Phonon-Engpaß und sein Einfluß auf die paramagnetische Relaxation.

The coupled spin-lattice and lattice-bath differential equations are solved numerically for the special case of terbium ethyl sulfate. The relaxation decay shows non-exponential behaviour if the lifetime τ of the phonons in direct contact with the spin-system is equal or greater than T/b. T is the spin-lattice relaxation time and b the ratio of the specific heats of the spin-system and the phonons in contact with the spin-system. The effective (measured) relaxation time T depends on the initial disturbance of the spin-system. In a second paper measurements are published which show these predicted effects. In these experiments there has been found a severe phonon bottleneck in the terbium ethyl sulfate. [ABSTRACT FROM AUTHOR]