Memory element and memory device

A memory element, comprising:

• a first electrode, a memory layer, and a second electrode in this order,
• wherein,
• the memory layer includes a resistance change layer including a plurality of layers varying in diffusion coefficient of mobile ions, and an ion source layer disposed between the resistance change layer and the second electrode,
• the resistance change layer includes a first layer on a first electrode side, and a second layer between the first layer and the ion source layer,
• the diffusion coefficient of the mobile ions in the first layer at room temperature is 1.0×1021 m2/s or smaller, and
• the second layer includes one or more of silicon (Si), aluminum (Al), nickel (Ni), palladium (Pd), manganese (Mn), iron (Fe), cobalt (Co), calcium (Ca), magnesium (Mg), gadolinium (Gd), zinc (Zn), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), and lanthanum (La), and includes one or more of oxygen (O), tellurium (Te), sulfur (S), and selenium (Se).

A memory device, comprising:

• a plurality of memory elements each 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 includes (a) a resistance change layer comprising at least a first layer and a second layer, the first and second layers having different diffusion coefficients of mobile ions, and (b) an ion source layer disposed between the resistance change layer and the second electrode, and
• the second layer is between the first layer and the ion source layer, the second layer comprising one or more of oxygen (O), tellurium (Te), sulfur (S), and selenium (Se).