| 摘要 |
A composite comprises a particulate electrically conductive material having an average particle size of not more than 1 micron and a non-particulate electrically non-conductive material, wherein the composite exhibits a plasma-like response and has a plasma frequency below that of a bulk metal. The electrically conductive particles may comprise gold, silver, or cobalt and the non-conductive material may comprise paraffin wax or polytetrafluoroethylene. Typically, the conductive particles have an average particle size of 1 nm to 1 micron, especially 100 nm. The composite may exhibit no long range order and may be switchable between radiation propagating and radiation attenuating states. The composite may have a degree of electrical connectivity between regions of conductive particles, which may be changed by application of a stimulus, such as pressure, temperature, chemical absorption, electric field, and electric current. |
