Pressure and Temperature Derivatives of the Low-Frequency Dielectric Constants of LiF, NaF, NaCl, NaBr, KCl, and KBr

“…Therefore, either a measurement with uniaxial stress and longitudinal electrodes or a measurement with hydrostatic stress is required t o get all of the independent tensor components. Because the hydrostatic stress derivatives of the dielectric constants of alkali halides are already known with sufficient precision [5], it is possible to use transverse electrodes only. Table 1 shows (1/T) (AClC) for the most important stressdirections and for hydrostatic stress.…”

Section: Sample Geometrymentioning

confidence: 99%

Uniaxial Stress Dependence of the Static Dielectric Constant of Some Alkali Halides

Barth¹,

Lorke²,

Mohler³

1985

Physica Status Solidi (b)

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A sensitive method to measure the strain derivatives of the static dielectric constant of uniaxially stressed crystals is described. With stress modulation and phase-sensitive detection, changes as small as 5 x of the sample's capacitance can be detected. The piezodielectric and electrostrictive tensor components of LiF, NaCl, and KC1 are given. The experimental results are compared with theoretical estimates of these coefficients based on lattice dynamical models.Es wird ein empfindliches Verfahren zur Messung von Anderungen der statischen Dielektrizitatskonstante elastisch deformierter Kristalle beschrieben. Mittels Druckmodulation und phasenempfindlicher Gleichrichtung konnen noch Anderungen von 5 x der Probenkapazitat nachgewiesen werden. Die piezodielektrischen Tensorkomponenten und die Elektrostriktionstensoren von LiF, NaCl und KCl werden bestimmt. Die experimentellen Resultate werden mit theoretischen Abschatzungen dieser Koeffizienten auf der Grundlage gitterdynamischer Modelle verglichen.

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“…7 , 8 In an attempt to further elucidate the role of water in the proton conductiv-iy mechanism of Nafion 117, electrical conductivity and NMR studies conductance divided by the angular frequency, G/om, were measured at various temperatures and pressures using techniques described elsewhere. 9 The pressure fluid was Fluorinert (FC-77) Electronic Liquid.…”

Section: Abstract (Maximum 200 Words)mentioning

confidence: 99%