Computational method on magnetic properties of microwave ferrimagnets

Central to microwave applications are iron garnet type materials involving rare earth elements. Most commonly they are based on Gd-Al substitutions-typically Y_3-3xGd_3xFe_5-5yAl₅O₁₂ , offering wide temperature ranges of stable magnetic susceptibility, along with other desirable manufacturing characteristics. We were particularly interested in the coefficient of stability of magnetisation α=(4π M_max^S-4π M_min^S)/(4π M _23°C^S) (Δ T^-1) and the temperature regions [T₁-T₂], ΔT=T₂-T₁ for which it is minimised. They determine their technological applications of the specific garnet materials; we established their location and α_min for temperature ranges from 60° through 180°C (in increments of 30°C.) Extensive experimental studies of a variety of Gd-Al garnets demonstrate that all key magnetic parameters change in a liner manner as functions of Gd contents and Al contents. This suggests that the susceptibility curves (and computations) for new, yet to be synthesised Gd-Al garnets, can be generated through a suitable linear interpolation of the known compounds. We offer a computer-aided verification of this hypothesis followed by CAD of garnet type materials