Conduction plane frequency-dependent

Relative to microelectronic applications, the out-of-plane dielectric constant for BPDA-PFMB films measmed after aging at 50% relative humidity for 48 h at 23°C was between 2.8 and 2.9 (0.1 kHz to 1 MHz) (ASTM D-150-81These values are considerably lower than that of commercial polyimides such as PMDA-ODA (pyromellitic dianhydride, PMDA) (s = 3.5 at 1 kHz and 3.3 at 10 MHz). The dielectric constant and tan 8 (dissipation factor) were temperature- and frequency-dependent. The dielectric constant, which was independent of temperature until near 210°C increased above this point until a frequency-dependent maximum was reached at about 290°C. The dissipation factor, which was also independent of temperatme below 200°C, underwent a rapid increase with no maximum between 200 and 400°C owing to ion conductivity. The temperatme at which this increase occurred increased as the frequency increased. The films also... 

Figure 4.9 Dog excised skeletal muscle (37 °C) frequency dependence and anisotropy. Current path J transversal, II longitudinal to muscle fibers, (a) Complex resistivity in the Wessel plane, (b) relative permittivity, and (c) conductivity. Redrawn from Epstein Foster (1983), by permission.

Fig. 7. Optical constants (in-plane) for a series of underdoped high-7J superconductors. Top row real part of the optical conductivity. Middle row frequency dependent scattering rate. Bottom row mass renormalization. Experimental data for Y123 and Y124 compounds from Basov et al. (1996) for Bi2212 compounds from Puchkov et al. (1996b). The scattering rate curves are essentially temperature independent above 1000 cm" but develop a depression at low temperature and at low frequency. The effective mass is enhanced at low temperature and at low frequency. Experimental results in the normal state at T s and in the superconducting state ate...

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