HIGH PRESSURE SYNTHESIS OF NEW COMPOUNDS, BISMUTH DISELENIDE AND BISMUTH MONOSULFIDE MONOSELENIDE,
Abstract
To obtain an essentially quantitative yield of BiSe2, a 1:2.2 atomic ratio of Bi:Se was subjected to 45 kilobars at 1280C for 5-10 minutes. For BiSSe, a mixture of Bi:S:Se in a 1:1.1:1.1 atomic ratio was held at 47 kilobars and 1000C for 5-10 minutes. Both products are stable in water, aqueous ammonia and concentrated HC1 at room temperature, but react rapidly and vigorously with concentrated HNO3. Density determinations on both crude and purified milligram samples ranged from 7.23 to 7.79 g/cc, for BiSe2, and 6.35 to 6.72 g/cc for BiSSe. These materials when heated at 5 degrees per minute in either O2 or N2 decompose, in an initial step, primarily to the corresponding trivalent bismuth compound. With BiSe2, conversion to Bi2Se3 occurred at 275C, as indicated by the X-ray diffraction powder pattern of the residue. BiSSe decomposed above 240C to a material whose X-ray diffraction powder pattern was in agreement with that of the mineral guanajuatite, Bi2(S,Se)3. Although the two compounds are not isomorphs, general agreements apparent in the X-ray diffraction patterns may indicate structural similarities. (Extracted)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1965
- Accession Number
- AD0613638
Entities
People
- Meyer S. Silverman