Misfit strain–film thickness phase diagrams and related electromechanical properties of epitaxial ultra-thin lead zirconate titanate films

Qiu, Q. Y.; Mahjoub, Reza; Alpay, S. P.; Valanoor, Nagarajan

doi:10.1016/j.actamat.2009.09.060

Cited by 34 publications

(14 citation statements)

References 72 publications

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“…Therefore, some modifications should be made to the coefficients of Eqs. (2) as follows 28,29 : For x 1 direction:…”

Section: Phase Field Methods Of Ferroelectric Thin Filmsmentioning

confidence: 99%

Domain structures of ferroelectric films under different electrical boundary conditions

Zhou

2015

AIP Advances

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A two-dimensional phase field simulation of ferroelectric films is used that incorporates Landau-Devonshire energy, gradient energy and depolarization electrical energy. A new intermediate electrical boundary condition is firstly presented to study the effects on domain structures of ferroelectric films. Two-dimensional simulations of domain structures are carried out under the open circuit (OC), short circuit (SC) and intermediate (IM) electrical boundary conditions. The simulation results show that there are multi-vortices domains and 180° multi-stripes domains under OC and SC electrical boundary condition, respectively. And there is a transition from multi-vortices domains to 180° multi-stripes domains under the IM electrical boundary condition due to competition between the elastic energy and depolarization electrical energy in the films. The present IM electrical boundary condition can completely characterize different degrees of compensation for surface charges by the electrodes and further describe the effect on the depolarization electrical energy. It can also be reduced to OC and SC electrical boundary conditions. Hence, for nano-thin ferroelectric films, the IM electrical boundary condition plays an important role in the formation of domain structures.

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“…Therefore, some modifications should be made to the coefficients of Eqs. (2) as follows 28,29 : For x 1 direction:…”

Section: Phase Field Methods Of Ferroelectric Thin Filmsmentioning

confidence: 99%

Domain structures of ferroelectric films under different electrical boundary conditions

Zhou

2015

AIP Advances

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“…7. In our calculations, we have used the same parameters as Qiu et al 45 . The LGD results are in agreement with our first-principles calculations, reproducing a F E x ground state under compressive stress and a F E z groundstate under tensile stress.…”

Section: Uniaxial Stressmentioning

confidence: 99%

First-principles study ofPbTiO3under uniaxial strains and stresses

2014

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The behavior of PbTiO3 under uniaxial strains and stresses is investigated from first-principles calculations within density functional theory. We show that irrespectively of the uniaxial mechanical constraint applied, the system keeps a purely ferroelectric ground-state, with the polarization aligned either along the constraint direction (F Ez phase) or along one of the pseudo-cubic axis perpendicular to it (F Ex phase). This contrasts with the cases of isotropic or biaxial mechanical constraints for which novel phases combining ferroelectic and antiferrodistortive motions have been previously reported. Under uniaxial strain, PbTiO3 switched from a F Ex ground state under compressive strain to F Ez ground-state under tensile strain, beyond a critical strain η c zz ≈ +1%. Under uniaxial stress, PbTiO3 exhibits either a F Ex ground state under compression (σzz < 0) or a F Ez ground state under tension (σzz > 0). Here, however, an abrupt jump of the structural parameters is also predicted under both compressive and tensile stresses at critical values σzz ≈ +2 GPa and −8 GPa. This behavior appears similar to that predicted under negative isotropic pressure and might reveal practically useful to enhance the piezoelectric response in nanodevices.

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“…In addition, at 150-nm thickness, there was a compressive strain relaxation caused by the formation of dislocation, resulting in the increase of a-domains in the thin film [38]. Moreover, Qiu et al [41,42] carried out studies on possible relaxation mechanisms as a function of film thickness in PTO and PZT thin films. Thus, the simulation result obtained for a thin film subjected to a tensile epitaxial strain, e epi = 0.4 %, is chosen to compare with the corresponding result from Ref.…”

Section: Domain-switching Dynamicsmentioning

confidence: 97%

Phase-field modeling of the influence of domain structures on the electrocaloric effects in PbTiO3 thin films

et al. 2014

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A phase-field model has been developed to study the influence of epitaxial strains and domain structures on the electrocaloric effects (ECEs) in PbTiO 3 (PTO) thin films. The simulated domain-switching dynamics obtained from the proposed model was tallied with the existing experimental results. In the case of single-domain PTO thin film, the ECE gradually increased with the increasing epitaxial strain, whereas, in the case of polydomain PTO thin film, the influence of epitaxial strain on ECE can be divided into three regions of stable domain structures, i.e., c-domains, a/c-domains, and a-domains regions. It is worth noting that the maximum ECE occurred under a tensile epitaxial strain in the a/c-domains region, which was the consequence of the competition between the enhancement of ECE and the reduction of c-domains volume fraction, both caused by the increasing tensile epitaxial strain. Although the change of temperature arising from the ECE may not be large enough to be viable for practical applications, it does illustrate the important influence of domain structures on the ECEs of thin films, which has not gained much attention of most researchers whose focus is still on single-domain thin films.

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Misfit strain–film thickness phase diagrams and related electromechanical properties of epitaxial ultra-thin lead zirconate titanate films

Cited by 34 publications

References 72 publications

Domain structures of ferroelectric films under different electrical boundary conditions

Domain structures of ferroelectric films under different electrical boundary conditions

First-principles study ofPbTiO3under uniaxial strains and stresses

Phase-field modeling of the influence of domain structures on the electrocaloric effects in PbTiO3 thin films

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