US Patent 7332765 Variable resistance functional body and storage device

A variable resistance functional body has an insulator interposed between a first electrode and a second electrode and interposed between a third electrode and a fourth electrode. The insulator contains a plurality of conductive particles. The conductive particles are formed by implanting a substance for forming the conductive particles into the insulator by the negative ion implantation method. The conductive particles are provided so that an electrical resistance between the third electrode and the fourth electrode changes on the basis of a size effect or a change in size between before and after application of a prescribed voltage across the first electrode and the second electrode.