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Updated: Sep 3, 2025
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Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
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Photoinduced Persistent Polarization Change in a Spin Transition Crystal
Sheng-Qun Su1, Shu-Qi Wu1, Yu-Bo Huang1
1Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
Angewandte Chemie (International Ed. in English)
|July 30, 2022
Summary
Researchers discovered a new way to control crystal polarization using light. This study shows a spin crossover crystal changing its polarization when exposed to green light, opening doors for optoelectronic materials.
Area of Science:
- Solid-state chemistry
- Materials science
- Crystallography
Background:
- Controlling crystal polarization with light is typically achieved indirectly via pyroelectric effects.
- Directly modulating crystal polarization through light-induced electronic band excitation is an underexplored area.
Purpose of the Study:
- To investigate a novel photoinduced macroscopic polarization change in an Fe(II) spin crossover crystal.
- To explore the potential of polar spin crossover systems in optoelectronics.
Main Methods:
- Photoexcitation of an Fe(II) spin crossover crystal with green light.
- Detection of pyroelectric current upon relaxation to the ground state.
- Structural, magnetic, Mössbauer, and infrared spectroscopic analysis, supported by theoretical calculations.
Main Results:
- The Fe(II) spin crossover crystal demonstrated a significant photoinduced macroscopic polarization change upon green light excitation.
- A detectable pyroelectric current was observed as the crystal returned to its ground state.
- Analysis revealed that ion movement during the spin transition process drives the polarization change.
Conclusions:
- Light can directly modulate crystal polarization by exciting electronic bands, leading to spin transitions.
- The observed simultaneous spin transition and polarization change highlight the potential of polar spin crossover materials for optoelectronic applications.
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