Crystallization and stability of rare earth iron garnet/Pt/gadolinium gallium garnet heterostructures on Si

• Published in: Journal of magnetism and magnetic materials 2022-12, Vol.564, p.170043, Article 170043
• Main Authors: Gross, Miela J., Bauer, Jackson J., Ghosh, Supriya, Kundu, Subhajit, Hayashi, Kensuke, Rosenberg, Ethan R., Andre Mkhoyan, K., Ross, Caroline A.
• Format: Article
• Language: English
• Subjects: Crystallization; Magnetic insulators; Rare earth iron garnets; Spintronics
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2022.170043

•50–75 nm thick polycrystalline YDyIG is grown on Si and crystallized with RTA.•Dy:Y ratio affects magnetic characteristics of film as reported model predicts.•Growth and crystallization of YDyIG/Pt/GGG on Si induces agglomeration of Pt.•Ineffective Pt barrier creates diffuse interface of garnet layers in YDyIG/Pt/GGG. The crystallization of rare earth iron garnet films such as dysprosium iron garnet on Si substrates provides a path for integration of these complex oxides into magnetic devices. We report the growth of 50–75 nm thick dysprosium yttrium iron garnet (YDyIG) films, deposited without a seed layer then crystallized by a 750 °C rapid thermal anneal, forming a polycrystalline film with grains of several µm diameter containing radiating low-angle boundaries. The Y:Dy ratio affects the magnetization and anisotropy of YDyIG. Crystallization becomes more challenging as the garnet film thickness decreases. To crystallize thinner rare earth garnet films, tri-layer stacks consisting of a 50 nm thick gadolinium gallium garnet (GGG) seed layer, a 1.5 nm thick Pt diffusion barrier, and a 10 nm thick YDyIG film were prepared. The YDyIG/Pt/GGG tri-layers showed agglomeration of the Pt leading to a morphology consisting of a polycrystalline garnet film enriched with Dy and Fe and containing a layer of Pt nanoparticles embedded near its surface.