Nonvolatile memory elements may include a first electrode, a second electrode, a first buffer layer, a second buffer layer and a memory layer. The memory layer may be between the first and second electrodes. The first butter layer may be between the memory layer and the first electrode. The second buffer layer may be between the memory layer and the second electrode. The memory layer may be a multi-layer structure including a first material layer and a second material layer. The first material layer may include a first metal oxide which is of the same group as, or a different group from, a second metal oxide included in the second material layer.