SU948973A1 - Batch for ferroelectric ceramic material - Google Patents

Description

one

The invention relates to electronic equipment and can be used to make ceramic capacitors.

At present, both in domestic and in foreign capacitor manufacturing, barium titanate-based materials are used mainly for the manufacture of ferroceramic capacitors. However, these materials have either not enough high dielectric constant or temperature stability d € / € 2.o in the range of operating temperatures is not good enough.

For industry, it is necessary to have monolithic capacitors with a temperature stability of the capacitance in the temperature range -60 - within ± 1 Q%.

Known capacitor ferroelectric material on the basis of a solid solution of the system VaTrs-V O TY with additives and SbO. with a dielectric constant of 1250-1 50. Thin-film monolithic capacitors made of this material have a capacitance stability in the temperature range of -60 + 125 ° C not more than t10%, but not enough high dielectric constant 1.

to

Closest to the invention is the mixture for a ferroelectric material 2, having the following composition, in% by weight:

Barium titanate 9 -97

15

Titanium oxide0,, 6

Niobium Oxide 1.0-2.0

Dysprosium Oxide 0, -2.0

Carbonic acid

Argan 0.1-0,

20

The material made from this mixture has a dielectric constant of 1600-1800 and the capacitance change in the temperature range -60 does not exceed ± 10.

However, the well-known material does not provide the dielectric prestige of more than 1800.

The aim of the invention is to increase the dielectric constant.

This goal is achieved by the fact that the mixture for ferroelectric ceramic material containing barium titanate, niobium and dysprosium oxides and manganese carbon dioxide, additionally contains praseodymium oxide in the following ratio of components, 1% by weight:

Bari titanate 95,, 5

Niobium Oxide 1.0-2.0

Dysprosium Oxide 0.2-2.0

Carbonic

manganese 0.2-0.6

Praseodymium Oxide 0.1-0.9

The reality and optimality of the proposed ratio of ingredients is confirmed by the following examples by their minimum, maximum and average values, wt.

Example 1. Barium titanate in the amount of 95.5 is loaded into the vibromill in the form of powder, then niobium oxide 1.0 is added to it. Dysprosium oxide 2.0, manganese carbonate 0.6 and praseodymium oxide 0.9.

The characteristics of the material in this case are as follows: the dielectric constant of 1810, the change in the dielectric constant in the temperature range of -60 is -3.6.

Example 2. A barium titanate in the amount of 97.5 is loaded into the vibromill in the form of powders, then niobium oxide 2.0, dysprosium oxide 0.2, carbonic acid 0.2 and praseodymium oxide 0.1 are added to it.

The characteristics of the material in this case are as follows; the dielectric constant of 2030, the variation of the dielectric constant in the temperature range of -60 - +125 C is +6.8 - -8.2.

Example 3 A barium titanate in the amount of 96.5 is loaded into the vibromill in the form of powders, then niobium oxide 1.5, dysprosium oxide 1.1, manganese carbonate 0.4 and praseodymium oxide 0.5 are added to it. Characteristics of the material in this case following: dielectric

the permeability g 1915, the change in dielectric permeability in the temperature interval of -60 - is + 5.8-6.3%.

The proposed ferroelectric material obtained as follows.

The components specified in examples 1-3 are mixed in a vibrating mill for 2-F and as a result, a fine powder is obtained, to which is added a solution of polyvinyl alcohol, or solutions of rubber or polyvinyl-buteral, and then samples are obtained either by pressing disks or by casting through a spinnerette. films coated with palladium electrodes. The samples are burned at 13 VWC for 2 hours and receive disk or solid capacitor blanks from the proposed ferroelectric material.

The proposed material has a dielectric constant of 1800-2000. Capacitors made of this material have a high VC stability of capacitance (cT) /

in the temperature range -60 - + 125 ° С. As can be seen from the above data, the dielectric constant of the proposed material is l / 15 higher and is 18002000, while the known material has 6. 1600-1800. The higher dielectric constant of the material proposed leads to significantly higher quality capacitors, since the capacitors in this case have a higher specific capacitance.

In addition, the absence of deficient bismuth oxide in the composition of the proposed material allows to obtain monolithic capacitors with cheaper palladium electrodes, and not with scarce platinum electrodes, which leads to savings in precious metals.

Claims (1)

Invention Formula The mixture for a ferroelectric ceramic material, mainly for the manufacture of monolithic capacitors, containing barium titanate, niobium oxides and dysprosium and manganese carbon dioxide, characterized in that with a view to increasing 53 8373 6 nor the dielectric constant, Sources of information, it additionally contains oxide, taken into account when examining a zeodim in the following ratio components, md: 1. USSR author's certificate Barium titanate 95,5-97,5s №, cl. C 0 V 35/00, 1973 Niobium oxide 1.0-2.0 Dysprosium oxide 0.2-2.02. USSR author's certificate Carbon dioxide manganese 0.2-0.6 (f 692812, class C. B, 1978 Praseodymium oxide 0.1-0.9 {prototype}.