石榴石的铁磁共振线宽△H、有效线宽△H_(eff)及自旋波线宽△H_k  

The Linewidth △H, Effective Linewidth △H_(eff) and Spinwave Linewidth △H_k of Some Garnets

作　　者：韩志全[1] 任仕晶[1] 

机构地区：[1]西南应用磁学研究所,四川绵阳621000

出　　处：《磁性材料及器件》2009年第4期6-11,18,共7页Journal of Magnetic Materials and Devices

摘　　要：Dy:YGdIG(DyxY3-b-z-xGdzCabGebInaFe5-a-bO12)的△H,△Heff,△Hk与Dy取代量呈线性增加关系。随饱和磁化强度Ms的增加Dy:YGdIG的优值系数Fhp(≈(2ω/ωm)(δ△Hk/δ△Heff))和δ△Heff/δ△Hk值均呈线性下降。CaGe:YGdIGs(Y2-xGd1.0CaxGexInaFe5-a-xO12)的△H,△Heff,△Hk随Ge含量的增加而线性增大,可分别用Ms的下降进行解释。由CaGe:YGdIGs和YBiCaVIGs的△H,△Heff与Ms的关系得出△Heff∝Ms-0.8(YBiCaVIG),Ms-1.4(YGdCaGeIG)的实验规律,与非共振△Heff的晶粒表层自旋波共振激发模型较为一致。由Gd:YIG(GdxY3-xFe5O12),Gd:YCaGeInIG(GdxY3-x-aCaaGeaInbFe5-a-bO12)实验,发现少量CaGeIn的取代可使YGdIG的△H明显降低而不影响△Hk。由不同晶粒尺寸样品的hc(H)蝶形曲线,发现了阶梯状蝶形曲线,讨论了晶粒尺寸对△Hk、hc(H)蝶形曲线的影响,以及拐点磁场与理论Hmin之间的差距。The △H, △Heff and △Hk values of Dy：YGdIGs（DyxY3- b-z-xGdzCabGebInaFe5-a-bO12） increase linearly with increasing Dy content x. The ratio of δ△Heff/δ△Hk and the figure of merit Fhp（=2ω/ω）（δ△Hk/δ△Heff） of the Dy：YGdIGs decrease linearly with increasing Ms. The linear increase of △H, △Heff and △Hk with increasing Ge content for the CaGe：YGdlnlG （Y2-xGd1.0CaxGexInaFe5-a-xO12） are presented and explained by the decrease of Ms. Based on the dependence of △H and △Heff on Ms for the CaGe：YGdIGs and BiYCaVIGs, the regulations of △Heff^∝ Ms^-1.4 for CaGe：YGdlnlG and △Heff^∝CMs^-0.8 for YBiCaVIGs are obtained, which consist with the model of spin wave resonance exited in the grain-surface-layers for the △Heff off resonance. From experiments of Gd：YIG （GdxY3-xFe5O12） and Gd：YCaGelnlG （GdxY3-x ,CaaGeaInbFe5-a-bO12）, it was found that a small amount of substitution of CaGeln to YGdlG can lower the △H, and result in no change in △Hk. The butterfly curve of nonlinear threshold he（H） for parallel pumping was investigated on samples with various rough or fine grains. A stepped shape of butterfly curve was observed. The influence of grain size on the △Hk and hc（H） butterfly curve and the separations between the knee field and Hmin theoretical value are discussed.

关 键 词：Dy:YgdIG 石榴石 铁磁共振线宽△H 有效线宽△Heff 自旋波线宽△Hk 高功率临界场Hc(H) 饱和磁化强度Ms 

分 类 号：TM277.3[一般工业技术—材料科学与工程] O482.5[电气工程—电工理论与新技术]