| 1. |
- Aggarwal, MM, et al.
(författare)
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Centrality dependence of charged-neutral particle fluctuations in 158A (GeVPb)-Pb-208+Pb-208 collisions
- 2003
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 67:4
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Tidskriftsartikel (refereegranskat)abstract
- Results on the study of localized fluctuations in the multiplicity of charged particles and photons produced in 158A GeV/c Pb+Pb collisions are presented for varying centralities. The charged versus neutral particle multiplicity correlations in common phase space regions of varying azimuthal sizes are analyzed by two different methods. Various types of mixed events are constructed to probe fluctuations arising from different sources. The measured results are compared to those from simulations and from mixed events. The comparison indicates the presence of nonstatistical fluctuations in both the charged particle and photon multiplicities in limited azimuthal regions. However, no correlated charged-neutral fluctuations, a possible signature of formation of disoriented chiral condensates, are observed. An upper limit on the production of disoriented chiral condensates is set.
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| 2. |
- Georg, U., et al.
(författare)
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Isotope production comparison at ISOLDE with 1 and 1.4 GeV protons
- 2002
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Ingår i: Nuclear Physics A. - 0375-9474. ; 701, s. 137C-143C
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Konferensbidrag (refereegranskat)abstract
- The difference in isotope production between 1 and 1.4 GeV proton projectiles was investigated at ISOLDE/CERN during the year 1999. As target materials uranium carbide, thorium carbide, lead and lanthanum oxide were used and the ratio of the measured production yields for the two different projectile energies were determined for isotopes of the elements francium, mercury, thallium, xenon, cesium, krypton, rubidium and neon. A comparison of these experimental results with the predictions from a two-step reaction model Monte-Carlo code shows good agreement. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 3. |
- Konofaos, N., et al.
(författare)
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Electrical characterisation of SrTiO3/Si interfaces
- 2002
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Ingår i: Journal of Non-Crystalline Solids. - 0022-3093 .- 1873-4812. ; 303:1, s. 185-189
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Tidskriftsartikel (refereegranskat)abstract
- Deposition of SrTiO3 (STO) thin films by ultra-high vacuum rf magnetron sputtering was performed in order to produce high-quality STO/p-Si (1 0 0) interfaces and STO insulator layers with high dielectric constants. The deposition temperatures were in the range from room temperature to 550 °C. Capacitance-voltage (C-V) and conductance-frequency measurements showed that the dielectric constant of the films ranges from 55 to 120. C-V measurements on Al/STO/p-Si structures clearly revealed the creation of metal-insulator-semiconductor diodes. The interface state densities (Dit) at the STO/p-Si interfaces were obtained from admittance spectroscopy measurements. The samples deposited at lower temperatures revealed values of Dit between 2 × 1011 and 3.5 × 1012 eV-1 cm-2 while the higher temperature deposited samples had a higher Dit ranging between 1 × 1011 and 1 × 1013 eV-1 cm-2. The above results were also well correlated to X-ray diffraction measurements, Rutherford backscattering spectroscopy, and spectroscopic ellipsometry. © 2002 Elsevier Science Ltd. All rights reserved.
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| 4. |
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| 5. |
- Wang, Z., et al.
(författare)
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Characteristics of SrTiO3 thin films deposited on Si by rf magnetron sputtering at various substrate temperatures
- 2002
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Ingår i: Philosophical Magazine B. - : Informa UK Limited. - 1364-2812 .- 1463-6417. ; 82:8, s. 891-903
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Tidskriftsartikel (refereegranskat)abstract
- SrTiO3 (STO) thin films were deposited on p-type Si(100) substrates by rf magnetron sputtering at various substrate temperatures, and their structural and electrical properties were investigated without post-deposition annealing. The thickness of the films was in the range from 300 to 500 nm while the deposition temperature was varied between room temperature and 550°C. Compositional and structural characterizations included X-ray diffraction, Rutherford back-scattering spectroscopy and variable-angle spectroscopic ellipsometry. Metal-insulator-semiconductor diodes with the configuration of Al/STO/p-Si/Al were fabricated and characterized by capacitance-voltage, current voltage and admittance spectroscopy measurements. Depending on the substrate temperatures, the dielectric constant of the films varied between 60 and 120 and the loss factor between 0.019 and 0.051 at 100 kHz. All films showed high charge storage capacity, varying between 1.9 and 3 µm cm-2. However, the films deposited at 200°C showed the lowest density of bulk trapped charges (150nC cm-2) and interface states ((1.2-6.1) × 1011 cm-2 eV-1), and are therefore considered to be the most suitable for device applications.
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| 6. |
- Wang, Z., et al.
(författare)
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Electrical properties of SrTiO3 thin films on Si deposited by magnetron sputtering at low temperature
- 2001
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 79:10, s. 1513-1515
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Tidskriftsartikel (refereegranskat)abstract
- Deposition of SrTiO3 (STO) thin films by radio-frequency magnetron sputtering in an ultrahigh vacuum system at a low substrate temperature (~200°C) was performed in order to produce high-quality STO/p-Si (100) interfaces and STO insulator layers with dielectric constants of high magnitude. The STO films were identified as polycrystalline by x-ray diffraction, and were approximated with a layered structure according to the best fitting results of raw data from both Rutherford backscattering spectroscopy and variable angle spectroscopic ellipsometry. Room-temperature current-voltage and capacitance-voltage (C-V) measurements on Al/STO/p-Si diodes clearly revealed metal-insulator-semiconductor behavior, and the STO/p-Si interface state densities were of the order of 1011 eV-1 cm-2. The dielectric constant of the STO film was 65, and the dielectric loss factor varied between 0.05 and 0.55 for a frequency range of 1 kHz-10 MHz. For a 387 nm thick STO film, the dielectric breakdown field was 0.31 MV cm-1, and the charge storage capacity was 2.1 µC cm-2. These results indicate that STO films are suitable for applications as insulator layers in dynamic random access memories or as cladding layers in electroluminescent devices. © 2001 American Institute of Physics.
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