SU1693462A1 - Method of determination of surface tension at the interface between working electrode and solid electrolyte - Google Patents

Abstract

The invention relates to instrumentation engineering, in particular, to means of studying surface electrochemical phenomena at the interface between a solid electrode and a solid electrolyte, and can be used in the electronics industry for developing radio components using surface acoustic waves. The aim of the invention is to increase the detection sensitivity. The solid electrolyte is brought into contact with the working and auxiliary electrolytes. Alternating current is passed through the working electrode - solid electrolyte interface at different interface potential. The oscillations of the solid electrolyte are measured, from which the surface tension is determined. In this case, the working and auxiliary electrodes are installed on both sides of the solid electrolyte. The working electrode is made in the form of a system of plates arranged in parallel and at the same distance from one another. The frequency of the alternating current is set to the frequency of the acousto-synchronism of the working electrode – solid electrolyte system, and the surface acoustic wave in the solid electrolyte, t silt, is measured.

Description

The invention relates to instrumentation engineering, in particular, to means of studying surface electrochemical phenomena at the interface between a solid electrode and a solid electrolyte and can be used in the electronics industry to develop radio components using surface acoustic waves,

The aim of the invention is to increase the detection sensitivity.

The drawing shows a diagram of the device for implementing the method.

The device for determining the surface tension consists of a sample 1 of solid electrolyte in the form of a plate, on one side of which a working electrode 2 is installed, made in the form of a system of plates arranged in parallel and at the same distance from one another. On the opposite side of sample 1 of solid electrolyte, an auxiliary electrode 3 is installed. A series of even and odd plates of working electrode 2 is connected respectively to the extreme points of two series-connected inductors 4, to which is also connected a source

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5 AC. The midpoint of inductances 4 is connected to the auxiliary electrode 3 through the generator 6 of the linearly increasing voltage. The device also contains a mechanical vibration meter of the solid electrolyte sample 1, made in the form of a sensor of surface-acoustic waves.

The method is carried out as follows.

The source of the linearly rising voltage 6 with the help of the auxiliary electrode 3 through the same inductance 4 coils changes the potential at the boundary of the working electrode 2 with the sample 1 solid electrolyte. Since the inductances 4 are the same, have the same resistance, the series of even and odd plates of the working electrode 2 is also under the same DC potential. When the potential changes, the surface tension forces at the interface between the working electrode 2 and the solid electrolyte sample 1 change. This boundary is also acted upon by alternating current from an AC source 5. At the same time, a number of even and odd plates of the working electrode 2 are excited prothiophase. The action of alternating current at the interface causes a change in surface tension forces. This change in surface tension forces acts in antiphase on the interfacial surface of the p even and odd plates of the working electrode 2 with a sample of 1 solid electrolyte.

Thus, mechanical oscillations occur in the solid electrolyte sample 1. Mechanical oscillations are greatly enhanced if the frequency of the alternating current source is set to the frequency of acoustosynchronism. The frequency of the sound-synchronism in this case is determined by the formula:

f V / 2d,

where f is the frequency of acoustosynchronism, Hz;

V is the speed of sound in solid electrolyte, cm / s;

c is the distance between the electrode plates on the surface of the electrolyte, see

In this case, the acoustic oscillations emitted at the interface of each plate of an even and odd row of a working electrode with a solid electrolyte are in phase with vibrations coming from the other plates of their row. In this case, the mechanical vibrations are formed in phase and amplified, and a surface acoustic wave propagates over the surface of the electrolyte sample 1. By

The surface of a solid (more precisely, near the surface of a solid) can propagate several types of waves. In this case, the Rayleigh-type wave will propagate along the electrolyte surface, since the wave vector is characterized by the absence of a normal component to the surface of the electrolyte plate, and the components of the displacements in the wave attenuate with distance from the propagation surface to the inside of the electrolyte. The wave vector is determined by the surface tension forces at the interface between the solid electrolyte and the solid electrolyte, which do not have a normal component to the plane of the electrolig plate. The damping conditions of the component of the displacement of the surface acoustic wave are almost the same as the thickness of the electrolyte plate, which is comparable to the length of the acoustic surface wave in the electrolyte.

To determine the surface tension, a surface acoustic wave is measured from the plane of the electrolyte surface. In order to obtain information on surface tension, it is necessary to know the change in the amplitude and phase of a surface acoustic wave when the potential changes across a solid electrode — solid ejectrolit. In this case, the forces that excite a surface acoustic wave are increments of the surface tension due to the excitation of the solid interface. electrode with solid electrolyte alternating current. Therefore, the forces exciting the surface acoustic wave determine the surface tension derivative, in this case by charge, the surface acoustic wave carries information about the surface tension derivative at the boundary under study, and the phase change determines the sign of the surface tension derivative.

Measurement of the surfaces of an acoustic wave can be carried out using well-known technical means: a wedge transducer of surface oscillations into volume waves with their subsequent conversion into an electrical signal using a piezo sensor, optical methods of measurement, etc. The shape of the curve of the derivative of the surface tension at the studied boundary B is recorded as a function of the DC potential at this pressure. On this dependence, during further processing, characteristic points (maxima, minima, sign reversal) and DC potentials are revealed, which correspond to these characteristic points, which, finally, allows drawing conclusions about the nature of electrochemical processes going on the border.

Claims (1)

The invention The method of determining the surface tension at the boundary of the working electrode with a solid electrolyte is that the solid electrolyte is brought into contact with the working and auxiliary electrolytes, passing an alternating current through the boundary of the working electrode - solid electrolyte at different potential of the interface and measuring oscillations 0 solid electrolyte, which determines the surface tension, characterized in that, in order to increase the detection sensitivity, the working and auxiliary electrodes are installed on both sides of the solid electrolyte, the working electrode is made in the form of a system of plates arranged in parallel and at the same distance from each other, set the frequency of the alternating current equal to the frequency of the acousto-synchronization of the system working electrode - solid electrolyte and measure the surface acoustic wave in the solid electrolyte . ill 1 1 T , C 4 .TTL -P h 1