Fundamental aspects of symmetry and order parameter coupling for martensitic transition sequences in Heusler alloys

Carpenter, Michael A.; Howard, Christopher

doi:10.1107/s2052520618012970

Cited by 16 publications

(3 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The formalities of how this coupling leads to the observed pattern have been set out in full in the literature (see, for example, [28]). The structural/electronic order parameter, Q E , has the symmetry properties of irreducible representation Γ + 3 of the parent L2 1 cubic state with space group Fm 3m and couples bilinearly with tetragonal and orthorhombic shear strains, i.e., as λeQ [7,8,29]. Here, softening and stiffening of the combination of elastic constants C 11 -C 12 arises by bilinear coupling between Q E and the symmetry breaking shear strain of DO 22 -type tetragonal state (space group I4/mmm, con rmed by the diffraction pattern shown in gure S1).…”

Section: Resultsmentioning

confidence: 99%

Coupling between phase transitions and glassy magnetic behaviour in Heusler alloy Ni₅₀Mn₃₄In₈Ga₈

Zhang

Lou

Zhou

et al. 2020

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

The transition sequence in the Heusler alloy Ni50Mn34In8Ga8 has been determined from measurements of elasticity, heat flow and magnetism to be paramagnetic austenite → paramagnetic martensite → ferromagnetic martensite at ∼335 and ∼260 K, respectively, during cooling. The overall pattern of elastic stiffening/softening and acoustic loss is typical of a system with bilinear coupling between symmetry breaking strain and the driving structural/electronic order parameter, and a temperature interval below the transition point in which ferroelastic twin walls remain mobile under the influence of external stress. Divergence between zero-field-cooling and field-cooling determinations of DC magnetisation below ∼220 K indicates that a frustrated magnetic glass develops in the ferromagnetic martensite. An AC magnetic anomaly which shows Vogel–Fulcher dynamics in the vicinity of ∼160 K is evidence of a further glassy freezing process. This coincides with an acoustic loss peak and slight elastic stiffening that is typical of the outcome of freezing of ferroelastic twin walls. The results suggest that local strain variations associated with the ferroelastic twin walls couple with local moments to induce glassy magnetic behaviour.

show abstract

Section: Resultsmentioning

confidence: 99%

Coupling between phase transitions and glassy magnetic behaviour in Heusler alloy Ni₅₀Mn₃₄In₈Ga₈

Zhang

Lou

Zhou

et al. 2020

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…In another type of symmetry analysis related to incommensurate structures, Carpenter and Howard modelled the coupling between different types (concretely: first‐order (structural) and second‐order (shear‐strain)) of order parameters whose coupling has led to martensitic transition sequences in Heusler alloys. Despite the fact that they have perfectly applied the group–subgroup technique frequently used in the descriptions of structural phase transitions in modulated crystal structures, the use of line group theoretical methods is absent in this study, too.…”

Section: A Note On Possible Future Experimental Applicationsmentioning

confidence: 99%

Symmetry Analysis of Some Basic Structural Properties of Incommensurately Modulated Crystals by Projective Representations of Unimodular Groups

Mészáros

Nikolényi

Bálint

2019

Physica Status Solidi (b)

View full text Add to dashboard Cite

Projective representations of the unimodular groups are applied in the general symmetry theory of incommensurately modulated crystals. It is demonstrated that the algebraic condition relevant for the existence of line groups can be directly connected to those related to linear projective groups. As a concrete application example, the formalisms of the thermodynamic modelling of the structural phase transitions and the Fourier‐analysis formulae of the scattering processes in kinematic approximation are discussed by use of this group‐theoretical technique, introduced newly in this study for symmetry analyses of the general structural features of incommensurate systems.

show abstract

“…Lastly, the Heusler compounds were taken into consideration due to their various properties including the half-metals [1,2], spin-gapless half-metals, spin-gapless semiconductors [3,4] and topology insulators [5,6]. These compounds have several crystal structures such as full-Heusler (X 2 YZ) [7,8], half-Heusler (XYZ) [9,10], DO3 [11,12] and tetragonal [13,14] which all of these structures have the same crystallography structures.…”

Section: Introductionmentioning

confidence: 99%

Archives of Metallurgy and Materials

Parsamehr

Boochani

Sartipi

et al. 2020

View full text Add to dashboard Cite

The half-metallic, mechanical, and transport properties of the quaternary Heusler compound of PdZrTiAl is discussed under hydrostatic pressures in the range of -11.4 GPa to 18.4 GPa in the framework of the density functional theory (DFT) and Boltzmann quasi-classical theory using the generalization gradient approximation (GGA). By applying the stress, the band gap in the minor spin increases so that the lowest band is obtained 0.25 eV at the pressure of -11.4 GPa while the maximum gap is calculated 0.9 eV at the pressure of 18.4 GPa. In all positive and negative pressures, the PdZrTiAl composition exhibits a half-metallic behavior 100% spin polarization at the Fermi level. It is also found that applying stress increases the Seebeck coefficient in both spin directions. In the minority spin, the n-type PdZrTiAl, the power factor (PF) for all the cases is greater in the equilibrium state than the strain and stress conditions whereas in the majority spin, the PF value of the stress state is greater than the other two. The non-dimensional figure of merit (ZT) is significant and is about one in spin down in the room temperature for the all pressure states that it remains on this value by applying pressure. The obtained elastic constants indicate that the PdZrTiAl crystalline structure has a mechanical stability. Based on the Yong (E), Bulk (B) and shear (G) modulus and Poisson (n) ratio, the brittle-ductile behavior of this compound has been investigated under pressure. The results indicate that PdZrTiAl has a ductile nature and it is a stiffness compound in which elastic and mechanical instability increases by applying strain.

show abstract

Fundamental aspects of symmetry and order parameter coupling for martensitic transition sequences in Heusler alloys

Abstract: The combinations of phase transitions which occur in Heusler alloys in terms of order parameters and symmetry have been analysed using a group theoretical approach. It is shown how this approach can be applied to relevant examples.

Cited by 16 publications

References 60 publications

Coupling between phase transitions and glassy magnetic behaviour in Heusler alloy Ni₅₀Mn₃₄In₈Ga₈

Coupling between phase transitions and glassy magnetic behaviour in Heusler alloy Ni₅₀Mn₃₄In₈Ga₈

Symmetry Analysis of Some Basic Structural Properties of Incommensurately Modulated Crystals by Projective Representations of Unimodular Groups

Archives of Metallurgy and Materials

Contact Info

Product

Resources

About

Fundamental aspects of symmetry and order parameter coupling for martensitic transition sequences in Heusler alloys

Abstract: The combinations of phase transitions which occur in Heusler alloys in terms of order parameters and symmetry have been analysed using a group theoretical approach. It is shown how this approach can be applied to relevant examples.

Cited by 16 publications

References 60 publications

Coupling between phase transitions and glassy magnetic behaviour in Heusler alloy Ni50Mn34In8Ga8

Coupling between phase transitions and glassy magnetic behaviour in Heusler alloy Ni50Mn34In8Ga8

Symmetry Analysis of Some Basic Structural Properties of Incommensurately Modulated Crystals by Projective Representations of Unimodular Groups

Archives of Metallurgy and Materials

Contact Info

Product

Resources

About

Coupling between phase transitions and glassy magnetic behaviour in Heusler alloy Ni₅₀Mn₃₄In₈Ga₈

Coupling between phase transitions and glassy magnetic behaviour in Heusler alloy Ni₅₀Mn₃₄In₈Ga₈