A method is provided for programming a memory cell in a memory array. The memory cell includes a resistivity-switching layer of a metal oxide or nitride compound, and the metal oxide or nitride compound includes exactly one metal. The method includes programming the memory cell by changing the resistivity-switching layer from a first resistivity state to a second programmed resistivity state, wherein the second programmed resistivity state stores a data state of the memory cell. Numerous other aspects are provided.