Abstract

A newly developed optical hole-burning technique gives direct access to the nuclear spin conversion rate between the methyl group tunneling levels in the solid state and allows a comparison between the tunneling splitting in different electronic states. Using low temperature techniques spin conversion in dimethyl-s-tetrazine doped single crystals of durene could be followed for over more than 10⁶ s. The relaxation data show below 4 K a transition from an Orbach to a Raman type temperature law as has been predicted by theory.

© 1992 Optical Society of America