A. K. Abass

Absorption edge measurements in chemically deposited pyrite FeS2 thin layers

Thin layers of pyrite FeS2 are prepared by chemical deposition using the spray pyrolysis technique. Optical absorption data for photon energies between 1 and 3.8 eV are analyzed and interpreted in terms of electronic transitions and assisting phonons. A direct forbidden band gap of 1.95 ±0.004 eV, an indirect band gap of 1.12±0.003 eV, and assisting phonons of 0.065 eV are detected.

Neutron‐irradiation effect on the absorption edge of NaBrO3 single crystals

Single crystals of sodium bromate are prepared from an aqueous solution of pure material. The effect of neutron irradiation on the absorption edge and indirect band‐gap energy, as well as phonon‐assisted indirect transitions, are studied in the low‐absorption region.