The temperature dependence of the Cotton-Mouton effect and magnetooptical properties of gaseous nitrogen monoxide

HeNe laser measurements of the magnetic birefringence of gaseous nitrogen monoxide in the temperature range between -85 and 120°C and at different pressures below 1·4 bar are reported and analysed in terms of a semiclassical quantum statistical theory. The polarizability anisotropy, Δα = α‖ - α⊥ = 0·844(10) × 10-24 cm3, the anisotropy of the first magnetic hyperpolarizability, Δβ = β‖ - β⊥ = 3·3(6) × 10-33 cm3 G-1, and the corresponding parameter of the second hyperpolarizability, Δη = -2·9(32) × 10-42 cm3 G-2, were obtained for the 2Π ground state while constraining the zero-field molecular parameters and the g-factors to the known spectroscopic values and the magnetic susceptibility anisotropy to ζ‖ - ζ⊥ = -17·2(8) × 10-30 cm3 which was derived from other sources. Δβ is the first numerically known parameter of this kind. Δα agrees with literature Rayleigh scattering results which indicates that the imaginary contribution to the polarizability tensor of NO is negligibly small.