No abstract

The variation of spin-lattice relaxation time (T,) with magnetic field (B) for the Cr 3+ ion in ruby has been measured under non-Kramers conditions for fields between 0.3 and 2.6 tesla, corresponding to microwave frequencies in the range 9 to 71 GHz. Below about 0.8 tesla there is a slow variation, approximately as T1 oc B-0.4; at higher fields the variation becomes more rapid, approaching T, oc B -2.~ at 2.6 tesla. This behaviour is explained in terms of the non-linear divergence of the energy levels with field.