SPIN-LATTICE COEFFICIENTS FOR SUBSTITUTIONAL GD3+ IN CAF2

For the purpose of evaluating the spin-lattice coefficients C11 and C44, for CaF2:Gd3+ in cubic sites, uniaxial stress studies were conducted at room temperature on a single crystal of CaF2 doped with 0.02 at. % Gd3. From the measured shifts of the magnetic field positions of certain of the fine structure components, corresponding to known increments in applied stress, the spinlattice coefficients were evaluated in magnitude and sign. Taking compressive stress as negative, the experimentally determined values are C11 = -2.4 ± 0.8 × 10-13 cm dyn and C44 = -5.5 ± 1.1 × 10-13 cm dyn. © 1969.