Spin Uncoupling in Free Nb Clusters: Support for Nascent Superconductivity

Authors

Ramiro Moro, Georgia Institute of Technology
Shuangye Yin, Georgia Institute of Technology
Xiaoshan Xu, University of Nebraska-LincolnFollow
Walt A. de Heer, Georgia Institute of Technology

Date of this Version

2004

Document Type

Article

Citation

PHYSICAL REVIEW LETTERS VOLUME 93, NUMBER 8

Comments

Used by permission.

Abstract

Molecular beam Stern-Gerlach deflection measurements on Nb clusters (Nb_N, N <100) show that at very low temperatures the odd-N clusters deflect due to a single unpaired spin that is uncoupled from the cluster. At higher temperatures the spin is coupled and no deflections are observed. Spin uncoupling occurs concurrently with the transition to the recently found ferroelectric state, which has superconductor characteristics [Science 300, 1265 (2003)]. Spin uncoupling (also seen in V, Ta, and Al clusters) is analogous to the reduction of spin-relaxation rates observed in bulk superconductors below T_c.