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Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals
Published on: August 15, 2018
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Magnetoelectric Response in Multiferroic SrFe12O19 Ceramics
Guolong Tan1, Yao Huang1, Haohao Sheng1
1State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, China.
Plos One
|December 10, 2016
Summary
Strontium hexaferrite (SrFe12O19) ceramics exhibit room-temperature ferroelectricity, ferromagnetism, and a giant magnetocapacitance effect. Oxygen annealing enhances these properties by converting Fe2+ to Fe3+, enabling novel electronic device applications.
Area of Science:
- Multiferroic materials science
- Solid-state chemistry
- Condensed matter physics
Background:
- Multiferroic materials exhibiting simultaneous ferroelectric and ferromagnetic properties are rare.
- Strontium hexaferrite (SrFe12O19) is a well-known magnetic material, but its ferroelectric and magnetocapacitive properties are less explored.
Purpose of the Study:
- To investigate the co-existence of ferroelectricity, ferromagnetism, and magnetocapacitance in SrFe12O19 ceramics.
- To understand the role of oxygen annealing on the multiferroic properties of SrFe12O19.
Main Methods:
- Synthesis of SrFe12O19 ceramics with subsequent heat treatment in an oxygen atmosphere.
- Characterization using techniques such as polarization-electric field (P-E) hysteresis loops, current density-electric field (J-E) measurements, dielectric spectroscopy, X-ray photoelectron spectroscopy (XPS), and magnetic measurements.
Main Results:
- Demonstrated intrinsic ferroelectricity with a saturated polarization hysteresis loop and a remnant polarization of 103 μC/cm².
- Observed strong ferromagnetism with a coercive field of 6192 Oe and remnant magnetic moment of 35.8 emu/g.
- Reported a giant magnetocapacitance effect with a maximum change in dielectric constant of 1174% upon application of a magnetic field.
Conclusions:
- Oxygen annealing is crucial for inducing ferroelectricity and enhancing ferromagnetism in SrFe12O19 by transforming Fe2+ to Fe3+ and reducing oxygen vacancies.
- The co-existence of ferroelectricity, ferromagnetism, and a giant magnetocapacitance effect at room temperature makes SrFe12O19 a promising candidate for advanced electronic devices.
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