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Philip J, Punnoose A, Kim BI, Reddy KM, Layne S, Holmes JO, Satpati B, Leclair PR, Santos TS, Moodera JS. Carrier-controlled ferromagnetism in transparent oxide semiconductors. NATURE MATERIALS 2006; 5:298-304. [PMID: 16547517 DOI: 10.1038/nmat1613] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Accepted: 01/24/2006] [Indexed: 05/07/2023]
Abstract
The search for an ideal magnetic semiconductor with tunable ferromagnetic behaviour over a wide range of doping or by electrical gating is being actively pursued as a major step towards realizing spin electronics. A magnetic semiconductor having a high Curie temperature, capable of independently controlled carrier density and magnetic doping, is crucial for developing spin-based multifunctional devices. Cr-doped In(2)O(3) is such a unique system, where the electrical and magnetic behaviour-from ferromagnetic metal-like to ferromagnetic semiconducting to paramagnetic insulator-can be controllably tuned by the defect concentration. An explicit dependence of magnetic interaction leading to ferromagnetism on the carrier density is shown. A carrier-density-dependent high Curie temperature of 850-930 K has been measured, in addition to the observation of clear magnetic domain structures in these films. Being optically transparent with the above optimal properties, Cr-doped In(2)O(3) emerges as a viable candidate for the development of spin electronics.
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LeClair P, Moodera JS, Philip J, Heiman D. Coexistence of ferromagnetism and superconductivity in Ni/Bi bilayers. PHYSICAL REVIEW LETTERS 2005; 94:037006. [PMID: 15698312 DOI: 10.1103/physrevlett.94.037006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Indexed: 05/24/2023]
Abstract
In spite of a lack of superconductivity in bulk crystalline Bi, thin film Bi deposited on thin Ni underlayers are strong-coupled superconductors below approximately 4 K. We unambiguously demonstrate that by tuning the Ni thickness the competition between ferromagnetism and superconductivity in the Ni/Bi can be tailored. For a narrow range of Ni thicknesses, the coexistence of both a superconducting energy gap and conduction electron spin polarization are visible within the Ni side of the Ni/Bi bilayers, independent of any particular theoretical model. We believe that this represents one of the clearest observations of superconductivity and ferromagnetism coexisting.
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LeClair P, Kohlhepp JT, van De Vin CH, Wieldraaijer H, Swagten HJM, de Jonge WJM, Davis AH, MacLaren JM, Moodera JS, Jansen R. Band structure and density of States effects in co-based magnetic tunnel junctions. PHYSICAL REVIEW LETTERS 2002; 88:107201. [PMID: 11909383 DOI: 10.1103/physrevlett.88.107201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2001] [Indexed: 05/23/2023]
Abstract
Utilizing Co/Al(2)O(3)/Co magnetic tunnel junctions with Co electrodes of different crystalline phases, a clear relationship between electrode crystal structure and junction transport properties is presented. For junctions with one fcc(111) textured and one polycrystalline (polyphase and polydirectional) Co electrode, a strong asymmetry is observed in the magnetotransport properties, while when both electrodes are polycrystalline the magnetotransport is essentially symmetric. These observations are successfully explained within a model based on ballistic tunneling between the calculated band structures (density of states) of fcc-Co and hcp-Co.
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Byers JM, Osofsky MS, Nadgorny B, Ambrose T, Cheng SF, Nowak J, Moodera JS, Barry A, Coey JMD. Measuring the spin polarization of a metal with a superconducting point contact. Science 1998; 282:85-8. [PMID: 9756482 DOI: 10.1126/science.282.5386.85] [Citation(s) in RCA: 1474] [Impact Index Per Article: 56.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A superconducting point contact is used to determine the spin polarization at the Fermi energy of several metals. Because the process of supercurrent conversion at a superconductor-metal interface (Andreev reflection) is limited by the minority spin population near the Fermi surface, the differential conductance of the point contact can reveal the spin polarization of the metal. This technique has been applied to a variety of metals where the spin polarization ranges from 35 to 90 percent: Ni0.8Fe0.2, Ni, Co, Fe, NiMnSb, La0.7Sr0.3MnO3, and CrO2.
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Moodera JS, Kinder LR, Wong TM, Meservey R. Large magnetoresistance at room temperature in ferromagnetic thin film tunnel junctions. PHYSICAL REVIEW LETTERS 1995; 74:3273-3276. [PMID: 10058155 DOI: 10.1103/physrevlett.74.3273] [Citation(s) in RCA: 393] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
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58
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Nguyen PP, Wang Z, Rao AM, Dresselhaus MS, Moodera JS, Dresselhaus G, Radousky HB, Glass RS, Liu JZ. Transport and magnetic properties of YBa2Cu3O7- delta Bry single crystals. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:1148-1155. [PMID: 10007975 DOI: 10.1103/physrevb.48.1148] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Moodera JS, Meservey R, Hao X. Variation of the electron-spin polarization in EuSe tunnel junctions from zero to near 100% in a magnetic field. PHYSICAL REVIEW LETTERS 1993; 70:853-856. [PMID: 10054220 DOI: 10.1103/physrevlett.70.853] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Moodera JS, Meservey R. Reply to "Comment on 'Superconducting phases of Bi and Ga induced by deposition on a Ni sublayer' ". PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 47:550-551. [PMID: 10004487 DOI: 10.1103/physrevb.47.550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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61
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Wang Y, Rao AM, Zhang J, Bi X, Eklund PC, Dresselhaus MS, Nguyen PP, Moodera JS, Dresselhaus G, Radousky HB, Glass RS, Fluss MJ, Liu JZ. ab-plane optical properties of YBa2Cu3O7- delta Bry single crystals. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 45:2523-2526. [PMID: 10001786 DOI: 10.1103/physrevb.45.2523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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62
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Hao X, Moodera JS, Meservey R. Thin-film superconductor in an exchange field. PHYSICAL REVIEW LETTERS 1991; 67:1342-1345. [PMID: 10044121 DOI: 10.1103/physrevlett.67.1342] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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63
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Hao X, Moodera JS, Meservey R. Spin-filter effect of ferromagnetic europium sulfide tunnel barriers. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 42:8235-8243. [PMID: 9994996 DOI: 10.1103/physrevb.42.8235] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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64
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Moodera JS, Meservey R. Superconducting phases of Bi and Ga induced by deposition on a Ni sublayer. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 42:179-183. [PMID: 9994523 DOI: 10.1103/physrevb.42.179] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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65
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Brorson SD, Kazeroonian A, Moodera JS, Face DW, Cheng TK, Ippen EP, Dresselhaus MS, Dresselhaus G. Femtosecond room-temperature measurement of the electron-phonon coupling constant gamma in metallic superconductors. PHYSICAL REVIEW LETTERS 1990; 64:2172-2175. [PMID: 10041602 DOI: 10.1103/physrevlett.64.2172] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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66
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Kussmaul A, Moodera JS, Roesler GM, Tedrow PM. Quasiparticle tunneling in Bi-Sr-Ca-Cu-O thin films. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 41:842-845. [PMID: 9992838 DOI: 10.1103/physrevb.41.842] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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67
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Moodera JS, Taylor ME, Meservey R. Exchange-induced spin polarization of conduction electrons in paramagnetic metals. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:11980-11982. [PMID: 9991817 DOI: 10.1103/physrevb.40.11980] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Moodera JS, Meservey R. Exchange interactions of quench-condensed vanadium atoms on metal surfaces. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:8541-8544. [PMID: 9991323 DOI: 10.1103/physrevb.40.8541] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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69
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Moodera JS, Hao X, Gibson GA, Meservey R. Electron-spin polarization in tunnel junctions in zero applied field with ferromagnetic EuS barriers. PHYSICAL REVIEW LETTERS 1988; 61:637-640. [PMID: 10039387 DOI: 10.1103/physrevlett.61.637] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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70
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Moodera JS, Meservey R, Tkaczyk JE, Hao CX, Gibson GA, Tedrow PM. Critical-magnetic-field anisotropy in single-crystal YBa2Cu3O7. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 37:619-622. [PMID: 9943634 DOI: 10.1103/physrevb.37.619] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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71
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Moodera JS, Tedrow PM, Tkaczyk JE. High-magnetic-field study of superconducting YBa2Cu. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 36:8329-8332. [PMID: 9942647 DOI: 10.1103/physrevb.36.8329] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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72
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Stankowski J, Kahol PK, Dalal NS, Moodera JS. Possible Josephson oscillations spectra and electron paramagnetic resonance of Cu2+ in Y-Ba-Cu-O. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 36:7126-7128. [PMID: 9942441 DOI: 10.1103/physrevb.36.7126] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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73
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Moodera JS, Meservey R. Magnetic properties of transition-metal atoms and thin layers deposited on nonmagnetic metals. PHYSICAL REVIEW. B, CONDENSED MATTER 1986; 34:379-386. [PMID: 9939272 DOI: 10.1103/physrevb.34.379] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Moodera JS, Meservey R. Detection of magnetic moments of Ni and Fe atoms on the surface of Pb. PHYSICAL REVIEW LETTERS 1985; 55:2082-2085. [PMID: 10032005 DOI: 10.1103/physrevlett.55.2082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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