US Patent 6972985 Memory element having islands

A memory including a memory element having islands is provided. The memory has address decoding circuitry and an array of memory plugs. The memory plugs include memory element that have island structures of a first material within the bulk of a second material. The island structures are typically nanoparticles. The memory plugs can be placed in a first resistive state at a first write voltage, placed in a second resistive state at a second write voltage, and have its resistive state determined at a read voltage.