Determination of the magnetoelectric coupling coefficient from temperature dependences of the dielectric permittivity for multiferroic ceramics Bi5Ti3FeO15

2013 ◽  
Vol 117 (5) ◽  
pp. 875-878 ◽  
Author(s):  
J. A. Bartkowska ◽  
J. Dercz
Keyword(s):  
Dielectric Permittivity ◽  
Coupling Coefficient ◽  
Magnetoelectric Coupling ◽  
Temperature Dependences

The Determination of the Magnetoelectric Coupling Coefficient in Ferroelectric–Ferromagnetic Composite Based on PZT–Ferrite

2013 ◽  
Vol 58 (4) ◽  
pp. 1401-1403 ◽  
Author(s):  
J.A. Bartkowska ◽  
R. Zachariasz ◽  
D. Bochenek ◽  
J. Ilczuk
Keyword(s):  
Dielectric Permittivity ◽  
Coupling Coefficient ◽  
Mean Field ◽  
Field Approximation ◽  
Theoretical Description ◽  
Magnetoelectric Coupling ◽  
Mean Field Approximation ◽  
Dielectric Measurements ◽  
Temperature Dependences ◽  
Multiferroic Composite

Abstract In the present work, the magnetoelectric coupling coefficient, from the temperature dependences of the dielectric permittivity for the multiferroic composite was determined. The research material was ferroelectric-ferromagnetic composite on the based PZT and ferrite. We investigated the temperature dependences of the dielectric permittivity (") for the different frequency of measurement’s field. From the dielectric measurements we determined the temperature of phase transition from ferroelectric to paraelectric phase. For the theoretical description of the temperature dependence of the dielectric constant, the Hamiltonian of Alcantara, Gehring and Janssen was used. To investigate the dielectric properties of the multiferroic composite this Hamiltonian was expressed under the mean-field approximation. Based on dielectric measurements and theoretical considerations, the values of the magnetoelectric coupling coefficient were specified.

Experimental determination of the magnetoelectric coupling coefficient via piezoelectric measurements

2008 ◽  
Vol 19 (4) ◽  
pp. 045106 ◽  
Author(s):  
M Vopsaroiu ◽  
M Stewart ◽  
T Hegarty ◽  
A Muniz-Piniella ◽  
N McCartney ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Coupling Coefficient ◽  
Magnetoelectric Coupling

The Determination of Electrokinetic Coupling-Coefficient and Zeta Potential of Rock Samples by Electrokinetic Measurements

2012 ◽  
Vol 516-517 ◽  
pp. 1870-1873 ◽  
Author(s):  
Jun Wang ◽  
Heng Shan Hu
Keyword(s):  
Zeta Potential ◽  
Coupling Coefficient ◽  
Streaming Potential ◽  
Potential Method ◽  
Surface Conductivity ◽  
Reliable Estimate ◽  
Surface Conductance ◽  
Streaming Current ◽  
Low Concentrations

The electrokinetic effects are important in the understanding of electric properties in porous medium. In this study, the streaming potential and streaming current of saturated samples are measured at different concentrations, then three methods are applied to obtain the zeta-potential and electrokinetic coupling coefficient. The study shows that the results obtained from streaming potential and streaming current methods agree well with each other, but the results obtained from simplified streaming potential method become seriously inaccurate at low concentrations due to the influence of surface conductance. This experimental study also provides a reliable estimate of the surface conductivity and its contribution to zeta-potential at given concentrations.

scholarly journals Seven-Rod Dielectric Sensor for Determination of Soil Moisture in Small Volumes

Proceedings ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 49
Author(s):  
Justyna Szerement ◽  
Aleksandra Woszczyk ◽  
Agnieszka Szypłowska ◽  
Marcin Kafarski ◽  
Arkadiusz Lewandowski ◽  
...  
Keyword(s):  
Dielectric Permittivity ◽  
Sandy Loam ◽  
Sample Volume ◽  
Small Sample ◽  
Silt Loam ◽  
Frequency Range ◽  
Fem Simulations ◽  
Dielectric Sensor ◽  
Permittivity Spectrum

The paper presents the performance of a seven-rod dielectric probe for determination of soil dielectric permittivity using FEM simulations as well as FDR and TDR measurements. The volume of the sensitivity zone of the tested probe was assessed basing on the simulations and measurement in liquids. The probe was also tested in two soils, sandy loam and silt loam. The obtained results suggested that the seven-rod probe can be used to accurately measure the dielectric permittivity spectrum in a small sample volume of about 8 cm3 in a frequency range from 20 MHz to 200 MHz.

Measurement of Complex Dielectric Permittivity of Quartz Systems

2019 ◽  
Vol 946 ◽  
pp. 129-133
Author(s):  
Vitaly Smolko ◽  
Elizaveta Antoshkina
Keyword(s):  
Aqueous Solution ◽  
Dielectric Permittivity ◽  
Polyvinyl Alcohol ◽  
Specific Surface ◽  
Ultrasonic Treatment ◽  
Complex Dielectric Permittivity ◽  
Active Centers ◽  
Sand Surface ◽  
Quartz Sands

The article describes the problem of the experimental determination of complex dielectric permittivity for natural, activated, and modified quartz systems. The results of determination of specific surface, complex dielectric permittivity, sands porosity are presented in this article. The authors obtained the empirical equation of complex dielectric permittivity calculation for natural, activated, and modified quartz sands, taking into account the effect of moisture, specific surface, porosity, impurities content into consideration. The modification of the sand surface by means of mechanical beneficiation and ultrasonic treatment leads to reduction of complex dielectric permittivity and specific surface, thus contributing to the increase of the active centers quantity on the sands surface. The modification of the sand surface by polyvinyl alcohol aqueous solution leads to increase of complex dielectric permittivity. Polyvinyl alcohol aqueous solution modification envisages the creation of new active centers by oligomers inoculation to the surface and blocking the clay component and authigenous film ingredients. Among the considered methods, ultrasonic treatment in aqueous solution and mechanical beneficiation are the most efficient and technologically acceptable ways of activation.

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