Effect of ageing on the martensitic transformation of Ni–Fe–Ga alloys

Santamarta, R.; Font, J.; Muntasell, J.; Masdeu, F.; Pons, J.; Cesari, E.; Dutkiewicz, J.

doi:10.1016/j.scriptamat.2005.11.062

Cited by 58 publications

(31 citation statements)

References 18 publications

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“…At low temperatures these alloys, such as Ni-Mn-Al, Ni-Fe-Ga and Co-Ni-Al 13 , which contain different quantities of nickel, produced martensitic transformations characterized by twins. The dimensional change process occurring in these alloys involves the movement of the twin boundary of the martensite in the direction that allows a greater alignment of the domains with respect to the applied magnetic field 3 .…”

Section: Discussionmentioning

confidence: 99%

Ultrasonic study of structural instabilities in nickel induced by magnetic fields

Moreno-Gobbi¹,

Moreno²,

Zamir³

2008

Mat. Res.

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The ultrasonic phase velocity was measured on a high purity nickel single crystal with a bias magnetic field in cooling and heating runs over the interval of temperatures from approximately 100 to 325 K. An evident anomaly of the phase velocity was observed in both branches of the temperature cycle. The temperature of the anomaly in the heating run was always greater than that in the cooling run, indicating the presence of a hysteretic mechanism. The observed changes are attributed to dimensional alignment of the nickel single crystal twins which are able to distort the crystalline network. The temperature of the anomalies and its hysteretic behavior depend on the synergy between the direction and strength of the magnetic field, the direction of the ultrasonic wave propagation, the internal friction between the domains and the crystallographic orientation. The frictions between magnetic domains that do not contribute to the velocity anomaly produce a hysteretic loop. The process can be easily inhibited by disorientation of the magnetic field.

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Section: Discussionmentioning

confidence: 99%

Ultrasonic study of structural instabilities in nickel induced by magnetic fields

Moreno-Gobbi¹,

Moreno²,

Zamir³

2008

Mat. Res.

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“…To characterize the magnetoresistance in the martensitic transformation range, we actually measured the temperature variation of the resistivity in zero and 5T 05008-p. 4 magnetic fields (inset Fig 5a) and also the continuous variation of the resistivity with magnetic field at two fixed temperatures, first in the martensite and the second in the austenitic phase for the as prepared and annealed Co2Al3 samples (Fig5b). Fig.5a) The temperature variation of the magnetiresistivity for samples annealed at 400 C. Inset: resistivity variation with temperature in zero and 5T; b) the variation of resistance with magnetic field for Co2Al3 samples AQ and annealed at 400 C, respectively.…”

Section: Magnetorezistive Effectmentioning

confidence: 98%

“…The huge magnetic field induced strain (MFIS) exhibited by the Ni2MnGa alloy [2] justified the increased interest in FSMAs with Heusler disordered B2 austenite structure. Further developments indicated the off-stoichiometric Ni-Fe-Ga alloys as good candidates to replace the brittle Ni-Mn-Ga [3,4,5] due to improved mechanical durability when experiencing a reversible austenite-martensite transformation.…”

Section: Introductionmentioning

confidence: 99%

“…This intrinsic magneto-thermodynamic phenomenon is related to the magnetic entropy associated with the spin structure of an alloy and its change under application of an external magnetic field [13]. Several rare earth based systems (Gd 5 (SiGe) 4 , DyMn 2 Ge, Gd RuGe 2, ) exhibiting magnetic and structural phase transitions occurring in the same temperature range, have been reported to show very large MCE [14].…”

Section: Introductionmentioning

confidence: 99%

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Magnetocaloric effect in Ni-Fe-Ga Heusler alloys with Co and Al substitutions

Ţolea

Sofronie

Crisan

et al. 2015

MATEC Web of Conferences

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Abstract. The functionality of the ferromagnetic shape memory alloys is related to the martensitic and magnetic order-disorder transformations, both of which may be tailored by doping with other elements or by suitable thermal treatments, so that alloys with concomitant (or sequential but close) structural and magnetic phase transitions may be obtained. Concerning the magnetocaloric applications, it is assumed that the thin melt-spun ribbons assure a more efficient heat transfer. In the present work we investigate the influence of Co and Al substitutions on magnetocaloric effect characteristics of NiFeGa in bulk and also in ribbons prepared by melt spinning method and subjected to different thermal treatments. X-ray diffraction, differential scanning calorimetry, magnetocaloric and magnetoresistive characterizations have been performed. The results highlight the differences between the bulk and the ribbons (both as prepared and annealed) and the role of substitutions.

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“…Curiously, the large magnetostriction of single crystalline Dy and Tb, which was found in 1970s, proved to be accompanied by a giant magnetoplastic deformation ( The amount of publications displayed in Fig.1 as the black columns are related to the other FSMA systems such as Fe-Pd [31,38,39], Fe 3 Pt [31,39], Ni-Mn-(Al, Sn, Sb, In) [18,[40][41][42][43], Co-Ni-(Al, Ga) [44][45][46][47][48] and Ni-Fe-(Al,Ga) [49][50][51][52][53]. The black part of the diagram in Fig.1 and overview articles [54,55] prove an increasing interest towards the alternative systems as well.…”

Section: Introductionmentioning

confidence: 99%

Magnetoelastic Nature of Ferromagnetic Shape Memory Effect

Chernenko

L’vov

2008

MSF

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Abstract. The giant magnetically-induced deformation of ferromagnetic shape memory alloys results from the magnetic field-induced rearrangement of twinned martensite under the magnetic field. This deformation is conventionally referred to as the magnetic-field-induced-strain (MFIS). The MFIS is comparable in value with the spontaneous deformation of crystal lattice during the martensitic transformation of an alloy. Although the first observations of MFIS were reported more than 30 years ago, it has got a world-wide interest 20 years later after the creation of the Ni-Mn-Ga alloy system with its practically important room-temperature martensitic structure and experimental evidence of the large magnetostriction. The underlying physics as well as necessary and sufficient conditions for the observation of MFIS are the main focus of this chapter. A magnetostrictive mechanism of the unusual magnetic and magnetomechanical effects observed in Ni-Mn-Ga alloys is substantiated and a framework of consistent theory of these effects is outlined starting from the fundamental conception of magnetoelasticity and the commonly known principles of ferromagnetism and linear elasticity theories. A reasonable agreement between the theoretical deductions and available experimental data is demonstrated and, in this way, a key role of magnetoelastic coupling in the magnetomechanical behavior of Ni-Mn-Ga alloys is proved. A correspondence of magnetostrictive mechanism to the crystallographic features of MFIS and the basic relationships of the thermodynamics of solids are discussed.

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Effect of ageing on the martensitic transformation of Ni–Fe–Ga alloys

Cited by 58 publications

References 18 publications

Ultrasonic study of structural instabilities in nickel induced by magnetic fields

Ultrasonic study of structural instabilities in nickel induced by magnetic fields

Magnetocaloric effect in Ni-Fe-Ga Heusler alloys with Co and Al substitutions

Magnetoelastic Nature of Ferromagnetic Shape Memory Effect

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