Antiferromagnetic memory storage devices from magnetic transition metal dichalcogenides
Switchable antiferromagnetic (AFM) memory devices are provided based on magnetically intercalated transition metal dichalcogenides (TMDs) of the form A x MC 2 , where A is a magnetic element of stoichiometry x between 0 and 1, M is a transition metal of stoichiometry 1, and C is a chalcogen of stoichiometry 2. Memory storage is achieved by fabricating these materials into crosses of two or more bars and driving DC current pulses along the bars to rotate the AFM order to a fixed angle with respect to the current pulse. Application of current pulses along different bars can switch the AFM order between multiple directions. Standard resistance measurements can detect the orientation of the AFM order as high or low resistance states. The state of the device can be set by the input current pulses, and read-out by the resistance measurement, forming a non-volatile, AFM memory storage bit.
1. An antiferromagnetic composition, comprising:
(a) a magnetically intercalated transition metal dichalcogenide material of a formula A x MC 2 in a 2H crystalline phase;
(b) wherein each A is at least one magnetic transition metal intercalant of stoichiometry x ranging from 0 to 1;
(c) wherein each M is a transition metal with a stoichiometry 1; and
(d) wherein each C is a chalcogen with a stoichiometry of 2.
2. The composition of claim 1 , wherein the magnetic transition metal intercalant is selected from the group of metals consisting of iron (Fe), nickel (Ni), chromium (Cr) cobalt (Co), manganese (Mn) and vanadium (V).
3. The composition of claim 1 , wherein the magnetic transition metal intercalant is two metals selected from the group of metals consisting of iron (Fe), nickel (Ni), chromium (Cr), cobalt (Co), manganese (Mn) and vanadium (V).
4. The composition of claim 1 , wherein stoichiometry of the magnetic transition metal intercalant is in the range of 0.30 to 0.36.
5. The composition of claim 1 , wherein stoichiometry of the magnetic transition metal intercalant is in the range of 0.32 to 0.34.
6. The composition of claim 1 , wherein stoichiometry of the magnetic transition metal intercalant is about 0.31.
7. The composition of claim 3 , wherein stoichiometry of the two magnetic transition metal intercalants is in the range of 0.05 to 0.33.
8. The composition of claim 1 , wherein the transition metal (M) is a metal selected from the group of metals consisting of niobium (Nb), molybdenum (Mo), tantalum (Ta) and tungsten (W).
9. The composition of claim 1 , wherein the chalcogen (C) is selected from the group consisting of sulfur (S), selenium (Se), and tellurium (Te).
10. An electrically switchable antiferromagnetic device, the device comprising:
(a) a device body of a magnetically intercalated transition metal dichalcogenide material of a formula Ai x MC 2 in a 2H crystalline phase;
wherein each A is at least one magnetic transition metal intercalant of stoichiometry x ranging from 0 to 1;
(ii) wherein each M is a transition metal with a stoichiometry 1; and
(iii) wherein each C is a chalcogen with a stoichiometry of 2;
(b) said body with at least one write-in electrode electrically coupled to a source of current; and
(c) said body with at least one read out electrode configured to measure resistance;
(d) wherein an antiferromagnetic order of said device body rotates with the application of current to said write in electrode from said current source.
11. The device of claim 10 , wherein the magnetic transition metal intercalant is selected from the group of metals consisting of iron (Fe), nickel (Ni), chromium (Cr) cobalt (Co), manganese (Mn) and vanadium (V).
12. The device of claim 10 , wherein the magnetic transition metal intercalant is two metals selected from the group of metals consisting of iron (Fe), nickel (Ni), chromium (Cr) cobalt (Co), manganese (Mn) and vanadium (V).
13. The device of claim 10 , wherein stoichiometry of the magnetic transition metal intercalant is in the range of 0.30 to 0.36.
14. The device of claim 10 , wherein the transition metal (M) is a metal selected from the group of metals consisting of niobium (Nb), molybdenum (Mo), tantalum (Ta) and tungsten (W).
15. The device of claim 10 , wherein the chalcogen (C) is selected from the group consisting of sulfur (S), selenium (Se), and tellurium (Te).
16. A method of manipulating antiferromagnetic ordering in an antiferromagnetic material, the method comprising:
(a) forming an active element of a magnetically intercalated transition metal dichalcogenide material of a formula Ai x MC 2 in a 2H crystalline phase;
(i) wherein each A is at least one magnetic transition metal intercalant of stoichiometry x ranging from 0 to 1;
(ii) wherein each M is a transition metal with a stoichiometry 1; and
(iii) wherein each C is a chalcogen with a stoichiometry of 2;
(b) forming a plurality of write-in electrodes in said active element, said electrodes electrically coupled to a source of current;
(c) forming a plurality of read-out electrodes in said active element, said electrodes;
(d) applying a current pulse to one write-in electrode; and
(e) measuring a resistance of at least one read-out electrode to determine a resistance state.
17. The method of claim 16 , further comprising:
applying a second current pulse to an electrode in an orthogonal orientation to the first current pulse electrode;
measuring a resistance of at least one read-out electrode; and
assigning a resistance state from the measured resistance after the second current pulse.
18. The method of claim 16 , wherein the magnetic transition metal intercalant is selected from the group of metals consisting of iron (Fe), nickel (Ni), chromium (Cr) cobalt (Co), manganese (Mn) and vanadium (V).
19. The method of claim 16 , wherein said transition metal (M) is a metal selected from the group of metals consisting of niobium (Nb), molybdenum (Mo), tantalum (Ta) and tungsten (W).
20. The method of claim 16 , wherein the chalcogen (C) is selected from the group consisting of sulfur (S), selenium (Se), and tellurium (Te).