Angular Momentum Compensation in Narrow Linewidth Ferrimagnets

Abstract

Studies are described of the ferrimagnetic garnet system Eu₃Fe_5—xGa_xO₁₂. It is shown that a compensation point of the net angular momentum occurs at x≅1.2, at which the resonance linewidth remains narrow. In all previously observed ferrimagnetic systems with angular momentum compensation points, e.g. GdIG, strong line broadening occurs. The reasons for this are discussed together with the relaxation processes involved. Application of the resulting large g factors to millimeter wave harmonic generation is considered.