Temperature-dependent fermi gap opening in the c(6x4)-C60/Ag(100) two-dimensional superstructure.

Area of Science:

• Surface Science
• Condensed Matter Physics
• Materials Science

Background:

• Fullerene (C60) monolayers are studied for their unique electronic properties.
• Understanding electronic phase transitions is crucial for developing novel electronic materials.
• The potential for surface superconductivity in C60-based materials remains an active area of research.

Purpose of the Study:

• To investigate the electronic properties of a C60 monolayer chemisorbed on Ag(100).
• To identify and characterize any electronic phase transitions occurring at the Fermi level.
• To explore the implications of these findings for superconductivity in C60 systems.

Main Methods:

• High-resolution angle-integrated photoemission spectroscopy was employed.
• Experiments were conducted on a single monolayer of C60 chemisorbed on a Ag(100) surface.
• Temperature-dependent measurements were performed in the range of 25 K to 300 K.

Main Results:

• A reversible opening of a gap at the Fermi level was observed in the C60 monolayer.
• The electronic gap reached a maximum value of approximately 10 meV at temperatures below or equal to 70 K.
• This represents the first evidence of an electronic phase transition in C60 monolayers.

Conclusions:

• The study demonstrates a temperature-dependent electronic phase transition in C60/Ag(100) monolayers.
• The observed phenomenon provides critical insights into the electronic behavior of C60 surfaces.
• These findings contribute to the ongoing discussion regarding surface superconductivity in C60-based bulk materials.