【摘要】 本文对钇-镧石榴石型铁氧体系Y_3（1-x）La_3xFe₅O₁₂（其中x=0,0.05,0.10,O.20,0.30,0.50,0.75和1.00）的磁性和铁磁共振进行了研究。由X射线粉末照相分析和金相观察确定了石榴石转构的单相区域。测量了饱和磁矩б_s、起始磁导率μ₀、矫顽力H_c及有效g因子geff和共振线宽△H（3970和9160兆赫）与La含量x的关系。由磁性和铁磁共振的测量结果表明单相区城要比由X射线分析和金相观察的结果更窄一些。讨论了不同成分的б_s的变化,μ_O与磁化机构的关系。由geff与频率的关系计算出内场H_i和材料的内禀g因子。从磁的不均匀性的观点解释了实验上观测到的△H、H_i和H_C在一定成分范围内与x的指数式关系。更多还原

【Abstract】 The magnetic properties and Ferromagnetic resonance of the yttrium-lanthanum iron garnet system Fe5O12 were investigated at the compositions corresponding to x=0, 0.05, 0.10, 0.20, 0.30, 0.50, 0.75 and 1.00. The single-phase region with garnet structure determined by the X-ray powder pattern analysis and metallographic observations extends to about 0.10<x<0.20. However, magnetic and ferromagnetic resonance observations indicate a somewhat narrower single-phase region. The saturation magnetic moments per gram σs, initial permeability zzμ0, coercive force Hc, effective g-factors geff and resonance line-width△H (at 3970 and 9160 Mc) were measured as a function of composition. The variation of σs with composition and the magnitude of σ0 as viewed from various magnetization mechanisms were discussed. From the frequency dependence of geff, the intrinsic g-factors and internal fields Hi of the materials were calculated. Exponential dependence of AH, H; and Hc on x in certain composition region was observed experimentally and interpreted from the point of view of magnetic inhomogene-ities.更多还原