| 1. |
|
|
| 2. |
- Andersson, Jon Martin, et al.
(författare)
-
Phase control of Al2O3 thin films grown at low temperatures
- 2006
-
Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 513:1-2, s. 57-59
-
Tidskriftsartikel (refereegranskat)abstract
- Low-temperature growth (500 °C) of α-Al2O3 thin films by reactive magnetron sputtering was achieved for the first time. The films were grown onto Cr2O3 nucleation layers and the effects of the total and O2 partial pressures were investigated. At 0.33 Pa total pressure and ≥ 16 mPa O2 partial pressure α-Al2O3 films formed, while at lower O2 pressure or higher total pressure (0.67 Pa), only γ phase was detected in the films (which were all stoichiometric). Based on these results we suggest that α phase formation was promoted by a high energetic bombardment of the growth surface. This implies that the phase content of Al2O3 films can be controlled by controlling the energy of the depositing species. The effect of residual H2O (10− 4 Pa) on the films was also studied, showing no change in phase content and no incorporated H (< 0.1%). Overall, these results are of fundamental importance in the further development of low-temperature Al2O3 growth processes.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Hugosson, Håkan Wilhelm, 1972-, et al.
(författare)
-
Stabilization of potential superhard RuO2 phases: A theoretical study
- 2002
-
Ingår i: Physical Review B Condensed Matter. - : American Physical Society. - 0163-1829 .- 1095-3795. ; 66:17
-
Tidskriftsartikel (refereegranskat)abstract
- First-principles full-potential linear muffin-tin orbital calculations have been used to study RuO2 in the fluorite (CaF2) and rutile structures. An investigation of the effects of metal and nonmetal alloying, oxygen vacancies, and lattice strain on the phase stabilities and electronic structure has been made. From these theoretical results suggestions on how the cubic phase may be stabilized are made. The pressure induced phase transitions between the rutile, CaCl2, Pa3 and fluorite phases and the bulk moduli of several 4d and 5d transition metal dioxides have also been studied.
|
|
| 7. |
- Jacobsen, SN, et al.
(författare)
-
Sharp microfaceting of (001)-oriented cerium dioxide thin films and the effect of annealing on surface morphology
- 1999
-
Ingår i: Surface Science. - 0039-6028. ; 429:1-3, s. 22-33
-
Tidskriftsartikel (refereegranskat)abstract
- Cerium dioxide, CeO2, is a chemically stable oxygen-ion-conducting material, which has been extensively used as an additive or support in oxidation catalysts. The fact that catalytic behaviour is often surface structure sensitive and/or edge atom dependent suggests that different surfaces might be discernible in associated redox processes. Thus, it is desirable to realise CeO2 films with a well-defined microstructure and with crystallographically uniform surfaces. In this paper we present evidence of extremely sharp microfaceting on the surface of thin CeO2 films grown by r.f. magnetron sputtering, and the effect of annealing on the formed sharp ridges. The results show that nominally designated crystallographic surfaces may in fact not coincide with the surfaces exposed as-grown. Thus, there is a clear risk for erroneous interpretation of various orientation-dependent surface properties. Carefully controlled annealing of these films can be utilised as a method for tailoring the resulting surface morphology on the atomic scale.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- MAGNUSSON, J, et al.
(författare)
-
FLUX PINNING IN YBA2CU3O7 THIN-FILMS GROWN BY DC MAGNETRON SPUTTERING
- 1992
-
Ingår i: Cryogenics (Guildford). - : Elsevier BV. - 0011-2275 .- 1879-2235. ; 32, s. 1084-1088
-
Tidskriftsartikel (refereegranskat)abstract
- Thin films of YBa2Cu3O7 (YBCO) were deposited on single crystalline LaAlO3 substrates using d.c. magnetron sputtering. The quality of the films has been assessed by X-ray diffraction; YBa2Cu3O7 grows epitaxially with the c-axis parallel to the substrate normal. For some choices of the deposition parameters in the sputtering process, it was found that secondary phases were precipitated in the films. By a deliberate choice of deposition parameters, semi-coherently grown Y2O3 (yttria) inclusions could be obtained. They had square platelet or cubical shapes with sizes from 5 - 20 nm and thickness approximately 10 nm. The superconducting properties of the YBa2Cu3O7 films were investigated using SQUID magnetometry. Magnetization measurements on films with different densities of semicoherent Y2O3 inclusions indicate an enhanced flux pinning capability with increasing inclusion density.
|
|
