Nanoscale Magnetic Ordering Dynamics in a High Curie Temperature Ferromagnet

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Sensing

Background:

• Thermally driven magnetic phase transitions exhibit critical behavior with divergent susceptibilities and long-range correlations.
• Probing critical phenomena at relevant length and time scales is challenging for conventional techniques.

Purpose of the Study:

• To investigate the critical behavior of a high-Curie temperature (high-T_c) ferromagnetic oxide near its phase transition.
• To utilize scanning nitrogen-vacancy (NV) center magnetometry and relaxometry for nanoscale analysis.

Main Methods:

• Employing scanning nitrogen-vacancy (NV) center based magnetometry for nanoscale magnetic texture analysis.
• Utilizing all-optical relaxometry to measure temperature-dependent spin dynamics.
• Performing cluster analysis on measured magnetic textures.

Main Results:

• Nanoscale magnetic texture analysis suggests the phase transition belongs to the 3D universality class, with a diverging correlation length near T_c.
• Spin dynamics measurements indicate the phase transition aligns with the XY universality class.
• Successfully captured both static and dynamic aspects of critical behavior.

Conclusions:

• The study provides insights into the universal properties governing magnetic phase transitions.
• Scanning NV center magnetometry and relaxometry are effective tools for probing critical phenomena in magnetic materials.
• The findings contribute to understanding complex magnetic behaviors near the Curie temperature.