High Frequency Measurements of Ferroelecrics and Related Materials in Coaxial Line

Banys, J.; Lapinskas, S.; Rudys, Saulius; Greicius, S.; Grigalaitis, R.

doi:10.1080/00150193.2011.577308

Cited by 23 publications

(12 citation statements)

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“…(iii) 1 MHz-1 GHz band: the complex reflection coefficient was measured with Agilent 8714ET vector network analyzer. The multimode capacitor model was used to calculate the real and imaginary parts of complex dielectric permittivity 66 . (iv) 26-50 GHz band: the scalar transmission and reflection coefficients were measured in a waveguide system.…”

Section: Methodsmentioning

confidence: 99%

Suppression of phase transitions and glass phase signatures in mixed cation halide perovskites

et al. 2020

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Cation engineering provides a route to control the structure and properties of hybrid halide perovskites, which has resulted in the highest performance solar cells based on mixtures of Cs, methylammonium, and formamidinium. Here, we present a multi-technique experimental and theoretical study of structural phase transitions, structural phases and dipolar dynamics in the mixed methylammonium/dimethylammonium MA1-xDMAxPbBr3 hybrid perovskites (0 ≤ x ≤ 1). Our results demonstrate a significant suppression of the structural phase transitions, enhanced disorder and stabilization of the cubic phase even for a small amount of dimethylammonium cations. As the dimethylammonium concentration approaches the solubility limit in MAPbBr3, we observe the disappearance of the structural phase transitions and indications of a glassy dipolar phase. We also reveal a significant tunability of the dielectric permittivity upon mixing of the molecular cations that arises from frustrated electric dipoles.

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Section: Methodsmentioning

confidence: 99%

Suppression of phase transitions and glass phase signatures in mixed cation halide perovskites

et al. 2020

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“…The Agilent 8714ET vector network analyzer was used for this purpose. The dielectric permittivity can be obtained according to the elementary theory of transmission lines which can be found elsewhere [11].…”

Section: Dielectric Spectroscopymentioning

confidence: 99%

Dielectric relaxation and ferromagnetic resonance in magnetoelectric (Polyvinylidene-fluoride)/ferrite composites

et al. 2015

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In this work the dielectric properties and ferromagnetic resonance of Polyvinylidene-fluoride embedded with 10 wt. % of NiFe 2 O 4 or Ni 0.5 Zn 0.5 Fe 2 O 4 nanoparticles are presented. The mechanisms of the dielectric relaxation in these two composites do not differ from each other. For more precise characterization of the dielectric relaxation, a two dimensional distribution of relaxation times was calculated from the temperature dependencies of the complex dielectric permittivity. The results obtained from the 2D distribution and the mean relaxation time are found to be consistent. The dynamics of the dielectric permittivity is described by the Arrhenius law. The energy and attempt time of the dielectric relaxators lie in a narrow energy and time region thus proving that the single type chains of polymer are responsible for a dispersion. The magnetic properties of the composites were investigated using the ferromagnetic resonance. A single resonance line was observed for both samples. From the temperature dependence (100 K -310 K) of the resonance field and linewidth, the origin of the observed line was attributed to the NiFe 2 O 4 and Ni 0.5 Zn 0.5 Fe 2 O 4 superparamagnetic nanoparticles. By the external magnetic field, the angular dependence of the resonance was observed, indicating the magnetic dipolar in-plane interactions.

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“…It is easy to show that (8) and (9) Sign // in (8) Parasitic inductance is considered to be a function of the sample radius , whereas the parasitic and fringe capacitances are functions of the sample length (we used mm). If the radius of the inner conductor , as a first approximation one can consider (10) where and -constants, which can be obtained experimentally by performing measurements of samples with different dimensions and known parameters. The second way to obtain the shapes of all three unknown dependences is electrodynamic modeling of the MC employing specialized software.…”

Section: Model Of the Measurement Circuitmentioning

confidence: 99%

“…This is especially important in the gigahertz frequency range. Furthermore, this model takes into account the distribution of the electromagnetic field in the measuring capacitor (MC) without solving a complicated electrodynamics problem, which generally involves complex calculations (e.g., [9] and [10]). The only feature of this method, which, in some particular cases, could be considered as a shortcoming, is that it requires the knowledge of a full two-port scattering matrix.…”

Section: Introductionmentioning

confidence: 99%

Broadband Method for the Determination of Small Sample's Electrical and Dielectric Properties at High Temperatures

Kežionis

Kazlauskas

Petrulionis

et al. 2014

IEEE Trans. Microwave Theory Techn.

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A model for a measurement circuit consisting of a telescopic coaxial transmission line with the sample placed in the gap of the central conductor has been developed and a measurement method, based on this model, was tested. To determine the sample's electrical properties, the method requires the measurement of the two-port scattering matrices of the short-circuited line, the line with one calibration sample, and the line with the sample to be measured inserted. The model takes into account the thermal elongation of the measurement line and can be used for measuring electrical properties of materials at high temperatures in the megahertz and gigahertz ranges. This model also reduces the influence of parasitic reflections in the measuring coaxial line on the measurement results and takes into account a complicated distribution of the electromagnetic field in the measuring capacitor without solving a complicated electrodynamics problem.

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High Frequency Measurements of Ferroelecrics and Related Materials in Coaxial Line

Cited by 23 publications

References 0 publications

Suppression of phase transitions and glass phase signatures in mixed cation halide perovskites

Suppression of phase transitions and glass phase signatures in mixed cation halide perovskites

Dielectric relaxation and ferromagnetic resonance in magnetoelectric (Polyvinylidene-fluoride)/ferrite composites

Broadband Method for the Determination of Small Sample's Electrical and Dielectric Properties at High Temperatures

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