Coupling Phenomena in Magnetocaloric Materials

Waske, Anja; Dutta, Biswanath; Teichert, Niclas; Weise, Bruno; Shayanfar, Navid; Becker, Andreas; Hütten, Andreas; Hickel, Tilmann

doi:10.1002/ente.201800163

Cited by 16 publications

(7 citation statements)

References 113 publications

(218 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is also an excellent review by Entel et al [ 43 ] who discussed magnetic exchange interactions and stability of different magnetic states, ordering/disordering energies and martensite transformation in Heusler Ni-Mn-X (X = Ga, In, and Sn). Further, a comprehensive review of coupling phenomena in magnetocaloric materials was published recently by Waske et al [ 44 ]. As strong coupling effects in magnetocaloric materials are the key factor to achieve a large magnetic entropy change, Waske et al compiled results for atomic coupling, stress coupling, and magnetostatic coupling in a set of Heusler compounds including Ni

MnGa, Mn-rich Ni-Mn-Z (Z = Al, In, Sn, Sb) as well as other more complicated, e.g., quaternary materials.…”

Section: Introductionmentioning

confidence: 99%

An Ab Initio Study of Pressure-Induced Changes of Magnetism in Austenitic Stoichiometric Ni2MnSn

et al. 2021

View full text Add to dashboard Cite

We have performed a quantum-mechanical study of a series of stoichiometric Ni2MnSn structures focusing on pressure-induced changes in their magnetic properties. Motivated by the facts that (i) our calculations give the total magnetic moment of the defect-free stoichiometric Ni2MnSn higher than our experimental value by 12.8% and (ii) the magnetic state is predicted to be more sensitive to hydrostatic pressures than seen in our measurements, our study focused on the role of point defects, in particular Mn-Ni, Mn-Sn and Ni-Sn swaps in the stoichiometric Ni2MnSn. For most defect types we also compared states with both ferromagnetic (FM) and anti-ferromagnetic (AFM) coupling between (i) the swapped Mn atoms and (ii) those on the Mn sublattice. Our calculations show that the swapped Mn atoms can lead to magnetic moments nearly twice smaller than those in the defect-free Ni2MnSn. Further, the defect-containing states exhibit pressure-induced changes up to three times larger but also smaller than those in the defect-free Ni2MnSn. Importantly, we find both qualitative and quantitative differences in the pressure-induced changes of magnetic moments of individual atoms even for the same global magnetic state. Lastly, despite of the fact that the FM-coupled and AFM-coupled states have often very similar formation energies (the differences only amount to a few meV per atom), their structural and magnetic properties can be very different.

show abstract

MnGa, Mn-rich Ni-Mn-Z (Z = Al, In, Sn, Sb) as well as other more complicated, e.g., quaternary materials.…”

Section: Introductionmentioning

confidence: 99%

An Ab Initio Study of Pressure-Induced Changes of Magnetism in Austenitic Stoichiometric Ni2MnSn

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The nuclei stop to grow if the tip of the diamonds touch other phases, such as substrates or other martensite nuclei, as often an energetically unfavorable incoherent interface has to be formed. Thus, in thin films the thickness of the film defines the maximum size of a martensitic nucleus [ 22 ]. As the thicknesses of the ALs become smaller with increasing number of intercalations the maximum size of the martensite nuclei is reduced as well, leaving a lot of untransformed material in between the nuclei.…”

Section: Resultsmentioning

confidence: 99%

The Influence of Martensitic Intercalations in Magnetic Shape Memory NiCoMnAl Multilayered Films

Becker

Ramermann

Ennen

et al. 2021

Entropy

Self Cite

View full text Add to dashboard Cite

Hysteresis and transformation behavior were studied in epitaxial NiCoMnAl magnetic shape memory alloy thin films with varying number martensitic intercalations (MIs) placed in between. MIs consists of a different NiCoMnAl composition with a martensitic transformation occurring at much higher temperature than the host composition. With increasing number of intercalations, we find a decrease in hysteresis width from 17 K to 10 K. For a large difference in the layers thicknesses this is accompanied by a larger amount of residual austenite. If the thicknesses become comparable, strain coupling between them dominates the transformation process, which manifests in a shift of the hysteresis to higher temperatures, splitting of the hysteresis in sub hysteresis and a decrease in residual austenite to almost 0%. A long-range ordering of martensite and austenite regions in the shape of a 3D checker board pattern is formed at almost equal thicknesses.

show abstract

“…Some materials experience a change in entropy (Δs T ) when exposed to a magnetic field in an isothermal environment due to a phase change of either the first or second thermodynamic order [182][183][184]. When placed in an adiabatic environment instead, this magnetic-field-induced phase ADDITIVE MANUFACTURING FROM THE POINT OF VIEW OF MATERIALS… change produces a temperature change (ΔT ad ) in the material, leading to the common designation of this phenomenon as the magnetocaloric effect [185].…”

Section: Additive Manufacturing Of Magnetocaloric Materialsmentioning

confidence: 99%