Abstract
Measurements were made of the spin-lattice relaxation time of the ground state of in Ca, Sr, and Ba over the magnetic field range of 1 to 12 kG and temperature range of 1.3 to 20°K. The one-phonon relaxation process was unambiguously identified by its characteristic fourth-power dependence on frequency and its linear temperature dependence. The Raman process with its dependence begins to dominate the relaxation above 5°K. The angular dependence of the relaxation permitted the separation of the effect of the two local modes, and , on the one-phonon process. Calculations were in good agreement with theory, and they showed that the second-order terms of the orbit-lattice interaction dominate the relaxation process. Continuous measurement of the relaxation over this magnetic field range was made possible by a technique which is independent of any microwave sources. The detection was done by monitoring the magnetic circular dichroism of the broad optical absorption bands.
- Received 11 August 1969
DOI:https://doi.org/10.1103/PhysRevB.1.2028
©1970 American Physical Society