| 1. |
- Batlle, X., et al.
(author)
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Quantitative x-ray photoelectron spectroscopy study of Al/AlOx bilayers
- 2002
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In: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 91:12, s. 10163-10168
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Journal article (peer-reviewed)abstract
- An x-ray photoelectron spectroscopy (XPS) analysis of Nb/Al wedge bilayers, oxidized by both plasma and natural oxidation, is reported. The main goal is to show that the oxidation state-i.e., O:(oxidize)Al ratio-, structure and thickness of the surface oxide layer, as well as the thickness of the metallic Al leftover, as functions of the oxidation procedure, can be quantitatively evaluated from the XPS spectra. This is relevant to the detailed characterization of the insulating barriers in (magnetic) tunnel junctions.
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| 2. |
- Batlle, X., et al.
(author)
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The oxidation state at tunnel junction interfaces
- 2003
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In: Journal of Magnetism and Magnetic Materials. - 0304-8853 .- 1873-4766. ; 260:02-jan, s. 78-83
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Journal article (peer-reviewed)abstract
- The oxidation state at the interfaces of Nb/Al-AlOx/Pb junctions is discussed. Conductance-voltage curves below and above the superconducting temperature suggest tunneling conduction, while X-ray photoelectron spectroscopy shows the existence of a thin AlOx layer at the Nb/Al interface. We demonstrate that at the usual 10(-7) Torr range of base pressures in the sputtering chamber, this is due to the time elapsed between the deposition of the Nb and Al bottom layers, in both Nb/Al-AlOx/Pb tunnel junctions and Nb/Al bilayers. We also give some direct evidence of the oxidation of the top Pb electrode on the Nb electrode surface. Such oxidation probably occurs at the pinholes of the intermediate Al-AlOx layer of the tunnel junctions, as a consequence of the oxidation state at the Nb/Al interface, which helps to avoid barrier shorts and enhances the quality of the tunnel barrier. We therefore suggest that there is oxide formation in other places besides where there is an actual oxide deposited. This is relevant for the performance of magnetic tunnel junctions since in most tunneling studies it is assumed that once the oxide is deposited, that is the only place where there is an oxide. This is also a very general statement applicable to thin film systems.
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| 3. |
- Candinas, R, et al.
(author)
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Impact of fusion avoidance on performance of the automatic threshold tracking feature in dual chamber pacemakers: A multicenter prospective randomized study
- 2002
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In: PACE. - : Wiley. - 1540-8159. ; 25:11, s. 1540-1545
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Journal article (peer-reviewed)abstract
- The Autocapture algorithm enables automatic capture verification on a beat-by-beat basis by recognizing the evoked response signal following each pacemaker stimulus. The algorithm intends to increase patient safety while decreasing energy consumption. However, the occurrence of fusion beats, particularly during dual chamber pacing, may limit the energy saving effect of Autocapture. The aim of this multicenter, prospective, randomized study was to evaluate the impact of the Fusion Avoidance (FA) algorithm on the incidence of fusion beats. Thirty-eight patients (mean age 69 +/- 13 years) with intrinsic AV conduction who were implanted with an Affinity DR were studied. After programming a PV/AV delay of 120/190 ms, patients were randomized to FA On or Off. Each group was further randomized with respect to activation of the AutoIntrinsic Conduction Search (AICS) algorithm. The total number of beats, ventricular paced beats, fusion beats, backup pulses, and threshold searches were analyzed from 24-hour Holter recordings. The number of total beats was comparable in both FA groups. The number of total ventricular paced beats, fusion beats, backup pulses, and threshold searches were significantly reduced in the FA On group (% reduction: 68% P < 0.001, 75% P < 0.01, 95% P < 0.01, and 94% P < 0.05, respectively). The number of ventricular paced beats with full capture was significantly reduced when AICS was activated (P < 0.05). In conclusion, the FA algorithm substantially reduces the amount of ventricular paced beats, fusion beats, unnecessary backup pulses and threshold searches, and therefore, provides added benefits in energy saving obtained by Autocapture.
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| 6. |
- Ryden, L, et al.
(author)
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Arne Larsson 1915-2001 - Obituary
- 2002
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In: PACE. - : Wiley. - 1540-8159 .- 0147-8389. ; 25:4, s. 521-521
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Journal article (other academic/artistic)
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