STUDY OF SPIN-LATTICE RELAXATION IN THE EXCITED TRIPLET-STATES OF IMPURITY MOLECULAR-CRYSTALS INDUCED BY SPIN-ORBITAL INTERACTION

The spin-lattice relaxation mechanism based on the energy modulation o f spin-orbital interaction has been investigated in the triplet excite d states of impurity molecular crystals. This modulation emerges as a result of the admixture of the rotational motions of a molecule and th e vibrational motions of nuclei to the translational molecular motions at the acoustic lattice vibrations. In the framework of this spin-lat tice relaxation mechanism the direct one-phonon processes are studied at low temperatures and in high magnetic fields. The calculations of a ngular, field and temperature dependences of the spin-lattice relaxati on rates for a real deuterobenzophenone crystal with an isotopic impur ity were carried out using the molecular oribital and atom-atom potent ial methods.