Interfacial and Bulk Magnetic Properties of Stoichiometric Cerium Doped Terbium Iron Garnet Polycrystalline Thin Films
Interfacial and Bulk Magnetic Properties of Stoichiometric Cerium Doped Terbium Iron Garnet Polycrystalline Thin Films
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DOI：
10.1002/adfm.202000409
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发表时间：
2020-02
影响因子：
19
通讯作者：
Karthik Srinivasan;C. Radu;D. Bilardello;P. Solheid;B. Stadler
中科院分区：
文献类型：
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作者：
Karthik Srinivasan;C. Radu;D. Bilardello;P. Solheid;B. Stadler
溅射沉积的掺铈铽铁石榴石（Ce:TbIG）是光子集成电路中用于光隔离器的最佳磁光包层之一，它具有较大的法拉第旋转（≈- 3500°cm - 1，在1550 nm处）。Ce0.5Tb2.5Fe4.75O12的近理想化学计量量Ce + TbFe = 0.57发现有一个44 nm的磁死层，可以阻碍传播模式与石榴石包覆层的相互作用。Ce:TbIG在Si上的有效各向异性也很重要，但使用体热失配的计算高估了有效各向异性。在这里，X射线衍射测量产生了高度精确的应变测量，显示各向异性有利于平面内磁化，这与Ce:TbIG的正磁致伸缩一致。在TbIG中掺入Ce后，补偿温度略有下降，这表明稀土优先占据了十二面体位，并且不同晶格位之间没有阳离子再分布。高法拉第旋转、大剩余比、大矫顽力和优先的平面内磁化使Ce:TbIG成为平面内锁存石榴石，不受与光传播方向共线的杂散场的影响。
One of the best magneto‐optical claddings for optical isolators in photonic integrated circuits is sputter deposited cerium‐doped terbium iron garnet (Ce:TbIG) which has a large Faraday rotation (≈−3500° cm−1 at 1550 nm). Near‐ideal stoichiometry Ce + TbFe = 0.57 of Ce0.5Tb2.5Fe4.75O12 is found to have a 44 nm magnetic dead layer that can impede the interaction of propagating modes with garnet claddings. The effective anisotropy of Ce:TbIG on Si is also important, but calculations using bulk thermal mismatch overestimate the effective anisotropy. Here, X‐ray diffraction measurements yield highly accurate measurements of strain that show anisotropy favors an in‐plane magnetization in agreement with the positive magnetostriction of Ce:TbIG. Upon doping TbIG with Ce, a slight decrease in compensation temperature occurs which points to preferential rare‐earth occupation in dodecahedral sites and an absence of cation redistribution between different lattice sites. The high Faraday rotation, large remanent ratio, large coercivity, and preferential in‐plane magnetization enable Ce:TbIG to be an in‐plane latched garnet, immune to stray fields with magnetization collinear to direction of light propagation.