Temperature-Dependent Fermi Gap Opening in the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="italic">c</mi><mo>(</mo><mn>6</mn><mo>×</mo><mn>4</mn><mo>)</mo><mo>–</mo><mrow><msub><mrow><mi>C</mi></mrow><mrow><mn>60</mn></mrow></msub></mrow><mi>/</mi><mi>Ag</mi><mo>(</mo><mn>100</mn><mo>)</mo></math></span> Two-Dimensional Superstructure

C. Cepek; I. Vobornik; A. Goldoni; E. Magnano; G. Selvaggi; J. Kröger; G. Panaccione; G. Rossi; M. Sancrotti

doi:10.1103/PhysRevLett.86.3100

Temperature-Dependent Fermi Gap Opening in the $c (6 \times 4) - C_{60} / Ag (100)$ Two-Dimensional Superstructure

C. Cepek, I. Vobornik, A. Goldoni, E. Magnano, G. Selvaggi, J. Kröger, G. Panaccione, G. Rossi, and M. Sancrotti

Phys. Rev. Lett. 86, 3100 – Published 2 April 2001

Abstract

High-resolution angle-integrated photoemission of one monolayer of $C_{60}$ chemisorbed on Ag(100) shows the reversible opening of a gap at the Fermi level at temperatures $25 \leq T \leq 300 K$ . The gap reaches a maximum value of $\approx 10 meV$ at $T \leq 70 K$ . This finding is the first evidence of an electronic phase transition in $C_{60}$ monolayers and has implications on the ongoing debate about surface superconductivity in $C_{60}$ -based bulk materials.

Received 2 October 2000

DOI:https://doi.org/10.1103/PhysRevLett.86.3100

Authors & Affiliations

C. Cepek¹, I. Vobornik¹, A. Goldoni², E. Magnano¹, G. Selvaggi³, J. Kröger⁴, G. Panaccione¹, G. Rossi^1,3, and M. Sancrotti^1,5

¹Laboratorio Nazionale TASC-INFM, Strada Statale 14, km 163.5 Basovizza, I-34012 Trieste, Italy
²Sincrotrone Trieste S.C.p.A, Strada Statale 14, km 163.5 Basovizza, I-34012 Trieste, Italy
³INFM and Dipartimento di Fisica, Universita' di Modena e Reggio Emilia, Via Campi 213/A, I-41100 Modena, Italy
⁴Physik-Institut der Universität Zürich, CH-8057 Zürich, Switzerland
⁵INFM and Dipartimento di Matematica e Fisica, Universita' Cattolica del Sacro Cuore, Via dei Musei 41, I-25121 Brescia, Italy