Measurement of spin–phonon transition probabilities in ruby

Measurements at X-band frequencies of relaxation times and spin–phonon transition probabilities in ruby grown by the "vapor phase" method were carried out. They demonstrate the existence of relaxation processes which cannot be related to the spin–lattice coupling parameters obtained from ultrasonic and static stress experiments.

MEASUREMENT OF SPIN-PHONON TRANSITION PROBABILITIES IN POTASSIUM CHROMICYANIDE

An experimental method based on the technique of microwave pumping was used to measure spin-phonon transition probabilities in dilute potassium chromi-cyanide. The set of numerical values obtained appears to indicate that the spin-lattice relaxation by the direct process of the cyanide-coordinated Cr3+ ion violates the quadrupolar selection rules. This behavior is in disagreement with the Kronig – Van Vleck theory, but is not contradicted by the experimental results of other workers.