PURITY OF BORON PREPARED BY VACUUM DECOMPOSITION OF PURIFIED BORON TRIIODIDE.

Article abstract of DOI:10.1016/0022-5088(79)90106-1

The synthesis, purification, and thermal decomposition of boron triiodide have been investigated as a method for preparing high purity boron. Using spark source mass spectrography for the analyses of bulk samples, the purity of boron is studied as a function of the purification treatments applied to BI//3 prior to its decomposition. Bisublimation, recrystallaization and, to a higher degree, zone refining of BI//3, result in a noticeble decrease in the levels of almot all impurities except carbon and oxygen. The lowest contamination levels attained are 200 and 470 wt. ppm for carbon and oxygen, respectively, and a total content of 150 wt. ppm for the other main impurities.