Memory element with ion source layer and memory device

A memory device, comprising:

• a plurality of memory elements. each memory element including a first electrode, a memory layer, and a second electrode in this order;
• and
• a pulse application section applying a voltage or current pulse selectively to the memory elements,
• wherein,
• the memory layer of each memory element includes
• (a) a resistance change layer containing an oxide, and
• (b) an ion source layer comprising a stacking structure of two or more unit ion source layers, each unit ion source layer including a first layer and a second layer, the first layer containing (i) chalcogen elements of tellurium (Te), sulfur (S), or selenium (Se) or any combination of them and (ii) an easy-to-move element that is easy to move in the memory layer, the first layer having a non-uniform distribution of the easy-to-move element from the first electrode to the second electrode, the second layer containing a difficult-to-move element that is difficult to move in the memory layer, the easy-to-move element being able to diffuse more easily into the memory layer than the difficult-to-move element.