Large magnetocaloric effects in magnetic intermetallics: First-principles and Monte Carlo studies

Entel, P.; Gruner, Markus E.; Ogura, M.; Sokolovskiy, V. V.; Grünebohm, Anna; Arróyave, Raymundo; Uebayashi, Kazuhiko; Singh, Navdeep; Talapatra, Anjana; Duong, Thien; Acet, Mehmet; Çakır, Aslı

doi:10.1051/matecconf/20153302001

Cited by 2 publications

(1 citation statement)

References 40 publications

(51 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hereby, Cr is more efficient in stabilizing the FM Mn Y -Mn Z configuration, as can be seen in the ordering of ∆E. For one Co atom, u and d states are of the same energy in agreement to previous work [72], but ∆E increases to about 21, 50, 71, and 92 meV f.u. −1 for Co 2 , Cr 1 , Cr 1 /Co 1 , and Cr 2 , respectively.…”

Section: Discussion and Resultssupporting

confidence: 88%

Tuning the magnetic phase diagram of Ni-Mn-Ga by Cr and Co substitution

Schröter¹,

Herper²,

Grünebohm³

2021

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Ni-Mn-based Heusler alloys have a high technical potential related to a large change of magnetization at the structural phase transition. These alloys show a subtle dependence of magnetic properties and structural phase stability on composition and substitution by 3d elements and although they have been extensively investigated, there are still ambiguities in the published results and their interpretation. To shed light on the large spread of reported properties, we perform a comprehensive study by means of density functional theory calculations. We focus on Cr and Co co-substitution whose benefit has been predicted previously for the expensive Ni-Mn-In-based alloy and study the more abundant iso-electronic counterpart Ni-Mn-Ga. We observe that substituting Ni partially by Co and/or Cr enhances the magnetization of the Heusler alloy and at the same time reduces the structural transition temperature. Thereby, Cr turns out to be more efficient to stabilize the ferromagnetic alignment of the Mn spins by strong antiferromagnetic interactions between Mn and Cr atoms. In a second step, we study Cr on the other sublattices and observe that an increase in the structural transition temperature is possible, but depends critically on the short-range order of Mn and Cr atoms. Based on our results, we are able to estimate composition dependent magnetic phase diagrams. In particular, we demonstrate that neither the atomic configuration with the lowest energy nor the results based on the coherent potential approximation are representative for materials with a homogeneous distribution of atoms and we also predict a simple method for fast screening of different concentrations which can be viewed as a blueprint for the study of high entropy alloys. Our results help to explain the large variation of experimentally found materials properties.

show abstract

Section: Discussion and Resultssupporting

confidence: 88%

Tuning the magnetic phase diagram of Ni-Mn-Ga by Cr and Co substitution

Schröter¹,

Herper²,

Grünebohm³

2021

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

Basic Properties of Well‐Known Intermetallics and Some New Complex Magnetic Intermetallics

Entel

2017

Handbook of Solid State Chemistry

View full text Add to dashboard Cite

The structural, electronic, and magnetic properties of novel functional magnetic intermetallics, in particular some of the most prominent magnetic Heusler alloys, have been reviewed with emphasis on their complex magnetic behavior and nonergodic glassy features, in contrast to the well‐known properties ofTi‐NiandNi‐Alshape memory alloys. Calculational procedures have been listed throughout the text and the theoretical results have been compared with experimental findings where possible. The thermodynamic properties of a few systems (Ni–Co–Mn–In), which undergo a structural phase transformation of displacive nature in conjunction with a metamagnetic first‐order phase transition, have been discussed in detail. The importance of such magnetostructural phase transition together with the so‐called thermodynamic (kinetic) arrest phenomenon for the appearance of a giant magnetocaloric effect has been underlined. The list of references should allow bridging the gap between shape memory alloys such asTi–Ni(including recentab initiocalculations that explain the rapid decrease of the martensitic transformation temperature with disorder) and the “exotic properties” of the magnetic intermetallics.

show abstract

Large magnetocaloric effects in magnetic intermetallics: First-principles and Monte Carlo studies

Cited by 2 publications

References 40 publications

Tuning the magnetic phase diagram of Ni-Mn-Ga by Cr and Co substitution

Tuning the magnetic phase diagram of Ni-Mn-Ga by Cr and Co substitution

Basic Properties of Well‐Known Intermetallics and Some New Complex Magnetic Intermetallics

Contact Info

Product

Resources

About