“…However this mechanism is unlikely to be important in many other cases since it requires a relatively high local symmetry, which is easily destroyed by irregularities such as occur in inverse spinels. As the degeneracy is gradually removed there is a transition to the types of mechanisms discussed in previous sections and a smaller anisotropy results (see for example, Bickford, Brownlow and , Pearson 1959, Kaminow 1960).…”