Localized Control of Curie Temperature in Perovskite Oxide Film by Capping-Layer-Induced Octahedral Distortion

Area of Science:

• Materials Science
• Condensed Matter Physics
• Thin Film Technology

Background:

• Ultrathin films offer easier property modification compared to bulk materials.
• Strain engineering via substrates is a known method for controlling perovskite oxide film properties.
• Modifying the oxygen octahedral structure presents an alternative route for developing multifunctional perovskites.

Purpose of the Study:

• To control structural oxygen octahedral rotation in ultrathin perovskite SrRuO3 films.
• To investigate the effect of a SrTiO3 capping layer on SrRuO3 film properties.
• To explore local control of film properties using lithographic patterning.

Main Methods:

• Deposition of a SrTiO3 capping layer on ultrathin SrRuO3 films.
• Lithographic patterning of the capping layer for local control.
• Characterization using scanning Sagnac magnetic microscopy.
• Synchrotron X-ray diffraction for structural analysis.

Main Results:

• Successfully controlled oxygen octahedral rotation in SrRuO3 films via SrTiO3 capping.
• Demonstrated an increase in the Curie temperature of SrRuO3.
• Suppression of octahedral rotations was correlated with the observed increase in Curie temperature.
• Lithographic patterning enabled local control over film properties.

Conclusions:

• A capping-layer-based technique can effectively control structural rotations in ultrathin perovskite films.
• This method enhances the Curie temperature of SrRuO3 by suppressing octahedral rotations.
• The technique provides a new avenue for developing functional oxide materials with tailored properties.