On the Problem of Cross Relaxation in Systems with Different Axes of Quantization

Specimens with two different types of spins S and I are considered. There is a slight difference between their Zeeman energies and the dependence of the cross‐relaxation probability (1/ T 12 )on the angle between the axes of spin quantization is considered in the general form. It is shown that 1/ T 12 , increases almost by an order of magnitude when the angle between the axes of spin quantization change from 0 to π. In addition, the problem of cross‐relaxation probability is considered for a system of non‐equivalent non‐Kramers S and I ions (doublets). The dependence of 1/ T 12 on the value of the constant magnetic field and on the parameters Δ of the Hamiltonians of non‐Kramers doublets is obtained. In particular, it is shown that in a simple case 1/ T 12 ∼1/ H   z 4 .