Résonance ferrimagnétique des ferrites et grenats à température de compensation

Ferrimagnetism

“…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).…”

“…. (5.18) This is a hyperbola which in general has four roots of H, in any given frequency I w / 2 ~ 1, but two can be eliminated on physical grounds (Dreyfus 1955 b, PaulevC, Dreyfus andSoutif 1959). I n this equation the signs have been so chosen that all quantities denote absolute magnitudes except y1 and y 2 which are intrinsically negative for electronic moments.…”

Antiferromagnetic and Ferrimagnetic Resonance

“…The ferrite Lio.5Cr125Fe1>250 4 has a compensation point near 60° C [99] and McGuire [100] and van Wieringen [101] observed exchange effects in this region based on the discussion of Wangsness [102]. Further experiments in G dIG [106] and E rIG [107,108] have also been presented by Pauleve et al These showed marked changes in the effective £-value near the compensation region as expected. Further experiments in G dIG [106] and E rIG [107,108] have also been presented by Pauleve et al These showed marked changes in the effective £-value near the compensation region as expected.…”