Altered Mode of Structural Changes in Solid Solutions Leading to Dual Modulation: Spin Transition Temperatures and...

Area of Science:

• Materials Science
• Chemistry
• Physics

Background:

• High-density information storage demands precise control of electron spin states.
• Multistep spin-crossover (SCO) materials offer potential due to multiple stable spin states.
• Controlling SCO dynamics, specifically spin transition temperature (Tc) and transition steps, remains challenging.

Purpose of the Study:

• To develop a novel two-dimensional SCO solid solution system for dual dynamic modulation.
• To achieve fine-tuning of the spin transition temperature (Tc) and control over the number of transition steps.
• To investigate the underlying mechanisms of dual modulation in SCO materials.

Main Methods:

• Synthesis of a two-dimensional SCO solid solution system: [Fe(HL)(L')]·H2O.
• Characterization using single-crystal diffraction analysis.
• Computational analysis using periodic density functional theory (DFT).

Main Results:

• The SCO solid solution system exhibited nonmonotonic variation in Tc with composition, reaching a minimum at a specific doping level.
• Achieved fine-tuning of Tc over a 66 K range and controlled transition steps from two to one.
• Demonstrated that doped ligands modulate the FeIII ligand field, altering structural contraction modes and enabling dual modulation.

Conclusions:

• The proposed SCO solid solution system successfully achieved dual dynamic modulation of SCO behavior.
• Synthetic control of SCO solid solutions via altered structural contraction modes offers a new route for adjusting SCO properties.
• This work advances the development of materials for high-density information storage.