Optical Writing of Magnetic Properties by Remanent Photostriction

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Investigating multiferroic materials like Bismuth Ferrite (BiFeO3) for novel electronic applications.
• Exploring the interplay between ferroelectric, ferromagnetic, and photovoltaic properties in hybrid structures.

Purpose of the Study:

• To demonstrate optically induced remanent photostriction in BiFeO3.
• To utilize this photostriction to modify the ferromagnetism of an adjacent Nickel (Ni) film.
• To explore the potential for light-mediated control of magnetic properties for memory and spintronic applications.

Main Methods:

• Fabrication of a hybrid BiFeO3/Ni structure.
• Optical induction of photostriction in BiFeO3 via the photovoltaic effect.
• Measurement of changes in magnetic coercivity of the Ni film.
• Electrical reversal of the photoferromagnetic effect using static or AC electric fields.

Main Results:

• Achieved a 75% change in coercivity of the Ni film through optical and nonvolatile control.
• Demonstrated that the photoferromagnetic effect is reversible via electrical depolarization of BiFeO3.
• Established that strain-dependent magnetic property changes can be written optically and erased electrically.

Conclusions:

• Optically induced remanent photostriction in BiFeO3 can effectively modify the ferromagnetism of Ni films.
• This light-mediated straintronics approach enables nonvolatile, low-power, multistate control of magnetic elements.
• The findings are relevant for developing advanced memory and spintronic devices.