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Updated: Aug 5, 2026
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Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
Published on: November 21, 2019
Orientation-Controlled Bi26-x-yCoxFeyO40/MgO/Si Thin Films: Enhanced Magneto-Optical Performance
Cheng Wang1,2, Jiafang Xie1,2, Teng Gao2
1College of Chemistry, Fuzhou University, Fuzhou350108, P.R. China.
ACS Applied Materials & Interfaces
|July 27, 2026
Summary
A new MgO buffer layer prevents interdiffusion in magneto-optical (MO) films on silicon, significantly enhancing film quality and optical device performance for integrated nonreciprocal optical devices.
Area of Science:
- Materials Science
- Optoelectronics
- Thin Film Technology
Background:
- Integrated nonreciprocal optical devices on silicon (Si) face challenges due to interdiffusion at magneto-optical (MO) film/Si interfaces.
- This interdiffusion degrades film quality and compromises optical performance.
Purpose of the Study:
- To investigate the effectiveness of an MgO buffer layer in suppressing interdiffusion between Bi$_{26-x-y}$Co$_{x}$Fe$_{y}$O$_{40}$ (BCFO) thin films and Si substrates.
- To improve the properties of BCFO thin films for practical nonreciprocal optical devices.
Main Methods:
- Radio-frequency (RF) magnetron sputtering was used to deposit BCFO thin films on Si substrates with and without an MgO buffer layer.
- Structural and interfacial characterizations were performed to analyze the films and interfaces.
Main Results:
- The MgO buffer layer effectively suppressed interdiffusion of Si and Fe/Co.
- MgO buffering promoted preferred orientation in BCFO films.
- MgO-buffered films showed a 38% decrease in surface roughness, a 1.5x increase in saturation magnetization, and a fivefold increase in magnetic circular dichroism (MCD) signal.
Conclusions:
- The MgO buffer layer significantly improves the quality and properties of BCFO thin films on Si.
- MgO-buffered BCFO films show great potential for the development of practical nonreciprocal optical devices.
