A phase-field model of phase transitions and domain structures of NiCoMnIn metamagnetic alloys

Huang, Houbing; Ma, Xingqiao; Wang, J.J.; Liu, Z.H.; He, Wangqiang; Chen, Lei

doi:10.1016/j.actamat.2014.10.014

Cited by 31 publications

(12 citation statements)

References 40 publications

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“…The TDGL equation was solved by a semi‐implicit Fourier spectral method using a discreet grid of Δ x = 1 nm (Δ x is the size of grid points) with a given polarization boundary condition . An electric field of 5 MV·m −1 is applied along the z ‐axis.…”

Section: Theoretical Methodsmentioning

confidence: 99%

Size effects of electrocaloric cooling in ferroelectric nanowires

Huang

Zhang

et al. 2017

J Am Ceram Soc

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Considering finite size effect, ferroelectric nanowires may show novel phenomena compared to ferroelectric thin film and bulk. Here we investigated the effect of width and surface compressive stress on electrocaloric cooling in ferroelectric nanowire by using thermodynamic calculations and phase-field simulations. It was found that the isothermal entropy change and adiabatic temperature change in nanowire are 50% larger than that in thin film due to different mechanical boundary conditions of nanowire and thin film. The largest electrocaloric temperature changes were shown to increase significantly either with the decrease in nanowire width or the increase with the surface compressive stress. It was also revealed that the largest intrinsic entropy changes are almost the same for different nanowires with different widths and various stresses. The present study therefore contributes to the understanding of size effects of electrocaloric cooling and provides guidance for experiments to design high-efficiency cooling devices using ferroelectric nanosystems. K E Y W O R D S electrocaloric effect, ferroelectric nanowire, nanosize effects, phase-field simulation, thermodynamic calculation

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Section: Theoretical Methodsmentioning

confidence: 99%

Size effects of electrocaloric cooling in ferroelectric nanowires

Huang

Zhang

et al. 2017

J Am Ceram Soc

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“…Ferromagnetic shape memory alloys (FSMAs) such as NiMnGa [1,2], NiFeGa [3,4], NiMnInCo [5,6] have shown great potentials in a variety of applications as actuators, sensors, electromagnetic devices due to the shape memory effect (SME) and superelasticity (SE) under external fields, such as magnetic or stress fields [7,8]. It is well known that both SME and SE are associated with the stress-induced martensitic transformation (SIMT).…”

Section: Introductionmentioning

confidence: 99%

In-situ TOF neutron diffraction studies of cyclic softening in superelasticity of a NiFeGaCo shape memory alloy

Yang

Chen

et al. 2017

Materials Science and Engineering: A

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Real-time in-situ neutron diffraction was conducted during uniaxial cycling compression of a Ni 49.3 Fe 18 Ga 27 Co 5.7 shape memory alloy to explore the mechanism on its superelasticity at room temperature, which was manifested by the almost recoverable large strains and the apparent cyclic softening. Based on the Rietveld refinements, the real-time evolution of volume fraction of martensite was in-situ monitored, indicating the incremental amount of residual martensite with increasing load cycles. Real-time changes in intensities and lattice strains of {hkl} reflections for individual phase were obtained through fitting individual peaks, which reveal the quantitative information on phase transformation kinetics as a

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“…Premartensitic (PM) transformation, which is usually considered as the appearance of a precursor state, is a kind of weak first-order transition. The origin of modulation or shuffling is related to a TA 2 soft acoustic phonon mode of the austenitic phase at a wave vector q~1/3, which is corresponding to a minimum on the slowest transversal phonon branch and it is associated with nesting features of the Fermi surface [14,15]. Meanwhile, several kinds of abnormal properties on elasticity [16], thermology [17], electricity [18] and magnetism are found during phase transformation [19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

“…Meanwhile, several kinds of abnormal properties on elasticity [16], thermology [17], electricity [18] and magnetism are found during phase transformation [19][20][21][22]. The driving role of the electronic structure and its relationship with the lattice dynamics have been indicated by first-principle calculation [14] and experimental measurements on SMAs [23]. Various kinds of structural transformation characteristics have also been reported in Cu-Zn-Al [24], Ni-Ti [25,26], Ni-Fe-Ga [27], Eu 2 In [28] phase transition materials and novel high-carbon steels with cubic martensitic structures [29].…”

Section: Introductionmentioning

confidence: 99%

Superlattice in austenitic Ni-Mn-Ga shape memory microwires

Ding

et al. 2019

Journal of Alloys and Compounds

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The link between microstructure evolution, micromodulated domain and the structure transformation of Ni-Mn-Ga shape memory microwires prepared with rapid solidification is studied systematically by TEM and HRTEM. Multiple microdomain structures are determined according to the corresponding diffraction spots. The domain structure with a periodic distortion is a kind of characteristic of premartensitic phase. When cooling below the martensitic transformation temperature, the austenitic phase transforms to modulated 5M martensite, and the sequence of phase transformation can finally be confirmed from austenite to premartensite to 5M martensite during cooling. The characterization of micromodulated domain and the structure characteristics of austenite at atomic scale provide comprehensive understanding on the martensitic phase transformation route.

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A phase-field model of phase transitions and domain structures of NiCoMnIn metamagnetic alloys

Cited by 31 publications

References 40 publications

Size effects of electrocaloric cooling in ferroelectric nanowires

Size effects of electrocaloric cooling in ferroelectric nanowires

In-situ TOF neutron diffraction studies of cyclic softening in superelasticity of a NiFeGaCo shape memory alloy

Superlattice in austenitic Ni-Mn-Ga shape memory microwires

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