ESR investigation of the dynamical behavior of hydrogen atoms in CaF ₂

The techniques of ESR are employed to investigate the motion of H atoms in the lattice of CaF2. It is found that the atoms are quite stable against motion at temperatures below 100°C but migrate readily through the lattice at temperatures > 114°C. The character of the initial decrease in intensity of the spectrum seems to be "bimolecular." Later stages are exponential, and are governed by an activation energy of 1.2 eV.