most common use of the substance "barium oxide" is based on its hygroscopic property - the ability to absorb water.It is therefore directly in the chemical industry, it is used as a component for producing barium peroxide.The industry is indispensable for the production of oxide ceramic magnets.In addition, in the present conditions barium oxide whose formula BaO, I found great application in microelectronics and electrical engineering.For the production of ferrate using magnitokeramiki barium, which is obtained by combining in a strong magnetic field under a pressure of a mixture of powders of oxides of barium and iron.
However, the main focus of the application is the manufacture of thermionic cathodes.At the beginning of the last century, scientists from Germany Venelt studied law electron emission, which was recently opened British researcher Richardson.For experiments Venelt used pieces of platinum wire.The first experimental results fully confirm the conclusions drawn later the British physicist.But then the experience failed and Venelt suggested that the flow of electrons is much higher than normal, because on the surface of the working material - platinum - could appear any impurities.Check your assumption Venelt found that the source of the deviation value of the electron flux is barium oxide, caught on the surface of the platinum in the composition of the lubricant technical devices used in the experiment.Conclusions Venelta long remained unrecognized because the scientific community could not reproduce experimentally his experience.It took nearly a century for the English physicist Kohler proved the correctness Venelta.Kohler on the basis of repeated experiments proved that if barium oxide is subjected to a gradual warm up at low pressure, the intensity of the thermionic emission is increasing rapidly.
only in the thirties of the last century, the German chemist Paul suggested, consists in the fact that electrons are activated because of the presence of impurities in the barium oxide.During the reaction, which is conducted at low pressure, the oxygen escapes from the oxide.Staying with the barium is ionized and thus contributes to the appearance of free electrons.These electrons and were the ones who left the crystal structure when heated and that once watched Venelt.
It was only at the beginning of the second half of the last century was finally proved the validity of this hypothesis.Chemists Bundeli A. and P. Kovtun (USSR) could not only numerically set the value of the impurity concentration of barium oxide, and experimentally compare its value with the value of the flow of thermal emission.That is why the barium oxide is used as active ingredient in the manufacture of thermionic cathodes.As an example, an electron beam with which the generated image on the screen of simple computer monitor or television.As a source of the stream here is barium oxide.
If the substance to try to dissolve in water, it is found that barium oxide reacts with the water by heating the solution.Thus obtained substance barium hydroxide - a white powder with a melting point of 78 ° C.This compound is reacted with an excellent carbon dioxide gas, and therefore an aqueous solution, often referred to as "barite water", is widely used as a reagent to carbon dioxide.
The starting compound and the required component is included in the composition of the various coloring materials, lubricants and oils.This use of barium oxide predicted another DIMendeleev.
