US Patent 9111609 Concentric phase change memory element

The present invention in one embodiment provides a memory device including a first electrode; a second electrode; and a memory cell positioned between the first electrode and the second electrode, the memory cell including a core of a first phase change material and a cladding of a second phase change material, wherein the first phase change material has a lower crystallization temperature than the second phase change material. The present invention also provides methods of forming the above described memory device.