Multiferroic Rhodium Clusters

作者:Ma Lei*; Moro Ramiro; Bowlan John; de Heer Walt A
来源:Physical Review Letters, 2014, 113(15): 157203.
DOI:10.1103/PhysRevLett.113.157203

摘要

Simultaneous magnetic and electric deflection measurements of rhodium clusters (Rh-N, 6 <= N <= 40) reveal ferromagnetism and ferroelectricity at low temperatures, while neither property exists in the bulk metal. Temperature-independent magnetic moments (up to 1 mu(B) per atom) are observed, and superparamagnetic blocking temperatures up to 20 K. Ferroelectric dipole moments on the order of 1D with transition temperatures up to 30 K are observed. Ferromagnetism and ferroelectricity coexist in rhodium clusters in the measured size range, with size-dependent variations in the transition temperatures that tend to be anticorrelated in the range n = 6-25. Both effects diminish with size and essentially vanish at N = 40. The ferroelectric properties suggest a Jahn-Teller ground state. These experiments represent the first example of multiferroic behavior in pure metal clusters.

  • 出版日期2014-10-6