Surface-Mediated Spin Locking and Thermal Unlocking in a 2D Molecular Array.

Area of Science:

• Materials Science
• Surface Science
• Molecular Electronics

Background:

• Conventional spin crossover complexes often require low temperatures and have short high-spin state lifetimes.
• Molecule-based devices require stable spin states for functionality.

Purpose of the Study:

• To investigate the spin state behavior of nickel phthalocyanine interacting with a copper electrode.
• To explore the potential for non-volatile spin bistability in molecule-based devices.

Main Methods:

• Fabrication of a 2D molecular array of nickel phthalocyanine on a copper metal electrode.
• Characterization of spin state properties using valence spectroscopy.
• Analysis of surface-induced effects on molecular spin states.

Main Results:

• Nickel phthalocyanine on copper exhibits stable coexistence of high-spin and low-spin states without external stimuli.
• Surface-induced axial displacement of nickel cores creates two stable spin states.
• Spin state conversion to low-spin state is triggered by high temperature, with distinct electronic structure changes.

Conclusions:

• The studied nickel phthalocyanine system demonstrates extreme non-volatility and controllable spin bistability.
• This system is highly promising for applications in molecule-based information storage devices.
• Surface interactions are key to achieving stable, room-temperature spin state control.