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Showing 1 to 13 of 13 for “"paraelectric"”.
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Impact of the interface on the paraelectric to ferroelectric phase transition in expitaxial BaSrTiO 3 thin film capacitors
The ever increasing memory densities of the so called Dynamic Random Access Memory (DRAM) lead to a drastic reduction of the area of the incorporated storage capacitors. As a consequence, the film thickness of the used dielectrics has to be decreased in a similar way. When considering …
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Competition and Coexistence of Screening Mechanisms in Ferroelectric Thin Films and Superlattices
… superlattices of alternating ferroelectric and paraelectric layers was also obtained. In both cases a modified Kittel law was observed for the domains which accounts for the substrates and the superlattice geometries. We review the model of coexistence between screening mechanisms for a …
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The attenuation of flow-induced tonal noise using plasma actuators
… of 3.6 x 104 to 7.1 x 104.<br/>An array of paraelectric plasma actuators were located on the approaching surface to the cavity, aligned with the direction of the oncoming flow. Results show that the paraelectric plasma actuators can produce a significant attenuation of the dominant cavity …
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Untersuchung der strukturellen Phasenübergänge und Domänenbildung in den ferroischen Modellsubstanzen RbH 2 PO 4 und RbD 2 PO 4
… number of works concerning the ferroelectric - paraelectric phase transition of KDP investigated by a great variety of methods have been published. But the principal mechanism of the phase transition is still not understood. One of the basic problems here is the so called isotope effect. Just by …
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Transformation induced plasticity in ceramics
… the martensitic transformation from the cubic (paraelectric) to the tetragonal ( ferroelectric) phase in BaTiO3 was determined. The K1C fracture toughness, as measured by the hardness indentation technique, exhibits a maximum within a temperature range approximately 50°C above the stress-free …
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Dynamics of lattice vibrations, molecular rotations and spins studied by terahertz spectroscopy
… between the spins. In a bulk quantum paraelectric material, we have observed temperature-dependent lattice dynamics and fluctuating polar domain dynamics, both associated with the incipient ferroelectric structural phase transition, through time-resolved optical second harmonic …
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High-strain actuation of lead-free perovskites : compositional effects, phenomenology and mechanism
… antiferroelectric, ferroelastic and paraelectric behavior has been developed. Major electromechanical properties of polycrystalline BNBZT have been identified and compositionally mapped. The peak of electromechanical response (d33 = 400 pC/N) has been found at the composition …
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Investigation of van der Waals ferroelectric CuInP2S6 by scanning probe microscopy
… which exhibits a nanoscale phase separation. The paraelectric In4/3P2S6 (IPS) phase exhibits higher friction than the ferroelectric CIPS phase, while phase boundaries display the lowest friction. We also observe a thickness-dependent friction behaviour in Cu0.2In1.26P2S6. The friction in this vdW …
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Large-Scale Atomistic Simulations of Complex and Functional Properties of Ferroic Materials
… via negative capacitance in ferroelectric-paraelectric superlattices. We employ HEff in Monte Carlo and molecular dynamics schemes to maximize spontaneous optical rotation in a BaTiO$_3$/SrTiO$_3$ nanocomposite. For a small bias field, maximal optical rotation was realized at room …
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Aging and Barkhausen noise in the relaxor ferroelectrics
… PMN/PT (90/10) of about 100 nanodomains in the paraelectric regime, which then abruptly freezes out on cooling into the relaxor regime. This suggests an abrupt growth of barriers associated with the dipoles. The presence of complicated spin-glass-like aging, requiring cooperativity between many …
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A Force Sensor Array for Space Applications
… published in literature. The permittivity of the paraelectric polymer matrix is modeled, accounting for piezodielectric effects imposed by external pressure and thermally induced stresses caused by substrate pinning. Similarly, the ferroelectric ceramic filler is modeled, considering changes in …
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Quantum Critical Ferroelectricity and Emergent Phenomena in KTaO3 and SrTiO3
… phase diagrams of KTaO3 and SrTiO3, both quantum paraelectrics near to a ferroelectric quantum critical point, including study of material properties which may be influenced by proximity to a ferroelectric quantum phase transition. A quantum critical phase transition is one where the system …
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Preparation and Characterization of Ferroelectric Thin Films for Tunable and Pyroelectric Applications
… phase transition between the ferroelectric and paraelectric states. The present study is expected to help better understand the potential of BTS thin films. The efforts toward improving the tunable and pyroelectric properties of BTS thin films have demonstrated the appealing prospective …