The magnetostructural transition and magnetocaloric properties in Fe0.6Mn0.4NiSi1−xAlx alloys

The Stockbargard – Bridgman method yielded single crystals Mn0.99Fe0.01As. The effect of an external magnetic field with an intensity of up to 10 T on phase transitions in the single crystal Mn0.99Fe0.01As is studied. It is established that the magnetostructural phase transition in Mn0.99Fe0.01As is accompanied by a change in the entropy ΔSm, which is due to the transformation of the crystal structure. At temperatures above the temperature of the magnetostructural transition Tu = 290 K, the existence of an unstable magnetic structure is obtained. The magnetocaloric characteristics of the material under study are determined by an indirect calculation method based on the Maxwell thermodynamic relations and the Clapeyron – Clausius equation.

Download Full-text

Magnetocaloric Properties of Low-Cost Fe and Sn Substituted MnNiSi-Based Alloys Exhibiting a Magnetostructural Transition Near Room Temperature

IEEE Transactions on Magnetics ◽

10.1109/tmag.2018.2832090 ◽

2018 ◽

Vol 54 (11) ◽

pp. 1-5

Author(s):

K. Deepak ◽

R. V. Ramanujan

Keyword(s):

Room Temperature ◽

Low Cost ◽

Magnetostructural Transition ◽

Magnetocaloric Properties

Download Full-text

Phase Transitions and Magnetocaloric Properties in MnCo1−xZrxGe Compounds

Advances in Condensed Matter Physics ◽

10.1155/2017/2683789 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

Anil Aryal ◽

Abdiel Quetz ◽

Sudip Pandey ◽

Igor Dubenko ◽

Shane Stadler ◽

...

Keyword(s):

Transition Temperature ◽

Ferromagnetic State ◽

Partial Substitution ◽

Cooling Power ◽

Martensitic Transition ◽

Ferromagnetic Transition ◽

Scanning Calorimetry ◽

Magnetostructural Transition ◽

Magnetocaloric Properties ◽

Single Transition

The structural, magnetic, and magnetocaloric properties of MnCo1-xZrxGe (0.01≤x≤0.04) have been studied through X-ray diffraction, differential scanning calorimetry, and magnetization measurements. Results indicate that the partial substitution of Zr for Co in MnCo1-xZrxGe decreases the martensitic transition temperature (TM). For x = 0.02, TM was found to coincide with the ferromagnetic transition temperature (TC) resulting in a first-order magnetostructural transition (MST). A further increase in zirconium concentration (x = 0.04) showed a single transition at TC. The MST from the paramagnetic to ferromagnetic state results in magnetic entropy changes (-ΔSM) of 7.2 J/kgK for ΔH = 5 T at 274 K for x = 0.02. The corresponding value of the relative cooling power (RCP) was found to be 266 J/kg for ΔH = 5 T. The observed large value of MCE and RCP makes this system a promising material for magnetic cooling applications.

Download Full-text

Magnetocaloric Properties and Magnetic Anisotropy by Tailoring Phase Transitions in NiMnGa Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.583.169 ◽

2008 ◽

Vol 583 ◽

pp. 169-196 ◽

Cited By ~ 23

Author(s):

Franca Albertini ◽

Massimo Solzi ◽

Antonio Paoluzi ◽

Lara Righi

Keyword(s):

Magnetic Anisotropy ◽

Magnetocaloric Effect ◽

Magnetic Transition ◽

Critical Temperatures ◽

First Order ◽

Magnetostructural Transition ◽

Thermomagnetic Analysis ◽

Magnetocaloric Properties ◽

Giant Magnetocaloric Effect ◽

Composition Changes

The giant magnetocaloric properties of NiMnGa alloys can be enhanced by suitable composition changes that make structural and magnetic transition temperatures to coincide. In this paper we report results on critical temperatures, magnetic anisotropy, and magnetocaloric effect in Ni- and Mn-rich alloys as a function of composition. A phenomenological phase diagram, useful for the identification by thermomagnetic analysis of magnetic and structural transitions in the vicinity of their coincidence, is proposed. Particular emphasis is given to the discussion of giant magnetocaloric effect of those alloys showing a first order magnetostructural transition, the method of its determination, and the potentialities for applications in the field of magnetic refrigeration.

Download Full-text

Realization of Magnetostructural Transition and Magnetocaloric Properties of Ni–Mn–Mo–Sn Heusler Alloys

Journal of Superconductivity and Novel Magnetism ◽

10.1007/s10948-018-4750-4 ◽

2018 ◽

Vol 32 (3) ◽

pp. 659-665

Author(s):

Ishfaq Ahmad Shah ◽

Najam ul Hassan ◽

Abudu keremu ◽

Saira Riaz ◽

Shahzad Naseem ◽

...

Keyword(s):

Heusler Alloys ◽

Magnetostructural Transition ◽

Magnetocaloric Properties

Download Full-text

First-principles and Monte Carlo study of magnetostructural transition and magnetocaloric properties ofNi2+xMn1−xGa

Physical Review B ◽

10.1103/physrevb.81.094411 ◽

2010 ◽

Vol 81 (9) ◽

Cited By ~ 100

Author(s):

V. D. Buchelnikov ◽

V. V. Sokolovskiy ◽

H. C. Herper ◽

H. Ebert ◽

M. E. Gruner ◽

...

Keyword(s):

Monte Carlo ◽

First Principles ◽

Monte Carlo Study ◽

Magnetostructural Transition ◽

Magnetocaloric Properties

Download Full-text

Influence of the transition width on the magnetocaloric effect across the magnetostructural transition of Heusler alloys

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2015.0306 ◽

2016 ◽

Vol 374 (2074) ◽

pp. 20150306 ◽

Cited By ~ 15

Author(s):

F. Cugini ◽

G. Porcari ◽

S. Fabbrici ◽

F. Albertini ◽

M. Solzi

Keyword(s):

Magnetocaloric Effect ◽

Heusler Alloys ◽

Entropy Change ◽

Large Temperature ◽

Transition Width ◽

Critical Temperatures ◽

Magnetostructural Transition ◽

Magnetocaloric Properties ◽

Clear Result ◽

Effective Use

We report a complete structural and magneto-thermodynamic characterization of four samples of the Heusler alloy Ni-Co-Mn-Ga-In, characterized by similar compositions, critical temperatures and high inverse magnetocaloric effect across their metamagnetic transformation, but different transition widths. The object of this study is precisely the sharpness of the martensitic transformation, which plays a key role in the effective use of materials and which has its origin in both intrinsic and extrinsic effects. The influence of the transition width on the magnetocaloric properties has been evaluated by exploiting a phenomenological model of the transformation built through geometrical considerations on the entropy versus temperature curves. A clear result is that a large temperature span of the transformation is unfavourable to the magnetocaloric performance of a material, reducing both isothermal entropy change and adiabatic temperature change obtainable in a given magnetic field and increasing the value of the maximum field needed to fully induce the transformation. The model, which is based on standard magnetometric and conventional calorimetric measurements, turns out to be a convenient tool for the determination of the optimum values of transformation temperature span in a trade-off between sheer performance and amplitude of the operating range of a material. This article is part of the themed issue ‘Taking the temperature of phase transitions in cool materials’.

Download Full-text