RU2626390C1 - Method for determining nature of dielectrics' conduction - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: method for determining the nature of dielectrics' conduction is based on verifying the feasibility of the Faraday's law by passing an electric current through a stack of samples of the dielectric under test and determining the quality and quantity of the displaced substance. A stack of samples of the dielectric under test is exposed to electromagnetic radiation, directing the vector of the field energy flux density along the axis of stack of samples of the dielectric under test.

EFFECT: providing the possibility of more accurate determination of the quantity of moving charges and obtaining data on the dielectrics' conduction over a wide frequency range.

1 dwg

Description

The invention relates to methods for determining the nature of the conductivity of dielectrics, for example, glasses.

Published information sources describe methods for determining the nature of the conductivity of dielectrics.

In the work [A.S. No. 395789. A method for determining the nature of the conductivity of dielectrics. Authors: A.A. Deshkovskaya, N.M. Bobkova, A.L. Gribkov, V.P. Stompel and L.D. Soshin. Published on 08/28/1973. Bull. Number 35. IPC G01R 27/26.] Describes a method for determining the nature of the conductivity of dielectrics, based on checking the feasibility of the Faraday law, characterized in that an electric current is passed through a solid dielectric sample and the quality and quantity of electrolysis products released on the electrodes are determined.

Based on the first Faraday law, under the influence of an electric field, ions move along a sample of material and are released on electrodes, the analysis of which determines the number of transferred ions.

The disadvantage of the presented method is its complexity: before the start of the experiment, a metallized layer of electrodes is applied to the surface of the test sample, and then after the experiment, the metallized layer is removed and the change in the additional substance is analyzed. The disadvantage of this method is that the sample is subjected to additional mechanical and chemical influences when applying and removing coatings. When applying and removing metallized coatings, mass is lost and therefore the presence of a newly formed substance in the coating material can be analyzed, but its quantity can be accurately estimated.

Closest to the claimed is a method for determining the nature of conductivity, based on the Tubandt method, described in [Borisova M.E., Koykov S.N. Physics of dielectrics. Textbook Allowance. - L .: Publishing house Leningrad. University. 1979. 240 pp.], In which an electric circuit with an electric energy source is connected to metal plates, between which a stack of three samples of the test material is laid and a direct electric current is passed. Under the action of a contact source of energy of an electric field, charged particles moving from sample to sample change their weight in accordance with the first Faraday law of electrolysis. After the experiment, the weight of the samples is compared before and after the experiment. According to the results of measurements of the weight of the samples, the sign of the charge carriers and their properties are determined.

The disadvantage of this method is that to determine the conductivity of dielectrics a contact source of electrical energy is used, connected to metallized plates to which an electric current is supplied. In this case, the movement of ions occurs not only between the samples, but also from the contact plates to the samples of the tested dielectric, polluting them, which complicates the analysis of experimental data and reduces the measurement accuracy [Borisova ME, Koykov SN Physics of dielectrics. Textbook Allowance. - L .: Publishing house Leningrad. University. 1979. S. 64]. In addition, in the proposed method, only direct current is used as an energy source, which limits the capabilities of researchers.

The aim of the invention is to improve the accuracy of determining the number of moving charges and obtain data on the conductivity of dielectrics in a wide frequency range.

This is achieved by the fact that the inventive method for determining the nature of the conductivity of dielectrics, based on checking the feasibility of the Faraday law, by passing an electric current through a stack of samples of the tested dielectric and determining the quality and quantity of the transferred substance, characterized in that the stack of samples of the tested dielectric is subjected to electromagnetic radiation, direct vector of the field energy flux density along the axis of the stack of samples of the tested dielectric.

In the inventive method, the test dielectric is exposed to electromagnetic radiation contactlessly, and with respect to the direction of the vector of the energy flux of the field along the axis of the stack of samples of the tested dielectric, the direction of movement of the charges is determined, while the charge carriers do not go outside the samples and are not added from outside, there are no contaminants of the samples, which improves the purity of the experiment and increases the accuracy of determining the amount of displaced substance in comparison with the known methods for determining the nature of the conduct bridges.

In FIG. 1 shows a device that implements the inventive method, in the form of a circuit of a single-frequency cell of a waveguide type, at a frequency of 10 GHz, to determine the nature of the conductivity of dielectrics. The diagram shows: 1 - a microwave generator with a waveguide output of 23 × 10 mm emitting in the mode of continuous oscillations, 2 - waveguide rotation along a wide wall (E - corner), 3 - waveguide valve, 4 - waveguide section, 5, 6, 7 - a stack of three polished samples of the tested dielectric, 8 - a shorted segment of the waveguide with an absorbing insert.

The device operates as follows.

The microwave generator in continuous oscillation mode 1 emits an electromagnetic field, which along the waveguide 2 through the waveguide valve 3 and the waveguide section 4 is directed to the stack of samples of the test dielectric 5, 6, 7, passes through them, and then gets into the shorted section of the waveguide with the absorption insert 8 .

The size of the test samples corresponds to the cross section of the waveguide 23 × 10 mm, completely overlapping its cross section with minimal gaps, and the contact surfaces of the samples are polished, withstanding high plane parallel surfaces. The selected waveguide connection scheme allows creating conditions for the propagation of an electromagnetic wave in a waveguide, in which the field energy flux density vector (Poiting vector) is directed along the axis of the stack of samples of the tested dielectric.

Before the start of the experiment, the samples of the test dielectric are dried in a vacuum oven, weighed, stacked and introduced into the waveguide section, the stack of samples of the tested dielectric is exposed to electromagnetic radiation, the field energy flux density vector is directed along the axis of the stack of samples of the tested dielectric. The waveguide section is isolated from the external atmosphere by radio-transparent dielectric spacers at the joints between the waveguide sections, which is especially important due to the long time of the experiment. After the experiment, the samples are removed from the waveguide section and weighed. A change in the weight of the samples characterizes the type of conductivity of the dielectric. By weighing the samples, it is established which ions, positive or negative, are charge carriers and to what extent ionic conductivity prevails over electronic.

Using waveguide lines, it is possible to conduct studies in a wide frequency band from 0.3 GHz to 200 GHz [A.L. Feldstein, L.R. Yavich, V.P. Smirnov. Guide to the elements of waveguide technology. M., Soviet Radio, 1966, 653 pp.]. Since it is assumed that there is no energy gradient that promotes the transfer of matter in the direction perpendicular to the Poiting vector, the use of waveguide lines does not reduce the measurement accuracy.

Charged particles inside the material in an alternating electromagnetic field are mobile under the action of the Gaponov-Miller force [Demyantseva, S.M. Kuzmin, M.A. Solunin, S.A. Solunin, A.M. Solunin. On the motion of charged particles in an alternating inhomogeneous electric field. Journal of Theoretical Physics. Volume 82, no. 11, 2012, p. 1-10.] In the direction or opposite of the Poyting vector.

In the nonrelativistic case, only a force acting along the Poyting vector acts on the particle. This follows from Newton’s equation, the motion of a particle in an electromagnetic field [L.D. Landau, E.M. Lifshits. Theoretical Physics: Textbook. benefits In 10 volumes. T. 2. Field Theory. - 7th ed. corrected - M .: Because of Science. 1988, 512 pp.]:

,

,

where c is the speed of light

e is the particle charge,

m is the mass of the particle,

E and H are the electric and magnetic field vectors,

v is the particle velocity.

If the particle velocity is small, the particle is not relativistic and the transverse component of the force is absent, and the average force (Gaponov-Miller) acts on the particle in the alternating field.

In the case of relativistic particles, the movement of charges in the waveguide along its axis may not be observed due to the appearance of transverse forces [R.A. Castillo, V.P. Milantiev. Averaged forces acting on a relativistic particle in a waveguide. // Applied Physics. 2011, No.6. S. 68-73].

The speed of ions in a dielectric is small and definitely not relativistic.

The force acting on charge carriers, the stronger, the greater the energy absorbed by them [D.V. Sivukhin. General physics course. Textbook: For universities. In 5 t. T. IV. Optics - 3rd edition of stereotypes. - M.,: FIZMATLIT, 2005. - P. 559], therefore, the mass transfer of charges is studied under various conditions, for example, in the frequency band or under the influence of temperatures.

For a more in-depth calculation of the experimental results, the algorithm described in [B.M. Bolotovsky, A.V. Serov. On the peculiarities of the motion of charged nonrelativistic particles in an alternating field. // Advances in physical sciences. 1994, Volume 164, No. 5, pp. 545-547],

In the inventive method for determining the conductivity of dielectrics, it is possible to carry out measurements without using guide lines, for example, in free space, without contacting the samples of the investigated dielectric at the end boundaries.

As a result of experiments using a series of cells tuned to different frequencies, the dependence of the conductivity of the investigated dielectric in the frequency band is obtained.

To determine the dependence of the change in the conductivity of the investigated dielectric on temperature, the section with the samples is placed in a furnace.

The inventive method for determining the nature of the conductivity of dielectrics includes the necessary features to ensure that all technological operations of the measurement process are carried out, and differs from known analogues in higher measurement accuracy.

Thus, a positive effect was achieved, consisting in increasing the accuracy of measuring the conductivity of dielectrics in a wide frequency range of an alternating electromagnetic field.

Claims (1)

A method for determining the nature of the conductivity of dielectrics, based on checking the feasibility of the Faraday law, by passing an electric current through a stack of samples of the tested dielectric and determining the quality and quantity of the transported substance, characterized in that the stack of samples of the tested dielectric is exposed to electromagnetic radiation, the field energy flux density vector is directed along axis of the stack of test dielectric samples.

Images