The Dielectric Response of Hydrated PFSA Membranes at Microwave Frequencies Using Split Post Dielectric Resonators

2011 ◽  
Keyword(s):  
Dielectric Response ◽  
Dielectric Resonators ◽  
Microwave Frequencies

Polarization Dynamics in La5/3Sr1/3NiO4

1999 ◽  
Vol 602 ◽  
Author(s):  
N. Hakim ◽  
Z. Zhai ◽  
C. Kusko ◽  
P.V. Parimi ◽  
S-W. Cheong ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Dielectric Response ◽  
Charge Ordering ◽  
Dielectric Susceptibility ◽  
Dynamic Susceptibility ◽  
Loss Peak ◽  
Relaxation Rates ◽  
Relaxation Mode ◽  
Microwave Frequencies ◽  
Charge Stripe

AbstractDynamic susceptibility measurements at microwave frequencies (2 – 10GHz) are a sensitive probe of charge dynamcis in La5/3Sr1/3NiO4. Below the charge ordering temperature of 240K, a dielectric loss peak due to a relaxation mode with a large dielectric susceptibility is observed, and is associated with charge stripe formation. The dielectric response for Hω∥b (Eω ⊥ b) is well represented by ε(T) = εo/(1 – iωτ(T)), with εo, ∼ 50, and τ(T) = 2 × 10−9(sec) exp(−T/37K). Parallel conductivity σ(T) contributions dominate at higher temperatures and for Hω∥c (Eω ⊥ c). The dielectric loss peak observed indicates that the charge relaxation rates lie in the GHz frequency ranges.

Microwave Responce from La- and Dy- doped BiFeO3 Thin Films

2006 ◽  
Vol 966 ◽  
Author(s):  
Peter Kr. Petrov ◽  
Vaijayanti R Palkar ◽  
Neil McN Alford ◽  
Alexander K Tagantsev ◽  
K Prashanthi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Dielectric Response ◽  
Domain Walls ◽  
Structural Features ◽  
Type I ◽  
Microwave Frequencies ◽  
Bifeo3 Thin Films ◽  
Electric And Magnetic Fields ◽  
Exact Origin

ABSTRACTThe dielectric response of La- and Dy- doped BiFeO3 thin films to electric- and magnetic fields was measured at microwave frequencies (up to 12GHz) in a temperature range from 25 °C to 300 °C. Interesting phenomena were observed. Significant oscillations in the C(f) characteristic which were unaffected by the electric field or by elevated temperature but which were dampened by a magnetic field. We also observed ‘N’-type I-V characteristics. A possible explanation for this mesoscopic response is the presence of structural features that cause resonance (e.g. grains, grain-boundaries, domains, domain walls etc), with a contribution strong enough to be averaged by the system. The exact origin of these features is unknown at present.

Effect of Divalent Dopants on Properties of Ba3.75Nd9.5Ti18O54 Microwave Dielectric Resonators

1996 ◽  
Vol 453 ◽  
Author(s):  
R. Ubic ◽  
I. M. Reaney ◽  
W. E. Lee ◽  
J. Samuels ◽  
E. Evangelinost
Keyword(s):  
Solid Solution ◽  
Dielectric Properties ◽  
Mixed Oxide ◽  
Theoretical Density ◽  
Dielectric Resonators ◽  
Ternary Solid Solution ◽  
Microwave Frequencies ◽  
Microwave Dielectric ◽  
Commercial Applications ◽  
Pb Substitution

AbstractPellets in the ternary solid-solution Ba6–3xNd8+2xTi18O54 (x=0.75) have been processed to near theoretical density by mixed-oxide synthesis, and their dielectric properties determined to be εr≈89, Qf> 10,000, and τf≈+60ppm/°C at microwave frequencies. Similar ceramics with Ca, Sr, and Pb partially substituted for Ba were also processed and analysed. Both Ca and Sr were found to increase εr to 100–105 but significantly lower Qf and inflate τf. While Pb substitution also lowered Qf, it had no significant effect on εr and beneficially suppressed τf to values from -16 to +8ppm/°C, tunable with Pb content, strongly suggesting that these materials may be useful for commercial applications.

scholarly journals Chiral All-Dielectric Metasurface Based on Elliptic Resonators with Circular Dichroism Behavior

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ali Yahyaoui ◽  
Hatem Rmili
Keyword(s):  
Circular Dichroism ◽  
Design Procedure ◽  
Design Parameters ◽  
Dielectric Resonators ◽  
Polarization Filter ◽  
Microwave Frequencies ◽  
Main Design ◽  
Circular Polarizer ◽  
Circular Dichroïsm ◽  
Dielectric Metasurface

We present the design of a new microwave all-dielectric chiral metasurface with circular dichroism behavior based on elliptic dielectric resonators (EDRs). During the design procedure, we have first optimized numerically the effects of the main design parameters such as the resonator’s size and orientation, as well as the size of the slot within them, on the metasurface transmission over the frequency band 10–20 GHz. Measurements on the final metasurface prototype have shown a large circular dichroism (Δ=0.61 and Δ=0.5) over two bands (17.55–17.61 GHz and 17.91–18.05 GHz) with ellipticities close to 45° which means that the developed device can be used as a circular polarization filter and circular polarizer at microwave frequencies.

scholarly journals Dielectric Resonators for the Measurements of the Surface Impedance of Superconducting Films

2014 ◽  
Vol 14 (3) ◽  
pp. 164-170 ◽  
Author(s):  
N. Pompeo ◽  
K. Torokhtii ◽  
E. Silva
Keyword(s):  
Thin Films ◽  
Magnetic Fields ◽  
Surface Impedance ◽  
Applied Field ◽  
Superconducting Films ◽  
Dielectric Resonators ◽  
Superconducting Thin Films ◽  
Microwave Frequencies ◽  
Sample Measurement

Abstract We present the development, realization and setup of dielectric resonators, for the purpose of measuring the surface impedance at microwave frequencies of superconducting thin films. We focus on resonators designed to operate in dc magnetic fields, optimized for the measurements of the variation of the surface impedance with the applied field. Two resonators, operating at 8 and 48 GHz, are presented. We discuss different approaches to the measurement of the resonator parameters, with particular attention to the nonidealities of real setups in a cryogenic environment. Finally, we present some sample measurement of high-Tc and low-Tc superconducting films.

Nonlocal dielectric response in dipolar polymers

1993 ◽  
Vol 3 (4) ◽  
pp. 503-513 ◽  
Author(s):  
M. Warner ◽  
M. E. Cates
Keyword(s):  
Dielectric Response
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