Improving Magneto-Optical Properties of Nd0.5Bi2.5Fe5O12 Thin Films by Introducing Bi3Fe5O12 Underlayer

To improve the magneto-optical properties of Nd0.5Bi2.5Fe5O12 (Bi2.5:NIG) thin films, a Bi3Fe5O12 (BIG) underlayer was introduced. Bi2.5:NIG thin films with a thickness of 150 nm were prepared on Nd2BiFe4GaO12(Bi1Ga1:NIG)/BIG layers prepared on glass substrates, and Bi2.5:NIG/BIG layers were prepared on Gd3Ga5O12(GGG)(100) substrates, where all samples were prepared by using the metal-organic decomposition method. The Faraday rotation angle at around a wavelength of 520 nm significantly increased from 16.7°/μm to 31.5°/μm for Bi2.5:NIG/Bi1Ga1:NIG/BIG/glass and from 18.5°/μm to 27.8°/μm on Bi2.5:NIG/BIG/GGG. We consider the improvement in the Faraday rotation angles of these samples’ BIG underlayer to have enhanced the epitaxial growth of Bi2.5:NIG, resulting in an improved crystallinity and Faraday effect for the Bi2.5:NIG thin films.