451
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Ramesh R, Inam A, Chan WK, Wilkens B, Myers K, Remschnig K, Hart DL, Tarascon JM. Epitaxial Cuprate Superconductor/Ferroelectric Heterostructures. Science 1991; 252:944-6. [PMID: 17843227 DOI: 10.1126/science.252.5008.944] [Citation(s) in RCA: 199] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Thin-film heterostructures of Bi(4)Ti(3)O(12)Bi(2)Sr(2)CuO(6+x), have been grown on single crystals of SrTiO(3), LaAlO(3), and MgAl(2)O(4) by pulsed laser deposition. X-ray diffraction studies show the presence of c-axis orientation only; Rutherford backscattering experiments show the composition to be close to the nominal stoichiometry. The films are ferroelectric and exhibit a symmetric hysteresis loop. The remanent polarization was 1.0 microcoulomb per square centimeter, and the coercive field was 2.0 x 10(5) volts per centimeter. Similar results were obtained with YBa(2)Cu(3)O(7-x) and Bi(2)Sr(2)CaCu(2)O(8+x), and single-crystal Bi(2)Sr(2)CuO(6+x)as the bottom electrodes. These films look promising for use as novel, lattice-matched, epitaxial ferroelectric film/electrode heterostructures in nonvolatile memory applications.
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452
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Farrow LA, Ramesh R, Tarascon J. Raman spectra of bismuth cuprate high-Tc superconductors and 3d-metal-substituted phases. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 43:418-423. [PMID: 9996227 DOI: 10.1103/physrevb.43.418] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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453
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Ravi TS, Hwang DM, Ramesh R, Chan SW, Nazar L, Chen CY, Inam A, Venkatesan T. Grain boundaries and interfaces in Y-Ba-Cu-O films laser deposited on single-crystal MgO. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 42:10141-10151. [PMID: 9995270 DOI: 10.1103/physrevb.42.10141] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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454
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Tarascon JM, Wang E, Kivelson S, Bagley BG, Hull GW, Ramesh R. Magnetic versus nonmagnetic ion substitution effects on Tc in the La-Sr-Cu-O and Nd-Ce-Cu-O systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 42:218-222. [PMID: 9994529 DOI: 10.1103/physrevb.42.218] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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455
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Li Q, Xi XX, Wu XD, Inam A, Vadlamannati S, McLean WL, Venkatesan T, Ramesh R, Hwang DM, Martinez JA, Nazar L. Interlayer coupling effect in high-Tc superconductors probed by YBa2Cu3O7-x/PrBa2Cu3O7-x superlattices. PHYSICAL REVIEW LETTERS 1990; 64:3086-3089. [PMID: 10041891 DOI: 10.1103/physrevlett.64.3086] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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456
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Ramesh R, Vasudevan R, Kolster BH, Pathiraj B. X-ray evidence for structural transformation in Ni3Al alloys at higher temperatures. Naturwissenschaften 1990. [DOI: 10.1007/bf01134474] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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457
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McKinnon WR, Tselepis E, McAlister SP, Pleizier G, Tarascon JM, Miceli PF, Ramesh R, Hull GW, Waszczak JV, Rhyne JJ, Neumann DA. Structure and magnetism of Bi2(Sr,Ca)2MnO6+y antiferromagnets with ferrimagnetic layers. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 41:4489-4501. [PMID: 9994276 DOI: 10.1103/physrevb.41.4489] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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458
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Sarkar A, Ramesh R, Bhattacharya SK, Rajagopalan G. Oxygen isotope evidence for a stronger winter monsoon current during the last glaciation. Nature 1990. [DOI: 10.1038/343549a0] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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459
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Ramesh R, Hwang DM, Venkatesan T, Ravi TS, Nazar L, Inam A, Wu XD, Dutta B, Thomas G, Marshall AF, Geballe TH. Direct Observation of Structural Defects in Laser-Deposited Superconducting Y-Ba-Cu-O Thin Films. Science 1990; 247:57-9. [PMID: 17749491 DOI: 10.1126/science.247.4938.57] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The defect structure of in situ pulsed, laser-deposited, thin films of the high-transition temperature superconductor Y-Ba-Cu-O has been observed directly by atomic resolution electron microscopy. In a thin film with the nominal composition YBa(2)Cu(3)O(7) (123), stacking defects corresponding to the cationic stoichiometry of the 248, 247, and 224 compounds have been observed. Other defects observed include edge dislocations and antiphase boundaries. These defects, which are related to the nonequilibrium processing conditions, are likely to be responsible for the higher critical currents observed in these films as compared to single crystals.
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460
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Ramesh R, Karwan M, Zionts S. An interactive method for bicriteria integer programming. ACTA ACUST UNITED AC 1990. [DOI: 10.1109/21.52550] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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461
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Sands T, Palmstrøm C, Harbison J, Keramidas V, Tabatabaie N, Cheeks T, Ramesh R, Silberberg Y. Stable and epitaxial metal/III-V semiconductor heterostructures. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/s0920-2307(05)80003-9] [Citation(s) in RCA: 168] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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462
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Siu-Wai Chan, Hwang DM, Ramesh R, Sampere SM, Nazar L, Gerhardt R, Pruna P. Study of YBa2Cu3O7−x thin films grown on single crystal SrTiO3: Not all high angle grain boundaries destroy Jc. ACTA ACUST UNITED AC 1990. [DOI: 10.1063/1.39040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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463
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Sandroff CJ, Harbison JP, Ramesh R, Andrejco MJ, Hegde MS, Chang CC, Vogel EM, Hwang DM. GaAs Clusters in the Quantum Size Regime: Growth on High Surface Area Silica by Molecular Beam Epitaxy. Science 1989; 245:391-3. [PMID: 17744146 DOI: 10.1126/science.245.4916.391] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Molecular beam epitaxy has been used to grow microcrystalline clusters of gallium arsenide (GaAs) in the size range from 2.5 to 60 nanometers on high-purity, amorphous silica supports. High-resolution transmission electron microscopy reveals that clusters as small as 3.5 nanometers have good crystalline order with a lattice constant equal to that of bulk GaAs. Study of the microcrystallite surfaces by x-ray photoelectron spectroscopy shows that they are covered with a shell (1.0 to 1.5 nanometers thick) of native oxides of gallium and arsenic (Ga(2)O(3) and As(2)O(3)), whose presence could explain the low luminescence efficiency of the clusters. Optical absorption spectra of the supported GaAs are consistent with the blue-shifted band edge expected for semiconductor microcrystallites in the quantum size regime.
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464
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Koestler C, Ramesh R, Echer C, Thomas G, Wecker J. Microstructure of melt spun Nd-FeCoB magnets. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0001-6160(89)90079-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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465
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Tarascon J, Barboux P, Hull GW, Ramesh R, Greene LH, Giroud M, Hegde MS, McKinnon WR. Bismuth cuprate high-Tc superconductors using cationic substitution. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 39:4316-4326. [PMID: 9948772 DOI: 10.1103/physrevb.39.4316] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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466
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Ramesh R, Thomas G, Green S, Jiang C, Mei Y, Rudee ML, Luo HL. Polytypoid structure of Pb-modified Bi-Ca-Sr-Cu-O superconductor. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:7070-7073. [PMID: 9945402 DOI: 10.1103/physrevb.38.7070] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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467
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Chandrasekaran G, Ramesh R. Microcomputer based multiple criteria decision support system for strategic planning. INFORMATION & MANAGEMENT 1987. [DOI: 10.1016/0378-7206(87)90039-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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468
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Ramesh R, Drury CG. EARS: An online bibliographic search and retrieval system based on ordered explosion. Inf Process Manag 1987. [DOI: 10.1016/0306-4573(87)90006-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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469
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Ramesh R, Patel CK, Patel RD. Cellulose-Einkristalle. Colloid Polym Sci 1975. [DOI: 10.1007/bf02352177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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