DOUBLE-QUANTUM TRANSITIONS OF MN2+ IN CAO

The Delta M = 2 spin transitions are forbidden in first-order perturba tion theory but allowed in the second order. With electron paramagneti c resonance, we have observed such transitions for Mn2+ in CaO between the M = 1/2 and M = +3/2 levels between the M = -3/2 and M = +1/2 lev els. The intensity dependence of these lines on the energy level spaci ng is in good agreement with theory. In addition, we have observed wea ker lines due to transitions between M = +/-1/2 and M = +/-5/2 levels.