Ultrafast giant magnetic cooling effect in ferromagnetic Co/Pt multilayers.
Je-Ho Shim1,2,3, Akbar Ali Syed2,3, Chul-Hoon Kim2,3,4
1Department of Physics, Chungbuk National University, Cheongju, 361-763, South Korea.
Nature Communications
|October 8, 2017
Summary
Giant magnetic cooling up to 200 K occurs on a femtosecond timescale in cobalt-platinum nano-multilayers. This ultrafast phenomenon, driven by spin alignment via lattice-spin interaction, offers potential for novel magnetic devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Magnetic cooling, an eco-friendly alternative to conventional refrigeration, relies on entropy changes from magnetization alignment.
- The ultimate timescale of magnetic cooling has remained unexplored.
- Ultrafast magnetic cooling could revolutionize magnetic device technology.
Purpose of the Study:
- To investigate the timescale of the magnetic cooling effect.
- To explore giant magnetic cooling phenomena in Co/Pt nano-multilayers.
- To assess the potential for ultrafast magnetic devices.
Main Methods:
- Time-resolved magneto-optical response analysis.
- Systematic variation of laser fluence, external magnetic field strength, and direction.
- Investigating photoinduced demagnetization and remagnetization dynamics.
Main Results:
- A giant magnetic cooling effect of up to 200 K was observed.
- This cooling occurs on an ultrafast femtosecond timescale.
- Rapid spin alignment via lattice-spin interaction in Co/Pt nano-multilayers drives the effect.
Conclusions:
- Ultrafast giant magnetic cooling is achievable in Co/Pt nano-multilayers.
- The findings open new avenues for developing ultrafast magnetic devices.
- The study establishes a femtosecond timescale for magnetic cooling.
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