A memory cell comprising: a memory component comprising: a first conductive material (24, 38) comprising a metal; a second conductive material; and an oxide material (28, 40) between the first conductive material and the second conductive material; wherein the memory component is configured to change resistance from a first resistive state to a second resistive state by conduction of a programming current conducted from the first conductive material through the oxide material to the second conductive material, and wherein the current is sufficient to cause electromigration of the metal from the first conductive material into the oxide material; characterised by: a diode comprising a first electrode, a second electrode, and a dielectric material, the diode being connected in series with the memory component so that a current passing through the diode also passes through the memory component; and wherein the first electrode comprises a first metal and the second electrode comprises a second metal different than the first metal. a memory component comprising: a first conductive material (24, 38) comprising a metal; a second conductive material; and an oxide material (28, 40) between the first conductive material and the second conductive material; wherein the memory component is configured to change resistance from a first resistive state to a second resistive state by conduction of a programming current conducted from the first conductive material through the oxide material to the second conductive material, and wherein the current is sufficient to cause electromigration of the metal from the first conductive material into the oxide material; characterised by: a diode comprising a first electrode, a second electrode, and a dielectric material, the diode being connected in series with the memory component so that a current passing through the diode also passes through the memory component; and wherein the first electrode comprises a first metal and the second electrode comprises a second metal different than the first metal. a first conductive material (24, 38) comprising a metal; a second conductive material; and an oxide material (28, 40) between the first conductive material and the second conductive material; wherein the memory component is configured to change resistance from a first resistive state to a second resistive state by conduction of a programming current conducted from the first conductive material through the oxide material to the second conductive material, and wherein the current is sufficient to cause electromigration of the metal from the first conductive material into the oxide material; characterised by: a diode comprising a first electrode, a second electrode, and a dielectric material, the diode being connected in series with the memory component so that a current passing through the diode also passes through the memory component; and wherein the first electrode comprises a first metal and the second electrode comprises a second metal different than the first metal. a diode comprising a first electrode, a second electrode, and a dielectric material, the diode being connected in series with the memory component so that a current passing through the diode also passes through the memory component; and wherein the first electrode comprises a first metal and the second electrode comprises a second metal different than the first metal.