Phase transitions and the magnetocaloric effect in Mn rich Ni–Mn–Ga Heusler alloys

Zhou, Xiaocheng; Kunkel, H. P.; Williams, Gwyn; Zhang, Shuihe; Desheng, Xue

doi:10.1016/j.jmmm.2006.01.029

Cited by 34 publications

(17 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This individual behavior is similar to that observed in some giant magnetocaloric materials222324 and Ni 2 In-type hexagonal compounds252627. It makes these particular alloys prospectively apply to magnetic refrigeration282930313233. Very recently, a giant MCE related to magneto-multistructural transformation was reported in annealed Ni 52 Mn 26 Ga 22 ribbon above room temperature, which is due to existence of an intermediate phase involving different modulated martensitic structures34.…”

supporting

confidence: 80%

Two successive magneto-structural transformations and their relation to enhanced magnetocaloric effect for Ni55.8Mn18.1Ga26.1 Heusler alloy

Kuangdi

Zhang

et al. 2015

Sci Rep

View full text Add to dashboard Cite

In the present work, two successive magneto-structural transformations (MSTs) consisting of martensitic and intermartensitic transitions have been observed in polycrystalline Ni55.8Mn18.1Ga26.1 Heusler alloy. Benefiting from the additional latent heat contributed from intermediate phase, this alloy exhibits a large transition entropy change ΔStr with the value of ~27 J/kg K. Moreover, the magnetocaloric effect (MCE) has been also evaluated in terms of Maxwell relation. For a magnetic field change of 30 kOe, it was found that the calculated value of refrigeration capacity in Ni55.8Mn18.1Ga26.1 attains to ~72 J/kg around room temperature, which significantly surpasses those obtained for many Ni-Mn based Heusler alloys in the same condition. Such an enhanced MCE can be ascribed to the fact that the isothermal entropy change ΔST is spread over a relatively wide temperature interval owing to existence of two successive MSTs for studied sample.

show abstract

supporting

confidence: 80%

Two successive magneto-structural transformations and their relation to enhanced magnetocaloric effect for Ni55.8Mn18.1Ga26.1 Heusler alloy

Kuangdi

Zhang

et al. 2015

Sci Rep

View full text Add to dashboard Cite

show abstract

“…[30] The Al and Ga atoms have three valence electrons each and the e/a ratio for the replacement of Ga with Al does not change. As discussed earlier, the lower martensite temperatures should not be interpreted on the basis of the e/a ratio alone, but using the electronic density-ofstate measurements.…”

Section: Al-containing Alloysmentioning

confidence: 99%

Structural and Magnetic Transitions in Fe-, Co-, and Al-Substituted Ni-Mn-Ga Ferromagnetic Shape Memory Alloys

Mathur

Singh

Chandrasekaran

et al. 2007

Metall Mater Trans A

View full text Add to dashboard Cite

Quaternary alloys based on Ni 50 Mn 30 Ga 20 (an off-stoichiometric Heusler alloy, Ni 2 MnGa), with an intended substitution of 10 at. pct Ni by Fe or Co and with a 5 at. pct substitution of Ga by Al, were prepared by vacuum arc melting and heat treated. The as-cast and heat-treated alloys were characterized for their structural, thermal, and magnetic properties. The saturation magnetization improved with the addition of ferromagnetic elements Fe or Co and decreased with the Al addition. All three of the substitutions lowered the martensite transformation temperature, due to a reduction in the electron-to-atom (e/a) ratio for the Fe/Co additions or due to the more open structure resulting from the lower atomic size, in the case of the Al substitutions. Martensite transformation studied through thermal and thermomagnetic analysis methods shows a single-stage transformation in the case of the Fe/Co substitutions, whereas the Al substitution resulted in a two-stage transformation.

show abstract

“…Most of the martensitic plates are parallel to each other and flows diagonally. Few martensitic plates are also found to cross the diagonal [24]. One martensite plate varies from the other one, which leads to rearrangement of the magnetic structure from a single domain to complex multiple magnetic domains.…”

Section: Micro-structural Studiesmentioning

confidence: 98%

Effect of Mn substitution on structural and magnetic properties of ferromagnetic shape memory alloys

Mahalakshmi

Kumar

Meiyappan

et al. 2016

Mechanics of Advanced Materials and Structures

View full text Add to dashboard Cite

The structure and the magnetic transitions have been investigated as a function of Mn in stoichiometric Ni 2 MnGa heusler alloys. Particular attention is paid to examine the linear increase of martensite transformation temperature on substituting Mn for Ga. It is observed that the martensite temperature increases and Curie temperature decreases with the effect of Mn content.Room-temperature magnetic measurements show the composition-dependent characteristics with decreasing magnetic saturation values and increasing coercivity values due to decrease in the magnetic exchange interaction strength with increasing Mn in place of Ga. The SEM image confirms that the Mn rich alloys have the martensitic plates.

show abstract

Phase transitions and the magnetocaloric effect in Mn rich Ni–Mn–Ga Heusler alloys

Cited by 34 publications

References 23 publications

Two successive magneto-structural transformations and their relation to enhanced magnetocaloric effect for Ni55.8Mn18.1Ga26.1 Heusler alloy

Two successive magneto-structural transformations and their relation to enhanced magnetocaloric effect for Ni55.8Mn18.1Ga26.1 Heusler alloy

Structural and Magnetic Transitions in Fe-, Co-, and Al-Substituted Ni-Mn-Ga Ferromagnetic Shape Memory Alloys

Effect of Mn substitution on structural and magnetic properties of ferromagnetic shape memory alloys

Contact Info

Product

Resources

About