SU834777A1 - Resistive material - Google Patents

Description

(54) RESISTANT MATERIAL

eleven

The invention relates to electrical engineering, in particular, to the development of resistive material based on conductive complex titanium oxides and rare earth elements, which can be used as elements of electrical circuits.

A resistive material consisting of titanium sesquioxide, is known.

The disadvantage of the known material is the complex temperature dependence of the electrical resistivity, which in the temperature range 29 (1-473 K decreases from 1 to 10 TEM-cm and then varies like that of metals.

The closest in technical essence to the present invention is a resistive material based on a complex titanium oxide and rare earth element, rare earth orthotitanates of composition 1 and Т 10з, where LU is a rare earth element whose electrical resistivity at 290 K varies from 810 ohms. : cm dl LaTiOj to ohm-cm dl.

However, the rare-earth orthotitanates of rare-earth elements have a high metallic-type electrical conductivity, which is characteristic only of the remaining compounds LuTiO-j, where Lu is a rare-earth element, from Ce to Lu have a higher resistivity of a semiconductor character.

The purpose of the invention is to increase electrical conductivity and expand the range of resistivity.

The goal is achieved by the fact that a resistive material containing a rare earth oxide; titanium dioxide and acetylene black, contains the starting components in the following amounts, wt.%:

The oxide of the rare earth element58, 72-66.99 and 30.69-40.78

Dioxide of titanium 0,3-4,53 L Shetilenova soot

The proposed resistive material is obtained by sintering in vacuum a mixture of titanium dioxide, rare earth oxides and solid carbon used as a reducing agent for Ti. Carbon is taken with a 15-20% excess against stoichiometry. The source material is thoroughly mixed, pressed and calcined first in a low vacuum (Hg) at 1100-1200 ° C until the release of carbon monoxide is stopped, and then in a high vacuum (- Hg, Art.) At 1400 s for 20 25 hours. The product is ground, samples 1 are pressed from it suitable for measuring resistance, which are subjected to re-annealing at 1450 ° C for 12-15 hours. The following is a specific example of how to obtain a resistive material of the proposed composition and its characteristics. Example 1. 6.21 g of cerium dioxide, 4.12 g of titanium dioxide T i and 0.25 g of acetylene black are pereirat, pelletized and calcined in a vacuum of mercury. when the carbon monoxide is completely stopped, and then in a vacuum of Hg, at 1400 ° C for 25 hours. The product is ground, samples are prepared in the form of a parallelepiped of mm size and subjected to additional annealing for 12 hours. Ceg-fiO- containing 59.2 wt.%, W, 0 wt.% T i 0, the rest. The resistivity p at 290 K is. I-id ohm-cm Example 2. 7.2 g of GeO, 3.4 TiOd and 0.5 g of acetylene black are treated as in Example 1. A material of composition Ce ggTiO containing 69.4%, 0.1 riO., Is obtained, the rest with the value of the specific resistance / at 290 K is equal to 9-10 ohm-cm. For example 3. 5.93 rPrgO, 4.11 g of T i 0 / J and 0.03 g of acetylene black are treated as in Example 1. A material of composition Pgr-d TUD containing 59.3%, 37, is obtained 0 ,, the rest. The resistivity P at 290 K is 210 ° Om-cm. Example 4. 6.96 g of Pr.jO, 3.38 g of T i and 0.25 g of acetylene black are treated as in Example 1. A material of the composition containing 69.5% Pr ,, 0.1 is obtained. tiO, the rest is T, 0h, with the value of the specific resistance f at 290 K equal to 1-10 Ohm-cm.

-3

9-10

,

Ilo

, -2

1-10

CETUS Example 5. 5.98 g of Nd, j, 0, 4.06 g of TiOjL and 0.03 g of acetylene black are treated as in Example 1. A material of composition NdojTiO is obtained, containing 59.8%, 36.5% of TiO, ., the rest, with a value at 290 K equal to 8 .. cm. Example 6..7.0 g, 3.40 g of TioD and 0.25 g of acetylene black are treated as in Example 1. A material of the composition Nd TiO-j containing 70.0%, 0.1% TiO is obtained, the rest is TiaO , with a resistivity value of H at 290 K equal to 1-10 cm-cm. Example 7. 6.0 g of 5t / 2rz, 3.97 g of T10, and 0.03 g of acetylene are treated as in Example 1. A material of composition NdqgeTiOs is obtained. containing 64.5%, 22.2%, the rest of LDO-s, with the value of Р at 290 К 1-10-Ohm-cm. Example 8. 7.08 g 5pp2.0a ,, 3.24 g 0.245 g of acetylene calcium are treated as in example 1. A material of the composition containing 64.2%, 0.1% LO, is obtained, the rest, p at 290 K is 1 ohm-cm. The table shows the values of the resistivity of the proposed resistive material of the composition at different values of X (0, 7 x 1.0) and the resistivity of the known resistive material of the composition LuTiO. As follows from the table, the proposed resistive materials based on complex titanium oxides and rare earth elements of the composition Lu; (TiOg, where 0, 7: X 1.0, have a high electrical conductivity of metallic type. The proposed resistive material of the composition at 290 K has 10 100 times higher electrical conductivity than the known resistive material of the composition LuTiOj. A change in the content of rare earth metal in the proposed resistive material provides an extension of the range of resistivity while maintaining the same rarely Gmina Jemielno element. Thus, by varying X in Ns.TiOa from 1.00 to 0.8 produced a material with a resistivity at 290 K ,, a varying in the range 1 2-10 PAR

rare earth oxide, titanium dioxide and acetylene black, characterized in that, in order to increase electrical conductivity and expand the range of specific resistance, it contains initial components in the following amounts, weight:

The oxide of the rare earth element 58,72-66,99

Table continuation

Sources of information taken into account in the examination

1. Japanese Patent 47961, .kl. H 01 B 1/00, 1972.

2.Bazuyev G.V., Shveikin G.P., Izves Academy of Sciences of the USSR. Inorganic materials. 1978, vol. 14, no. 2, 267 (prototype).

Claims (1)

Claim Resistive material containing 20 rare-earth oxide, titanium dioxide and acetylene black, with the fact that, in order to increase electrical conductivity and expand the range of specific resistance, it contains the starting components in the following quantities, wt.%: Rare Earth Oxide 58.72-66.99 Titanium dioxide 30.69-40.78 Acetylene carbon black 0.3-4.53