Possible Species of “Ferroelastic” Crystals and of Simultaneously Ferroelectric and Ferroelastic Crystals

Aizu, Kêitsirô

doi:10.1143/jpsj.27.387

Cited by 843 publications

(519 citation statements)

References 10 publications

Supporting

Mentioning

479

Contrasting

Unclassified

Order By: Relevance

“…However, in accordance with the symmetry theories of phase transformations [16][17][18][19], besides the transition Fm3m ! P 4=mmm, the structural transitions Fm3m !…”

Section: Introductionsupporting

confidence: 64%

“…L1 0 [22][23][24]. In accordance with current concepts on martensitic [25][26][27] and, in particular, ferroelastic [16,19,[28][29][30] phase transitions, these distinctive features can be considered as the main signs of the formation of a ferroelastic tetragonal disordered phase upon the displacive (martensitic) phase transformation Fm3m ! I4=mmm (A1 !…”

Section: Introductionsupporting

confidence: 55%

See 1 more Smart Citation

Discovery of metastable tetragonal disordered phase upon phase transitions in the equiatomic nanostructured FePd alloy

et al. 2013

View full text Add to dashboard Cite

Specific features of the phase transformation A1 ! L1 0 (space groups Fm3m and P4/mmm, respectively) in single crystals of the equiatomic alloy FePd subjected to annealings both in the absence and in the presence of external uniaxial load, as well as in polycrystalline samples that had undergone severe plastic deformation via high-pressure torsion and subsequent annealing, have been studied. An investigation of the single crystals in a nanostructured state formed at different stages of ordering annealing was performed using optical polarization, thermomagnetic and transmission electron microscopy (TEM) methods. The nanostructured state of the polycrystalline samples FePd after deformation of both disordered and ordered FePd alloys and subsequent annealing was examined with the help of TEM and X-ray techniques. The results obtained were analyzed based on the known concepts of the symmetry theory of phase transitions. It was concluded that the atomic ordering in the FePd alloys is preceded by the formation of a ferroelastic disordered bodycentered tetragonal phase with the structural type A6 and the space group I4/mmm. Experimental data that evidence the existence of a tetragonal disordered phase both in the single crystals and in the polycrystalline samples of FePd after severe plastic deformation and subsequent annealing are reported. Thus, the A1 M A6 M L1 0 phase transformation represents a combination of different types of phase transitions such as cooperative displacement A1 M A6 and ordering A6 M L1 0 of atoms.

show abstract

“…However, in accordance with the symmetry theories of phase transformations [16][17][18][19], besides the transition Fm3m ! P 4=mmm, the structural transitions Fm3m !…”

Section: Introductionsupporting

confidence: 64%

Section: Introductionsupporting

confidence: 55%

Discovery of metastable tetragonal disordered phase upon phase transitions in the equiatomic nanostructured FePd alloy

et al. 2013

View full text Add to dashboard Cite

show abstract

“…At 481 K SOI undergoes a displacive phase transition in the course of which the symmetry is reduced to C Szh (P 21/c ) of the monoclinic system. Thus, according to the nomenclature of Aizu [1], SOI belongs to the full ferroelastic species 6/mF2/m having three orientational states of different spontaneous strain. The prototypic point group C6h may be decomposed into the direct product C3XC2h where C2h is the point group of the ferroic phase.…”

Section: Crystal Structurementioning

confidence: 99%

“…Aizu has shown that a distinct class of crystals determined by symmetry may properly be called ferroelastics [1]. Ferroelasticity is most easily defined by its close analogy to ferroelectricity, where one has to replace the polarization by the strain and the electric field by the mechanical stress.…”

Section: Introductionmentioning

confidence: 99%

“…By a suitably chosen external stress the strain orientation may be shifted from one state to another. By symmetry considerations Aizu found that among the nonmagnetic space groups there are 94 possible species of ferroelastic crystals and among these 52 are pure ferroelastic whereas the remaining 42 species are simultaneously ferroelastic and ferroelectric [1]. Up to now only few crystals are proved to be pure ferroelastic.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Raman scattering investigation of ferroelastic Sb5O7I crystals

1975

View full text Add to dashboard Cite

Abstract. Sb5071 undergoes a displacive phase transition at 481 K where the symmetry is changed from CZ6h to C~h. In the low temperature monoclinic phase the crystal is ferroelastic. The polarized Raman spectra of SbsOTI ha9e been measured at various temperatures below and above the phase transition. The frequencies and symmetries of most of the theoretically expected Raman active phonons in the ferroelastic phase have been determined. The observation of a soft mode in the ferroelastic phase which disappears above the phase transition together with the fact that the unit cell of the ferroelastic phase is twice as large as that of the paraelastic structure permits the conclusion that the phase transition results from a phonon instability at the Brillouin zone boundary M-point of the hexagonal phase, The temperature dependent splittings and intensity changes of several Raman lines are discussed with respect to the ferroelastic property of the crystal and the phase transition.

show abstract

The Studies of Ferroelastic Phase Transitions and Domain Walls in KMgCl3 Crystal

Jeong

Cho

Ahn

et al. 1998

Cryst. Res. Technol.

View full text Add to dashboard Cite

Possible Species of “Ferroelastic” Crystals and of Simultaneously Ferroelectric and Ferroelastic Crystals

Cited by 843 publications

References 10 publications

Discovery of metastable tetragonal disordered phase upon phase transitions in the equiatomic nanostructured FePd alloy

Discovery of metastable tetragonal disordered phase upon phase transitions in the equiatomic nanostructured FePd alloy

Raman scattering investigation of ferroelastic Sb5O7I crystals

The Studies of Ferroelastic Phase Transitions and Domain Walls in KMgCl3 Crystal

Contact Info

Product

Resources

About