observed.
Ferromagnetic shape memory alloys: structural and thermal properties
IOP Conference Series: Materials Science and Engineering, 2010
The most extensively studied Heusler alloys are those based on the Ni-Mn-Ga system. However, to overcome the high cost of Gallium and the usually low martensitic transformation temperature, the search for Ga-free alloys has been recently attempted, particularly, by introducing In, Sn or Sb. In this work, two alloys (Mn50Ni35.5In14.5 and Ni50Mn35In15) have been obtained by melt spinning. We outline their structural and thermal behaviour. Mn50Ni35.5In14.5 alloy has the transformation above room temperature whereas Ni50Mn35In15 does not have this transformation in the temperature range here analyzed.