FARADAY EFFECT IN CUBIC CRISTALS

Abstract

The magneto-optic rotation has been measured in five cubic crystals KCI, KBr, KI, LiF and MgO for a number of wavelengths from y 5780 A to A 2848 A. Dispersion formulae have been proposed for both optical refraction and magnetic gyration. The formula for magnetic gyration fits the experimental data to within 1/2%. It is found in the case of alkali halides that all the absorption wavelengths, characteristics of the substances,are effective towards the magnetic gyratioa in the same proportion as in refraction, i.e., the value of the anomaly factor for different absorption frequencies are the same. But the values of anomaly factor are definitely less than unity (which is the value to be expected of atoms and ions having the inert gas structure) and they are -85, -85, -87 and -84 for KCI, KBr, KI, LiF respectively. In MgO, the value of the anomaly factor for A 1300 A is found to be .96, while that for the other wavelength A 400 A is zero.