Two-terminal reversibly switchable memory device
A memory using mixed valence conductive oxides is disclosed. The memory includes a mixed valence conductive oxide that is less conductive in its oxygen deficient state and a mixed electronic ionic conductor that is an electrolyte to oxygen and promotes an electric filed to cause oxygen ionic motion.
1. A multi-resistive state element comprising:
a conductive element;
a reactive metal that reacts with the conductive element; and
an oxygen repository;
wherein the multi-resistive state element is operable to:
change from a high resistive state to a low resistive state upon application of a first write voltage, and
change from a low resistive state to a high resistive state upon application of a second write voltage.
2. The multi-resistive state element of claim 1 , wherein the reactive metal has fully reacted with the conductive element.
3. The multi-resistive state element of claim 1 , wherein the multi-resistive state element can be exposed to a range of voltages without disturbing a resistive state of the multi-resistive state element.
4. The multi-resistive state element of claim 1 , wherein the multi-resistive state element is substantially non-conductive over a range of voltages from V NO− to V NO+ .
5. The multi-resistive state element of claim 4 , wherein the conductive element comprises manganite perovskite.
6. The multi-resistive state element of claim 5 , wherein the manganite perovskite is a PCMO.
7. The multi-resistive state element of claim 6 , wherein the reactive metal comprises Al, Ti, Mg, W, Fe, Cr, Vn, Zn, Ta or Mo.
8. The multi-resistive state element of claim 7 , wherein the reactive metal is Al.
9. The multi-resistive state element of claim 7 , comprising 10-100 Angstroms of Al deposited on the PCMO.
10. The multi-resistive state element of claim 9 , comprising 25-50 Angstroms of Al deposited on the PCMO.
11. A memory array comprising a plurality of three-terminal memory elements, wherein each of the three-terminal memory elements comprises:
a multi-resistive state element comprising:
a conductive element,
a reactive metal that reacts with the conductive element, and
an oxygen repository;
wherein the multi-resistive state element is operable to:
change from a high resistive state to a low resistive state upon application of a first write voltage, and
change from a low resistive state to a high resistive state upon application of a second write voltage; and
a transistor coupled with the multi-resistive state element.
12. The memory array of claim 11 , wherein the reactive metal has fully reacted with the conductive element in each of the multi-resistive state elements.
13. The memory array of claim 11 , wherein each multi-resistive state element can be exposed to a range of voltages without disturbing a resistive state of the multi-resistive state element.
14. The memory array of claim 11 , wherein each multi-resistive state element is substantially non-conductive over a range of voltages from V NO− to V NO+ .
15. The memory array of claim 14 , wherein the conductive element comprises manganite perovskite.
16. The memory array of claim 15 , wherein the manganite perovskite is a PCMO.
17. The memory array of claim 16 , wherein the reactive metal comprises Al, Ti, Mg, W, Fe, Cr, Vn, Zn, Ta or Mo.
18. The memory array of claim 17 , wherein the reactive metal is Al.
19. The memory array of claim 17 , comprising 10-100 Angstroms of Al deposited on the PCMO.
20. The memory array of claim 19 , comprising 25-50 Angstroms of Al deposited on the PCMO.