Figure 1.

Core–shell structure bimetallic nanowire geometry. ε1, ε2, ε3are the dielectric functions for the metallic core, metallic wall and embedding regions, respectively;r1denotes the core radius andr2denotes the wall radius

Zhu Nanoscale Research Letters 2009 4:977-981   doi:10.1007/s11671-009-9344-4