[NCNR/NIST] Investigating the Role of Magnetic Inhomogeneities and Interdiffusion in Compensated Gadolinium Iron Garnet

Thin film magnetic insulators provide an opportunity to realize magnetic non-volatile memories (i.e. spintronics) that consume less energy than traditional metallic based spintronics due to a lack of charge current. The ferrimagnetic iron garnet class of materials (M3Fe5O12) are of particular interest due to the desirable and highly tunable magnetic properties.Y3Fe5O12 (YIG) is the prototypical garnet and most widely studied, however, YIG has been widely reported to have growth issues due to interdiffusion, and further does not have a compensation temperature. Gd3Fe5O12 is a ferrimagnetic garnet that has a compensation temperature near room temperature, and we propose it may be less susceptible to interdiffusion with GGG substrates. We propose to use neutron reflectometry to probe the chemical and magnetic depth profile of GdIG thin films above and below its compensation temperature.

薄膜磁性绝缘体为磁非易失性存储器（即自旋电子学（spintronics））的实现提供了契机：相较于传统金属基自旋电子学器件，此类存储器因无需电荷电流而能耗更低。亚铁磁铁石榴石类材料（M3Fe5O12）凭借其优异且高度可调谐的磁性能而备受关注。钇铁石榴石（Y3Fe5O12，YIG）是典型的石榴石体系，也是目前研究最为广泛的材料，但已有大量研究报道YIG存在因元素互扩散导致的生长缺陷，且其不具备补偿温度。钆铁石榴石（Gd3Fe5O12，GdIG）是一种亚铁磁石榴石，其补偿温度接近室温，我们推测其与GGG衬底之间的互扩散程度更低。本研究拟采用中子反射术（neutron reflectometry），表征GdIG薄膜在补偿温度上下的化学与磁学深度分布。