Analysis of the Polarization Distribution in a Polar Perhydrotriphenylene Inclusion Compound by Scanning Pyroelectric Microscopy

Quintel, Andrea; Hulliger, Jürg; Wübbenhorst, Michael

doi:10.1021/jp973350p

Cited by 75 publications

(54 citation statements)

References 12 publications

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“…12 The Pyroelectric Scanning Microscopy (PSM) records the two-dimensional distribution of pyroelectric response by scanning a focused and modulated laser beam across a pyroelectric sample and recording the induced surface charge. 13,14 PSM works with crystals [13][14][15][16][17][18][19] and with thin films. [20][21][22][23] PSM has also been used to image domains 14,24 thermally written polarization patterns, [25][26][27][28] and to follow polarization and domain dynamics.…”

mentioning

confidence: 99%

Polarization imaging in ferroelectric polymer thin film capacitors by pyroelectric scanning microscopy

Song

Gruverman

et al. 2014

Applied Physics Letters

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mentioning

confidence: 99%

Polarization imaging in ferroelectric polymer thin film capacitors by pyroelectric scanning microscopy

Song

Gruverman

et al. 2014

Applied Physics Letters

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“…Scanning Pyroelectric Microscopy (SPEM) [29][30][31] Scanning a presumably bi-polar crystal placed into a capacitor by an intensity modulated laser beam effecting spot-wise heating, will, depending on the local extent of polarity, show a displacement current (being detected by a lock-in technique). Mapping the current originating from a thin heat absorbing surface layer allows one to reconstruct a 2D representation of the pyroelectric strength of a material.…”

Section: Wwwcrt-journalorgmentioning

confidence: 99%

Dissymetrization of molecular crystals: a driving force for property formation

Hulliger¹,

Batagiannis

2008

Cryst. Res. Technol.

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Phenomena of dissymetrization of molecular crystals are reviewed which lead to sector wise polar properties. Orientational disorder of prolate-type dipolar molecules taking place at attachment sites can produce partial polar alignment of dipoles in corresponding growth sectors of molecular crystals nucleating into topologically centric packings. As a result bi-polar crystals are obtained. In case of native polar groups, Monte Carlo simulations predict a basic behaviour for pyroelectric molecular crystals: the dipoles belonging to sectors of either the plus or minus direction of the unique axis show a non-vanishing probability to be gradually reversed. Domain reversal may start upon a single orientational defect developing into complete sector reversal. Basic features of growth induced stochastic polarity formation are confirmed by scanning pyroelectric microscopy, phase sensitive second harmonic generation microscopy and x-ray scattering. Real systems comprise channel-type inclusion compounds, single component molecular crystals, solid solutions and long chain proteins in natural tissues. Neumann's principle gives thought to physical properties of bulk crystals [2], although building blocks undergo attachment to surfaces confined to 2D point groups. For growth induced properties, Neumann's principle may thus be restated as follows [3]: The symmetry elements of a physical property of a growth sector include all symmetry elements of the point group of the growth sector. Properties resulting explicitly from processes at the crystal-nutrient interface are those, which in principle should disappear if thermalization of the bulk structure far off the surface has reached the minimum of free energy. Growth processes leading to the dissymmetrization of crystals are known for a long time [4][5][6] and were mainly discussed for minerals [7]. For a review discussing also molecular crystals featuring optical anomalies [8]. Recently, we have reviewed the impact of surface symmetry on growth-induced properties emerging from corresponding families of faces of the 32 point groups. Explicitly, a symmetry analysis for a vector property, i.e. pyroelectricity was performed [3].Here, we shall understand dissymetrization as a constructive phenomenon for physical property formation. Vector property formation is particularly interesting in the case of molecular crystals, constituted by prolate shaped dipolar molecules. After an extensive experimental [9][10][11][12] and theoretical [3,[13][14][15][16][17][18][19][20][21][22][23] analysis starting in 1995, we are about to conclude that any dipolar molecule crystallizing into a crystal structure described on average by a non-polar point group undergoes (to some extent) sector-wise dissymetrization, leading to sectors showing polar properties. Growth-induced polarity formation leads to non-classical twinning, i.e. bi-polar states of molecular crystals.The basic phenomenon behind growth induced polarity formation is symmetry breaking at the crystalnutrient interface. The probabilities of att...

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“…The needle axis corresponds to the channel axis. Further details concerning the crystal growth and the sample preparation are described in [7].…”

Section: Preparation Of Phtp Inclusion Compoundsmentioning

confidence: 99%

“…A first important result from SPEM imaging on PHTP-NPP inclusion crystals was the observation of macrodomains featuring opposite polarizations [7,12]. Recent SPEM experiments of the crystal core region, utilizing an improved spatial resolution (-10 pm), showed an hourglass shaped domain structure, which was predicted by a growth model based on Markov's theory of stochastic processes.…”

Section: -Iodo-4-nitrobiphenyl (Inbp) )mentioning

confidence: 99%

Spontaneous polarization and orientational dynamics of polar rod-like molecules in host/guest materials

Wubbenhorst¹,

Turnhout²,

Klap³

et al. 2000

IEEE Trans. Dielect. Electr. Insul.

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The polar domain structure and dynamics of hostlguest materials which include polar rodlike molecules were investigated by pyroelectric and dielectric techniques. Using scanning pyroelectric microscopy (SPEM), spatially resolved information on a p m scale was obtained of the 3-D domain structure of the polarization caused by an acentric host lattice andlor the polar arrangement of dipolar guest molecules. Two classes of pyroelectric host/guest materials were examined with SPEM: (1) an inorganic host (zeolite AIP04-5) which was loaded with pnitroaniline (PNA) guest molecules by an adsorption process, and (2) an organic channel-type inclusion material, which establishes its macroscopic polarity by cocrystallization of perhydrotriphenylene (PHTP) with the polar guest 1-(4-nitrophenyl)piperazine) ("9. Despite great differences in the chemical composition and morphology, both types of hostlguest systems revealed 180" macro-domains, of which the particular shape and sign of the polarization were in accordance with models about crystal growth andlor directed adsorption of polar molecules. In order to assess the molecular dynamics of the included guest molecules, frequency dependent local pyroelectric measurement, based on SPEM, and broad-band dielectric relaxation spectroscopy were performed. Whereas guest molecules included in PHTP channels show no rotational dynamics, we found several relaxation processes in PNA-loaded AlP04-5 crystals, which were assigned to local and cooperative relaxation modes of molecular chains of the hydrogen-bonded PNA guest molecules.

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Analysis of the Polarization Distribution in a Polar Perhydrotriphenylene Inclusion Compound by Scanning Pyroelectric Microscopy

Cited by 75 publications

References 12 publications

Polarization imaging in ferroelectric polymer thin film capacitors by pyroelectric scanning microscopy

Polarization imaging in ferroelectric polymer thin film capacitors by pyroelectric scanning microscopy

Dissymetrization of molecular crystals: a driving force for property formation

Spontaneous polarization and orientational dynamics of polar rod-like molecules in host/guest materials

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