SPIN RELAXATION OF HE-3 TO PARAMAGNETIC CENTERS IN SURFACES AT VERY LOW-TEMPERATURES

The memory function formalism is used to derive a generalized golden rule expression for the spin-lattice relaxation rate 1/T1 for 3He to paramagnetic centers embedded in or residing on surfaces in contact with the 3He. This expression is applied to several simple models of relaxation to paramagnetic spins which do not interact among themselves, both for 3He in the Fermi-liquid phase and for a solid surface layer of 3He on the substrate. The magnitude of 1/T1 is calculated for each case as well as the temperature and magnetic field dependence. Finally, the relationship between the spin-lattice relaxation rate and the Kapitza conductance across surfaces via magnetic interactions is determined. © 1979 Plenum Publishing Corporation.