BARIUM SELENIDE

Description

Barium selenide has the molecular formula of BaSe and the molecular weight of 216.2956 g/mol. Its CAS number is 1304-39-8. It is a white crystalline powder having a melting point of 1782°C. Its density is 5.02 g/cm³. It reacts with water so that an aqueous method of precipitation cannot be used to prepare this compound. Barium selenide is very moisture sensitive, and must be handled under inert conditions. It can be prepared by reaction of the oxide or carbonate with Se, or by the reduction of the selenate with hydrogen gas:
2BaCO3+ 5Se+ Heat ? 2BaSe+ 3SeO2+ CO2
BaSeO4+ 4H2 ? BaSe+ 4H2O
Strontium selenide and barium selenide both have a simple cubic structure, with cube edges equal to 3.117? and 3.308 ? , respectively.

Chemical properties

Crystalline powder. Decomposes in water.

The Uses of BARIUM SELENIDE

Barium selenide has been used to construct a photocell that has been used extensively to measure the solar irradiance of the Sun at various points on the globe. It is used because other photocell elements like selenium tend to decline in output and saturate under the intense radiance of the Sun. BaSe remains quasi-linear and can be used to measure intensity from 2000 ? to 7200 ? using a double monochrometer as a spectrum analyzer. As a portable unit, it uses narrowband (20–50 ? halfwidth) interference glass filters in 14 steps as a spectrum analyzer over the range 3100 ? to 16,300 ? , but the recording is manual. The field of view is <3° of the solar irradiance over the face of the Sun.
BaSe is available commercially as a sputtering target or in limited quantities as a powder.

The Uses of BARIUM SELENIDE

In photocells, semiconductors.