| 1. |
|
|
| 2. |
|
|
| 3. |
- Dahbi, Mohammed, et al.
(författare)
-
Electrochemical behavior of LiNi1-y-zCoyMnzO2 probed through structural and magnetic properties
- 2012
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 111:2, s. 023904-
-
Tidskriftsartikel (refereegranskat)abstract
- We have investigated LixNi1-y-zCoyMnzO2 compounds with y = 1/3, 0.25, 0.2, 0.1 and z = 1/3, 0.2, 0.1, 0.05 in order to study the influence of Ni and Mn concentration, cationic disorder, and crystallite size on the magnetic and charge/discharge behavior. The samples have been studied by means of x-ray diffraction, scanning electron microscopy, voltammetry, cycling capacity, and magnetometry. The discharge capacity increases with increasing Ni concentration as does the number of ferromagnetic interactions. With higher Mn concentration a higher capacity is observed together with formation of strong antiferromagnetic interactions driving the magnetic frustration to lower temperatures. Our results show that for sufficiently low Co concentrations a stable and magnetically more ordered structure can be obtained with excellent electrochemical properties, although a relatively large amount of Ni is present.
|
|
| 4. |
- Karimipour, Masoud, et al.
(författare)
-
Effect of Annealing Temperature on the Structural and Magnetic Properties of Co-Doped TiO2 Nanoparticles via Complex-Polymer Sol-Gel Method
- 2012
-
Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 12:2, s. 950-954
-
Tidskriftsartikel (refereegranskat)abstract
- Co-doped TiO2 nanoparticles were synthesized via non hydrous complex-polymer sol gel method. A series of Co-x:Ti1-xO2 samples with x = 0.01, 0.03, 0.05, 0.08 and 0.10, were prepared and subsequently annealed at 400 degrees, 600 degrees and 800 degrees C. Structural and magnetic properties of Co-x:Ti1-xO2 have been studied by means of X-ray diffraction and DC magnetometry. All samples annealed at 400 degrees C show a paramagnetic behavior with an average grain size of 11 nm. With increasing annealing temperatures a complete crystallization is seen with growth of the cluster size up to 31 nm with clear evidence of a presence of CoTiO3. For all concentrations and annealing conditions no sign of a metallic phase, even at x = 0.10, is seen.
|
|
| 5. |
- Karimipour, Masoud, et al.
(författare)
-
Nanoparticles of Ni/NiO embedded in TiO(2) synthesized by the complex-polymer sol-gel method
- 2011
-
Ingår i: Physica Scripta. - : IOP Publishing. - 0031-8949 .- 1402-4896. ; 84:3, s. 035702-
-
Tidskriftsartikel (refereegranskat)abstract
- Ni-doped TiO(2) nanoparticles were synthesized by the non-hydrous complex-polymer sol-gel method. Titanium isopropoxide was used as precursor and acetyl acetone (AcAc) and citric acid were used as polymer and complex agent, respectively. A series of Ni(x) : Ti(1-x)O(2) samples with x = 0.01, 0.03, 0.05 and 0.10 were prepared and subsequently annealed at 400, 600 and 800 degrees C. The structural and magnetic properties of Ni(x) : Ti(1-x)O(2) were studied by means of x-ray diffraction (XRD) and dc magnetometery. Samples annealed at 400 degrees C attained a particle size of 12 nm with structural phases of anatase, rutile and cubic NiO. From the blocking temperatures of the zero-field-cooled and field-cooled measurements, similar particle sizes (as from XRD) were obtained. The presence of ferro- and antiferromagnetic (AFM) interactions further confirms that the particles have different structural compositions. At 800 degrees C the particles have grown to about 30 nm with either a rutile or NiTiO(3)-type structure. The presence of NiTiO(3) is also seen in the magnetic measurements, which show the characteristic AFM peak at 23 K.
|
|
| 6. |
- Knut, Ronny, et al.
(författare)
-
Magnetic and electronic characterization of highly Co-doped ZnO : An annealing study at the solubility limit
- 2010
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 82:9, s. 094438-
-
Tidskriftsartikel (refereegranskat)abstract
- We report on investigations of the electronic structure and magnetic properties of ZnO doped with 15 at. % Co and postgrowth annealed at temperatures ranging between 250 and 800°C. In particular, we demonstrate how the presence of Co3+, indicative of secondary phases, is manifested in spectroscopy. Through resonant photoemmision spectroscopy we have found that x-ray diffraction in some cases underestimates or does not reveal the presence of secondary phases, possibly due to unrelaxed structures or structural arrangements with sizes below the detection limit. The magnetic properties are in most cases understood by assuming small antiferromagnetic clusters but can also show a behavior indicative of ferromagnetic interactions.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Strömbergsson, Helena, et al.
(författare)
-
Towards proteome-wide interaction models using the proteochemometrics approach
- 2010
-
Ingår i: Molecular Informatics. - : Wiley. - 1868-1743 .- 1868-1751. ; 29:6-7, s. 499-508
-
Tidskriftsartikel (refereegranskat)abstract
- A proteochemometrics model was induced from all interaction data in the BindingDB database, comprizing in all 7078 protein-ligand complexes with representatives from all major drug target categories. Proteins were represented by alignment-independent sequence descriptors holding information on properties such as hydrophobicity, charge, and secondary structure. Ligands were represented by commonly used QSAR descriptors. The inhibition constant (pK(i)) values of protein-ligand complexes were discretized into "high" and "low" interaction activity. Different machine-learning techniques were used to induce models relating protein and ligand properties to the interaction activity. The best was decision trees, which gave an accuracy of 80% and an area under the ROC curve of 0.81. The tree pointed to the protein and ligand properties, which are relevant for the interaction. As the approach does neither require alignments nor knowledge of protein 3D structures virtually all available protein-ligand interaction data could be utilized, thus opening a way to completely general interaction models that may span entire proteomes.
|
|
| 10. |
- Wikberg, Emma, 1982-, et al.
(författare)
-
Fractional domain walls from on-site softening in dipolar bosons
- 2012
-
Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 85:3, s. 033607-
-
Tidskriftsartikel (refereegranskat)abstract
- We study dipolar bosons in a 1D optical lattice and identify a region in parameter space-strong coupling but relatively weak on-site repulsion-hosting a series of stable charge-density-wave (CDW) states whose low-energy excitations, built from fractional domain walls, have remarkable similarities to those of non-Abelian fractional quantum Hall states. Here, a conventional domain wall between translated CDW's may be split by inserting strings of degenerate, but inequivalent, CDW states. Outside these insulating regions, we find numerous supersolids as well as a superfluid regime. The mentioned phases should be accessible experimentally and, in particular, the fractional domain walls can be created in the ground state using single-site addressing, i.e., by locally changing the chemical potential.
|
|
