OPTICAL CONSTANTS VERSUS PURITY IN EUTE AND EUSE

Measurements of absorption coefficient and refractive index at room temperature on single crystals of EuTe and EuSe show a significant correlation between their degree of purity, the infrared absorption and the refractive index. The Kramers-Kronig relations applied to the infrared absorption do not explain the unusual sensitivity of the refractive index to non-stoichiometry. The optical constants appear especially suitable for purity controls of the europium chalcogenides. © 1969.