Magnetically-and electrically-induced variable resistance materials and method for preparing same
View Patent ↗Provided are new compositions of ruthenates in the pervoskite and layered pervoskite family, wherein the ruthenate compositions exhibit large magnetoresistance (MR) and electric-pulse-induced resistance (EPIR) switching effects, the latter observable at room temperature. This is the first time large MR and EPIR effects have been shown together in ruthenate compositions. Further provided are methods for synthesizing the class of ruthenates that exhibits such properties, as well as methods of use therefor in electromagnetic devices, thin films, sensors, semiconductors, insulators and the like.
1. A switching device comprising:
a magnetoresistive material formed from a ruthenate formulation of a perovskite family of materials; and
plurality of contact points;
wherein said magnetoresistive material exhibits an electric-pulse-induced resistance (EPIR) switching effect;
wherein said ruthenate formulation comprises an oxide formulation represented by A(Ru 1−x M x )O 3 , where 0.01<x<0.5; M is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co and Ni, as well as any mixture thereof; and A is selected from the group consisting of K, Ca, Sr, Ba, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Y, as well as any mixture thereof;
wherein elements selected from the group consisting of Sc, Y, Zr, Nb, Hf, Ta, Al, Ga, Ge and Sn are incorporated into M in minority to vary the magnitude of electrical resistance.
2. A switching device comprising:
a magnetoresistive material formed from a ruthenate formulation of a perovskite family of materials; and
plurality of contact points;
wherein said magnetoresistive material exhibits an electric-pulse-induced resistance (EPIR) switching effect;
wherein said ruthenate formulation comprises an oxide formulation of (Sr 0.7 La 0.3 )(Ru 0.7 Fe 0.3 )O 3 or (Sr 0.8 La 0.2 )(Ru 0.8 Fe 0.2 )O 3 .
3. The device of claim 2 , wherein Fe is replaced by Co.
4. The device of claim 2 , wherein Sr is replaced by Ca.
5. A switching device comprising:
a magnetoresistive material formed from a ruthenate formulation of a perovskite family of materials; and
plurality of contact points;
wherein said magnetoresistive material exhibits an electric-pulse-induced resistance (EPIR) switching effect;
wherein said ruthenate formulation further comprises a spin glass formulation represented A n+1 (Ru 1−x M x ) n O 3n+1 , where n is any positive integer, 0.01<x<0.5, M is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co and Ni, as well as any mixture thereof; and A is selected from the group consisting of K, Ca, Sr, Ba, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Y, as well as any mixture thereof;
wherein elements selected from the group consisting of Sc, Y, Zr, Nb, Hf, Ta, Al, Ga, Ge and Sn are incorporated into M in minority to vary the magnitude of electrical resistance.
6. A switching device comprising:
a magnetoresistive material formed from a ruthenate formulation of a perovskite family of materials; and
plurality of contact points;
wherein said magnetoresistive material exhibits an electric-pulse-induced resistance (EPIR) switching effect;
wherein said ruthenate formulation further comprises a spin glass formulation comprising Sr 1.8 La 0.2 Ru 0.8 Fe 0.2 O 4 .
7. The device of claim 6 , wherein Fe is replaced by Co.
8. The device of claim 6 , wherein Sr is replaced by Ca.
9. A method for performing electric-pulse-induced resistance (EPIR) switching comprising:
depositing a magnetoresistive material formed from a ruthenate formulation of a perovskite family of material on a substrate, wherein said magnetoresistive material exhibits an electric-pulse-induced resistance (EPIR) switching effect; and
creating an electric-pulse-induced resistance switching effect by applying a field to said electrical contacts.
10. The method as set forth in claim 9 , wherein said magnetoresistive material has a magnetoresistance (MR) effect of about 18% or more.
11. The method as set forth in claim 9 , wherein said EPIR switching effect occurs at room temperature.
12. The method of claim 9 , wherein said ruthenate formulation comprises an oxide formulation represented by A(Ru 1−x M x )O 3 , where 0.01<x<0.5, M is selected from the group consisting of magnetic elements; A is selected from the group consisting of K, Ca, Sr, Ba, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Y, as well as any mixture thereof.
13. The method of claim 12 , wherein the magnetic elements M are selected from the group consisting of Ti, V, Cr, Mn, Fe, Co and Ni, as well as any mixture thereof.
14. The method of claim 13 , wherein elements selected from the group consisting of Sc, Y, Zr, Nb, Hf, Ta, Al, Ga, Ge and Sn are incorporated into M in minority to vary the magnitude of electrical resistance.
15. The method of claim 13 , wherein M is further selected from the group consisting of Cr, Mn, Fe, Co and Ni.
16. The method of claim 15 , wherein M is further selected from Fe or Co.
17. The method of claim 16 , wherein said oxide formulation is (Sr 0.7 La 0.3 )(Ru 0.7 Fe 0.3 )O 3 or (Sr 0.8 La 0.2 )(Ru 0.8 Fe 0.2 )O 3 .
18. The method of claim 17 , wherein Fe is replaced by Co.
19. The method of claim 17 , wherein Sr is replaced by Ca.
20. The method of claim 9 , wherein said ruthenate formulation further comprises a spin glass formulation represented A n+1 (RU 1−x M x ) n O 3n+1 , where n is any positive integer, 0.01<x<0.5, M is selected from the group consisting of magnetic elements; A is selected from the group consisting of K, Ca, Sr, Ba, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Y, as well as any mixture thereof.
21. The method of claim 20 , wherein said ruthenate formulation is represented by A 2 (Ru 1−x M x )O 4 .
22. The method of claim 20 , wherein the magnetic elements M are selected from the group consisting of Ti, V, Cr, Mn, Fe, Co and Ni, as well as any mixture thereof.
23. The method of claim 22 , wherein elements selected from the group consisting of Sc, Y, Zr, Nb, Hf, Ta, Al, Ga, Ge and Sn are incorporated into M in minority to vary the magnitude of electrical resistance.
24. The method of claim 22 , wherein M is further selected from the group consisting of Cr, Mn, Fe, Co and Ni.
25. The method of claim 24 , wherein M is further selected from Fe or Co.
26. The method of claim 25 , wherein said ruthenate is Sr 1.8 La 0.2 Ru 0.8 Fe 0.2 O 4 .
27. The method of claim 26 , wherein Fe is replaced by Co.
28. The method of claim 26 , wherein Sr is replaced by Ca.