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Rapid and robust spatiotemporal dynamics of the first-order phase transition in crystals of the organic-inorganic perovskite (C12H25NH3)2PbI4.

Yangui A, Sy M, Li L, Abid Y, Naumov P, Boukheddaden K - Sci Rep (2015)

Bottom Line: The thermal hysteresis loop is 10 K wide, and the interface velocity is constant at V ≈ 1.6 mm s(-1).The progression of the habit plane is at least 160 times faster than in spin-crossover materials, and opens new prospects for organic-inorganic perovskites as solid switching materials.These hitherto unrecognized properties turn this and possibly similar hybrid perovskites into perspective candidates as active medium for microscopic actuation.

View Article: PubMed Central - PubMed

Affiliation: Groupe d'Etudes de la Matière Condensée, Université de Versailles, CNRS UMR 8635, 45 Avenue des Etats Unis, 78035 Versailles, France.

ABSTRACT
The dynamics of the thermally induced first-order structural phase transition in a high-quality single crystal of the organic-inorganic perovskite (C12H25NH3)2PbI4 was investigated by optical microscopy. The propagation of the straight phase front (habit plane) during the phase transition along the cooling and heating pathways of the thermal hysteresis was observed. The thermochromic character of the transition allowed monitoring of the thermal dependence of average optical density and aided the visualization of the interface propagation. The thermal hysteresis loop is 10 K wide, and the interface velocity is constant at V ≈ 1.6 mm s(-1). The transition is accompanied with sizeable change in crystal size, with elongation of ~6% along the b axis and compression of ~ -2% along the a axis, in excellent agreement with previously reported X-ray diffraction data. The progression of the habit plane is at least 160 times faster than in spin-crossover materials, and opens new prospects for organic-inorganic perovskites as solid switching materials. Moreover, the crystals of (C12H25NH3)2PbI4 are unusually mechanically robust and present excellent resilience to thermal cycling. These hitherto unrecognized properties turn this and possibly similar hybrid perovskites into perspective candidates as active medium for microscopic actuation.

No MeSH data available.


Related in: MedlinePlus

Local kinetics of the nucleation regime ahead the interface.Time-dependence of the normalized local optical density (OD) upon heating along a line perpendicular to the front propagation direction. The red curve is the best fit obtained using equation 2.
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f5: Local kinetics of the nucleation regime ahead the interface.Time-dependence of the normalized local optical density (OD) upon heating along a line perpendicular to the front propagation direction. The red curve is the best fit obtained using equation 2.

Mentions: To address the problem of local kinetics of the transformation process, the change of OD along the a axis with time was extracted during the front propagation, that is, perpendicular to the front propagation direction. The plot of the OD as a function of time provided a set of kinetic curves whose average (Fig. 5) can be described in terms of a nucleation-and-growth process, following the well-known KJMA-type law28:


Rapid and robust spatiotemporal dynamics of the first-order phase transition in crystals of the organic-inorganic perovskite (C12H25NH3)2PbI4.

Yangui A, Sy M, Li L, Abid Y, Naumov P, Boukheddaden K - Sci Rep (2015)

Local kinetics of the nucleation regime ahead the interface.Time-dependence of the normalized local optical density (OD) upon heating along a line perpendicular to the front propagation direction. The red curve is the best fit obtained using equation 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644986&req=5

f5: Local kinetics of the nucleation regime ahead the interface.Time-dependence of the normalized local optical density (OD) upon heating along a line perpendicular to the front propagation direction. The red curve is the best fit obtained using equation 2.
Mentions: To address the problem of local kinetics of the transformation process, the change of OD along the a axis with time was extracted during the front propagation, that is, perpendicular to the front propagation direction. The plot of the OD as a function of time provided a set of kinetic curves whose average (Fig. 5) can be described in terms of a nucleation-and-growth process, following the well-known KJMA-type law28:

Bottom Line: The thermal hysteresis loop is 10 K wide, and the interface velocity is constant at V ≈ 1.6 mm s(-1).The progression of the habit plane is at least 160 times faster than in spin-crossover materials, and opens new prospects for organic-inorganic perovskites as solid switching materials.These hitherto unrecognized properties turn this and possibly similar hybrid perovskites into perspective candidates as active medium for microscopic actuation.

View Article: PubMed Central - PubMed

Affiliation: Groupe d'Etudes de la Matière Condensée, Université de Versailles, CNRS UMR 8635, 45 Avenue des Etats Unis, 78035 Versailles, France.

ABSTRACT
The dynamics of the thermally induced first-order structural phase transition in a high-quality single crystal of the organic-inorganic perovskite (C12H25NH3)2PbI4 was investigated by optical microscopy. The propagation of the straight phase front (habit plane) during the phase transition along the cooling and heating pathways of the thermal hysteresis was observed. The thermochromic character of the transition allowed monitoring of the thermal dependence of average optical density and aided the visualization of the interface propagation. The thermal hysteresis loop is 10 K wide, and the interface velocity is constant at V ≈ 1.6 mm s(-1). The transition is accompanied with sizeable change in crystal size, with elongation of ~6% along the b axis and compression of ~ -2% along the a axis, in excellent agreement with previously reported X-ray diffraction data. The progression of the habit plane is at least 160 times faster than in spin-crossover materials, and opens new prospects for organic-inorganic perovskites as solid switching materials. Moreover, the crystals of (C12H25NH3)2PbI4 are unusually mechanically robust and present excellent resilience to thermal cycling. These hitherto unrecognized properties turn this and possibly similar hybrid perovskites into perspective candidates as active medium for microscopic actuation.

No MeSH data available.


Related in: MedlinePlus