| 1. |
- Miniotas, A, et al.
(författare)
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Large magnetoresistance effect in as-grown epitaxial LaxCa1-xMnO3 films prepared by a molecular beam epitaxy coevaporation technique
- 1998
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 16:3, s. 1268-1271
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Tidskriftsartikel (refereegranskat)abstract
- Thin films of LaxCa1-xMnO3 (0.64 less than or equal to x less than or equal to 0.68) have been grown by NO2-assisted molecular beam epitaxy on single crystal SrTiO3(100) and LaAlO3(100) substrates. As-grown films are found to be grown epitaxially, b-axis oriented on both SrTiO3 and LaAlO3 substrates, and exhibit a large magnetoresistance effect {[R(O)-R(H)]/R(H)X100} of about 1500% at 214 K. The magnetoresistance effect values obtained are similar to those reported for as-grown LaxCa1-xMnO3 (0.60 less than or equal to x less than or equal to 0.7) films synthesized either by so-called "block-by-block" or "layer-by-layer" molecular beam epitaxy techniques, but the effect appears at significantly higher temperatures. For epitaxial La0.68Ca0.32MnO3 films grown on SrTiO3 a relatively large resistance suppression of 200% at 1.0 T is observed. (C) 1998 American Vacuum Society.
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| 2. |
- Miniotas, A, et al.
(författare)
-
Misfit strain induced lattice distortions in heteroepitaxially grown LaxCa1-xMnO3 thin films studied by extended x-ray absorption fine structure and high-resolution x-ray diffraction
- 2001
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 89:4, s. 2134-2137
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Tidskriftsartikel (refereegranskat)abstract
- Mn-O and Mn-Mn interatomic distances were determined in LaxCa1-xMnO3 films grown heteroepitaxially on single crystal SrTiO3 and LaAlO3 substrates by molecular beam epitaxy. Mn-O bond lengths were found to be fixed at similar to1.975 Angstrom for both types of substrates, while the Mn-Mn distance was detected to be larger for films grown on SrTiO3 substrates than for films grown on LaAlO3. The deviation of Mn-Mn interatomic distances, and subsequently Mn-O-Mn bond angles, in epitaxial LaxCa1-xMnO3 films is attributed to the misfit strain: compressive for LaAlO3 and tensile for SrTiO3 substrates. (C) 2001 American Institute of Physics.
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| 3. |
- Miniotas, A., et al.
(författare)
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Gadolinium trihydride - A new magnetoresistive semiconductor
- 2002
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Ingår i: Europhysics letters. - : IOP Publishing. - 0295-5075 .- 1286-4854. ; 58:3, s. 442-447
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Tidskriftsartikel (refereegranskat)abstract
- Large negative magnetoresistance and magnetisation anomalies are found in epitaxial GdH3-delta films. The zero-field semiconductor-like behavior in the resistivity is completely suppressed at a magnetic field of 120 kOe. Temperature and field dependence of the magnetisation supports short-range ordering in the paramagnetic host, mediated by the vacancy state of trihydride.
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| 4. |
- Miniotas, A, et al.
(författare)
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Gigantic resistivity and band gap changes in GdOyHx thin films
- 2000
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Ingår i: APPLIED PHYSICS LETTERS. - : AMER INST PHYSICS. - 0003-6951. ; 76:15, s. 2056-2058
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Tidskriftsartikel (refereegranskat)abstract
- In this letter we show that GdOyHx thin films allow one to tailor the electric and the optical properties by controlling the hydrogen and oxygen content. By changing the O/H ratio, one can shift the optical band gap from 2.4 eV in the trihydride to 5.4 eV
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| 5. |
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