Magnetic, magnetocaloric and structural properties of manganese based monoborides doped with iron and cobalt – A candidate for thermomagnetic generators

Fries, Maximilian; Gercsi, Z.; Ener, Semih; Skokov, Konstantin P.; Gutfleisch, Oliver

doi:10.1016/j.actamat.2016.05.005

Cited by 27 publications

(16 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By further decreasing the Sn content, the magnetostructural transition can be shifted toward temperatures above 400 K and still a significant magnetization change is obtainable . This could make Ni‐Mn‐Sn‐Co an interesting material for the application of thermomagnetic power generation from waste heat …”

Section: Resultsmentioning

confidence: 99%

A Comparative Study on the Magnetocaloric Properties of Ni‐Mn‐X(‐Co) Heusler Alloys

Taubel

Gottschall

Fries

et al. 2017

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

We present a comprehensive study on three selected Heusler alloy systems. Ni-Mn-X(-Co) systems with X ¼ Al, In, Sn are compared with respect to the relevant magnetocaloric properties of their magnetostructural phase transition, namely martensitic transition temperature as well as its field dependence, magnetization change, and width of the thermal hysteresis. The latter one is strongly determining the reversibility of the magnetocaloric effect. Therefore the understanding of how to tailor it by extrinsic and intrinsic factors is of great importance. Our study of the magnetocaloric properties leads to the conclusion that the width of thermal hysteresis can be correlated to the magnetization change of the phase transition. Consequently, the adiabatic temperature change under cycling can largely vary despite similar values of isothermal entropy change for Ni-Mn-In-Co and Ni-Mn-Sn-Co. This result therefore shows the importance of tailoring sharpness, thermal hysteresis, and field dependence of the phase transition to achieve high values for the isothermal entropy change as well as a large magnetocaloric cooling effect in the different Heusler alloys.

show abstract

Section: Resultsmentioning

confidence: 99%

A Comparative Study on the Magnetocaloric Properties of Ni‐Mn‐X(‐Co) Heusler Alloys

Taubel

Gottschall

Fries

et al. 2017

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

show abstract

“…12,20,[24][25][26][27] In contrast, for systems without magnetostructural first-order transitions, the main strategy for improving ∆S M has been to increase the magnetic moment. [28][29][30] However, there exist several materials such as AlFe 2 B 2 , 31,32 Mn 5 Ge 3 , 33 CrO 2 , 34 MnCoP, 35 and MnB 35,36 which show promising magnetocaloric properties without any known first-order magnetostructural or magnetoelastic transitions. All of these materials have ∆S M values that are competitive with, or exceed that of Gd metal despite having gravimetric magnetic moments at saturation that are only between 30 % and 60 % as large.…”

Section: Introductionmentioning

confidence: 99%

“…38,39 However, this phenomenon was not explained, and MnB has not received much attention until recently. 35,36,[40][41][42] We use high-resolution temperature-dependent synchrotron powder diffraction and diffraction under a magnetic field to study the magnetostructural coupling in MnB and FeB. We find that despite the similarities between the two compounds, MnB shows dramatic anisotropic coupling between its lattice and magnetism while FeB does not. We employ density functional theory calculations to understand the origin of this magnetostructural coupling as a competition between manganese moment formation (and the associated volume effects) and B-B bonding.…”

Section: Introductionmentioning

confidence: 99%

“…While these challenges can often be alleviated using chemical tuning and device engineering, − a different solution that has gained popularity recently is to change the composition of a first-order material in order to weaken the magnetostructural coupling so that the transition becomes increasingly second-order. At the border between first- and second-order transitions, one may find a tricritical transition which has no hysteresis while maintaining a large Δ S M . ,,− In contrast, for systems without magnetostructural first-order transitions, the main strategy for improving Δ S M has been to increase the magnetic moment. − However, there exist several materials such as AlFe 2 B 2 , , Mn 5 Ge 3 , CrO 2 , MnCoP, and MnB , which show promising magnetocaloric properties without any known first-order magnetostructural or magnetoelastic transitions. All of these materials have Δ S M values that are competitive with, or exceed that of Gd metal despite having gravimetric magnetic moments at saturation that are only between 30% and 60% as large .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Magnetostructural Coupling Drives Magnetocaloric Behavior: The Case of MnB versus FeB

et al. 2019

View full text Add to dashboard Cite

Materials with strongly coupled magnetic and structural transitions can display a giant magnetocaloric effect, which is of interest in the design of energy-efficient and environmentally-friendly refrigerators, heat pumps, and thermomagnetic generators. There also exist however, a class of materials with no known magnetostructural transition that nevertheless show remarkable magnetocaloric effects. MnB has been recently suggested as such a compound, displaying a large magnetocaloric effect at its Curie temperature (570 K) showing promise in recovering low-grade waste heat using thermomagnetic generation. In contrast, we show that isostructural FeB displays very similar magnetic ordering characteristics, but is not an effective magnetocaloric. Temperature-and field-dependent diffraction studies reveal dramatic magnetoelastic coupling in MnB, which exists without a magnetostructural transition. No such behavior is seen in FeB. Furthermore, the magnetic transition in MnB is shown to be subtly first-order, albeit with distinct behavior from that displayed by other magnetocalorics with first-order transitions. Density functional theory-based electronic structure calculations point to the magnetoelastic behavior in MnB as arising from a competition between Mn moment formation and B-B bonding.

show abstract

“…Magnetic cooling and magnetic heat pumps are promising techniques due to their increased efficiencies, which can be 20 to 30% higher compared to conventional technologies [1][2][3][4][5][6][7]. In the reversed process, a temperature-induced magnetization change can be utilized to convert low-temperature waste heat (< 80 °C) into mechanical energy by thermomagnetic motors [8][9][10][11][12][13][14], which may further be converted into electricity. The utilization of the magnetocaloric effect (MCE) near room temperature could reduce the worldwide energy consumption and lower the emission of greenhouse gasses, due to significantly higher efficiencies and the use of environmentally friendly and abundantly available base materials.…”

Section: Introductionmentioning

confidence: 99%

Charge redistribution and the magnetoelastic transition across the first-order magnetic transition in (Mn,Fe) 2 (P,Si,B)

et al. 2018

View full text Add to dashboard Cite

We used temperature dependent high-resolution x-ray powder diffraction and magnetization measurements to investigate structural, magnetic and electronic degrees of freedom across the ferromagnetic magneto-elastic phase transition in Mn 1 Fe 1 P 0.6-w Si 0.4 B w (w = 0, 0.02, 0.04, 0.06, 0.08). The magnetic transition was gradually tuned from a strong first-order (w = 0) towards a second-order magnetic transition by substituting P by B. Increasing the B content leads to a systematic increase in the magnetic transition temperature and a decrease in thermal hysteresis, which completely vanishes for w = 0.08. Furthermore, the largest changes in lattice parameter across the magnetic transition occur for w = 0, which systematically becomes smaller approaching the samples with w = 0.08. Electron density plots show a strong directional preference of the electronic distribution on the Fe site, which indicates the forming of bonds between Fe atoms and Fe and P/Si in the paramagnetic phase. On the other hand, the Mn-site shows no preferred directions resembling the behaviour of a free electron gas. Due to the low B concentrations (w = 0 -0.08), distortions of the lattice are limited. However, even small amounts of B strongly disturb the overall topology of the electron density across the unit cell. Samples containing B show a strongly reduced variation in the electron density compared to the parent compound without B.

show abstract

Magnetic, magnetocaloric and structural properties of manganese based monoborides doped with iron and cobalt – A candidate for thermomagnetic generators

Cited by 27 publications

References 44 publications

A Comparative Study on the Magnetocaloric Properties of Ni‐Mn‐X(‐Co) Heusler Alloys

A Comparative Study on the Magnetocaloric Properties of Ni‐Mn‐X(‐Co) Heusler Alloys

Magnetostructural Coupling Drives Magnetocaloric Behavior: The Case of MnB versus FeB

Charge redistribution and the magnetoelastic transition across the first-order magnetic transition in (Mn,Fe) 2 (P,Si,B)

Contact Info

Product

Resources

About