Electron spin-echo studies of hydrogen- and gadolinium-doped calcium fluoride

Investigation of relaxation phenomena using two-pulse and three-pulse electron spin-echo technique was carried out on hydrogen- and gadolinium-doped single-crystal calcium fluoride. Measurements were made on calcium-fluoride crystals singly doped with H⁰ and Gd³⁺ and doubly doped with both H⁰ as well as Gd³⁺. Echo decay functions and phase memory times were determined in the 1.2-2.2 ^∘{}K temperature range. The results are interpreted using existing theories of electron spin-echo decay. A discussion of the results and of deviations from theories is presented. Three-pulse spin-echo decay measurements are also used to determine the spinlattice relaxation time of spins in the 5/2↔3/2Gd³⁺ cubic line in CaF₂.