SU427392A1 - CERAMIC MATERIAL - Google Patents

Description

This invention relates to ceramic ferroelectric materials having electro-optical properties. The material can (Find application as a control element in modulators of a beam of optical quantum generators and, in perspective, in optical electron-counting machines.

Ceramic materials used in the form of single crystals are known: KHgPO, LiNbOs, PbMgi,, Nb.y Oz, PbZn, / Bc Oz The first two are characterized by high control voltages, low electro-optical coefficients, and the rest do not allow samples of high optical quality. quite large in size. Growing all monocrystalline elements with a long duration requires folded equipment. Along with this, it is not possible to obtain samples of any shape and size, as well as smoothly change properties in the right direction.

The purpose of the invention is to create an electro-optical ceramic material with sufficient transparency, with high electro-optical coefficients and low control voltages with an expression of thermal stability of properties.

To achieve this goal, a ceramic material of the following composition is proposed:

; cPbMg ,,;, Nb (1 -.t) PbZn Nb., /., Oz, with X 0.9-0.5 forming solid solutions.

For preparation, oxides are taken in the following amounts (wt.%):

lead oxide67,2-68,4 (PSA)

niobium oxide 26.7-27.1 (OFS)

magnesium oxide 2.0-3.7 (PSA)

oxide cy.nka0.8-4.1 (OFS)

The material is milled in an agate mill with the same bites in an alcohol medium before passing through a No. 005f3 sieve. After drying at 120-il50 ° C, the material is pressed into and subjected to the first firing at 850 ° C with aging at this temperature for 2-4 hours. Then the briquettes are crushed and the mass is ground again in an agate spherical mill up to 10 hours in an alcohol medium before passing through a jYo 0056 sieve. From the resulting mass at a specific pressure of 900 kg, samples in the form of disks of diameters of 15 mm are pressed. The final calcination is carried out by hot pressing at 1150-1170 ° C with a specific pressure of 200 kg cm for up to two hours. After grinding to a predetermined thickness and polishing with diamond paste (0 0.3 μm, the material is annealed at 700 ° C with a holding

3

10 min. Naios t silver or translucent 5p20z electrodes.

For example, take oxides in the ratio (wt.%):

67.2

Sviltsa 26.7 Niobium 2.0 Magic 4.1. price list

The obtained ceramic material has the following properties in the range of the television works

from -26 to + 75 ° С at a wavelength of 6240 A.

- The maximum half-wave voltage, U / 2, is necessary to create a difference of the optical path equal to half and;

waves for samples of unit sizes, 0.8 kV,

- the minimum value of quadratic electro-optical coefficients (K} i -) at a frequency of 50 Hz - 27 10-units. CGSE.

For comparison, the relevant characteristics of the above single crystals at room temperature are given.

In the drawing, the temperature dependences of the electro-optical coefficients are given. The proposed ceramic material (curve /) shows a higher thermal stability than PbMgi / Nbs / Qj and PbZnij МЬ2 / Oz single crystals (curves 2 to 3, respectively). The maximum change in RH-Ri in the temperature range from -25 to -f 75 ° C is 13 10- 50-ilO and 20-. CGSE respectively.

; "-". "" Ceramic material based on solid 20 PbMg solutions. / Oz - PbZn d Nb 2 Oz containing lead, niobium, magnesium and zinc oxides as starting components, characterized in that , in order to increase the values of electro-optical coefficients 25

(CGS of the material and thermal stability of its properties, the components are taken in the following ratio of SNRG o /. 67,: 2-68.4 lead oxide 26.7-27.1 niobium oxide .2.0-3.7 magnesium oxide 0.8 -4,1 zinc oxide