| abstract |
An electrically operated, directly overwritable memory element (42) comprising a volume of memory material (36) having at least two electrical resistance values. The volume of memory material can be set to one of the resistance values in response to a selected electrical input signal without the need to be set to a specific starting or erased value. The memory element includes resistive layers (31, 41) for controlling the distribution of electrical energy within the memory material, heating layers (34, 38) for transferring heat energy into the memory material, and thermal insulation layers for reducing the loss of heat energy from the memory material. |