Search

Your search keyword '"Thersleff T"' showing total 110 results
Start Over Author "Thersleff T"
110 results on '"Thersleff T"'

1. The Effect of 45{\deg} Grain Boundaries and associated Fe particles on Jc and resistivity in Ba(Fe0.9Co0.1)2As2 Thin Films

Author

Hänisch, J., Iida, K., Kurth, F., Thersleff, T., Trommler, S., Reich, E., Hühne, R., Schultz, L., and Holzapfel, B.

Subjects
Condensed Matter - Superconductivity
Abstract

The anisotropy of the critical current density Jc depends in general on both the properties of the flux lines (such as line tension, coherence length and penetration depth) and the properties of the defects (such as density, shape, orientation etc.). Whereas the Jc anisotropy in microstructurally clean films can be scaled to an effective magnetic field containing the Ginzburg-Landau anisotropy term, it is in general not possible (or only in a limited field range) for samples containing extended defects. Here, the Jc anisotropy of a Co-doped BaFe2As2 sample with 45{\deg} [001] tilt grain boundaries (GBs), i.e. grain boundaries created by 45{\deg} in-plane rotated grains, as well as extended Fe particles is investigated. This microstructure leads to c-axis correlated pinning, both due to the GBs and the Fe particles and manifests in a c-axis peak in the Jc anisotropy at low magnetic fields and a deviation from the anisotropic Ginzburg-Landau scaling at higher fields. Strong pinning at ellipsoidal extended defects, i.e. the Fe particles, is discussed, and the full Jc anisotropy is fitted successfully with the vortex path model. The results are compared to a sample without GBs and Fe particles. 45{\deg} GBs seem to be good pinning centers rather than detrimental to current flow., Comment: 8 pages, 7 figures, CEC-ICMC 2013 proceeding, accepted for publication in Advances in Cryogenic Engineering (Materials)

Published
2013
Full Text
View/download PDF

2. Influenced of Fe buffer thickness on the crystalline quality and the transport properties of Fe/Ba(Fe1-xCox)2As2 bilayers

Author

Iida, K., Haindl, S., Thersleff, T., Haenishc, J., Kurth, F., Kidszun, M., Huehne, R., Moench, I., Schultz, L., Holzapfel, B., and Heller, R.

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Materials Science
Abstract

The implementation of an Fe buffer layer is a promising way to obtain epitaxial growth of Co-doped BaFe2As2 (Ba-122). However, the crystalline quality and the superconducting properties of Co-doped Ba-122 are influenced by the Fe buffer layer thickness, dFe. The well-textured growth of the Fe/Ba-122 bilayer with dFe = 15 nm results in a high Jc of 0.45 MAcm$^{-2}$ at 12 K in self-field, whereas a low Jc value of 61000 Acm$^{-2}$ is recorded for the bilayer with dFe = 4 nm at the corresponding reduced temperature due to the presence of grain boundaries.

Published
2010
Full Text
View/download PDF

3. Critical current scaling and anisotropy in oxypnictide superconductors

Author

Kidszun, M., Haindl, S., Thersleff, T., Haenisch, J., Kauffmann, A., Iida, K., Freudenberger, J., Schultz, L., and Holzapfel, B.

Subjects
Condensed Matter - Superconductivity
Abstract

Investigating the anisotropy of superconductors permits an access to fundamental properties. Having succeeded in the fabrication of epitaxial superconducting LaFeAs(O,F) thin films we performed an extensive study of electrical transport properties. In face of multiband superconductivity we can demonstrate that a Blatter scaling of the angular dependent critical current densities can be adopted, although being originally developed for single band superconductors. In contrast to single band superconductors the mass anisotropy of LaFeAs(O,F) is temperature dependent. A very steep increase of the upper critical field and the irreversibility field can be observed at temperatures below 6K, indicating that the band with the smaller gap is in the dirty limit. This temperature dependence can be theoretically described by two dominating bands responsible for superconductivity. A pinning force scaling provides insight into the prevalent pinning mechanism and can be specified in terms of the Kramer model., Comment: 7 pages, 13 figures

Published
2010
Full Text
View/download PDF

4. Scaling behaviour of the critical current in clean epitaxial Ba(Fe1-xCox)2As2 thin films

Author

Iida, K., Haenisch, J., Thersleff, T., Kurth, F., Kidszun, M., Haindl, S., Huehne, R., Schultz, L., and Holzapfel, B.

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Materials Science
Abstract

The angular-dependent critical current density, Jc(theta), and the upper critical field, Hc2(theta), of epitaxial Ba(Fe1-xCox)2As2 thin films have been investigated. No Jc(theta) peaks for H || c were observed regardless of temperatures and magnetic fields. In contrast, Jc(theta) showed a broad maximum at theta=90 degree, which arises from intrinsic pinning. All data except at theta=90 degree can be scaled by the Blatter plot. Hc2(theta) near Tc follows the anisotropic Ginzburg-Landau expression. The mass anisotropy increased from 1.5 to 2 with increasing temperature, which is an evidence for multi-band superconductivity., Comment: Accepted in Physical Review B rapid communications

Published
2010
Full Text
View/download PDF

5. LaFeAsO$_{1-x}$F$_{x}$ thin films: high upper critical fields and evidence of weak link behavior

Author

Haindl, S., Kidszun, M., Kauffmann, A., Nenkov, K., Kozlova, N., Freudenberger, J., Thersleff, T., Haenisch, J., Werner, J., Reich, E., Schultz, L., and Holzapfel, B.

Subjects
Condensed Matter - Superconductivity
Abstract

High-quality superconducting LaFeAsO$_{1-x}$F$_{x}$ thin films were grown on single crystalline LaAlO$_{3}$ substrates with critical temperatures (onset) up to 28 K. Resistive measurements in high magnetic fields up to 40 T reveal a paramagnetically limited upper critical field, $\mu_{0}H_{c2}$(0) around 77 T and a remarkable steep slope of -7.5 T/K near $T_{c}$. From transport measurements we observed a weak link behavior in low magnetic fields and the evidence for a broad reversible regime., Comment: 4 pages, 4 figures, Phys. Rev. Lett. (accepted)

Published
2009

13. Preparation of conductive buffer architectures based on IBAD-TiN

Author

Guth, K., Huhne, R., Matias, V., Rowley, J., Thersleff, T., Schultz, L., and Holzapfel, B.

Subjects
Barium compounds -- Electric properties, Barium compounds -- Magnetic properties, Coating processes -- Analysis, Copper oxide superconductors -- Electric properties, Copper oxide superconductors -- Magnetic properties, Ion bombardment -- Usage, Superconductivity -- Analysis, Titanium compounds -- Electric properties, Titanium compounds -- Magnetic properties, Yttrium -- Electric properties, Yttrium -- Magnetic properties, Business, Electronics, Electronics and electrical industries
Published
2009

17. Cu-depleted patches induced by presence of K during growth of CIGS absorbers

Author

Donzel-Gargand, Olivier, Thersleff, T., Keller, Jan, Törndahl, Tobias, Larsson, Fredrik, Wallin, E., Stolt, Lars, and Edoff, Marika

Subjects
Annan materialteknik, Other Materials Engineering, Energy Systems, Energisystem
Abstract

The conversion efficiency of the CIGS thin film solar cells has rapidly increased since introduction of the heavier alkali-doping (K, Rb, Cs). While the exclusive introduction of Na in the CIGS films has led to efficiencies up to 20,4% 1, the latest K, Rb or Cs post deposition treatments (PDT) have increased the efficiency to 22,6% 2. The exact role of this heavy-alkali PDT is still under discussion but three explanations have been discussed in the literature. First, that the heavy alkali PDT facilitates CdCu substitution, that results in an enhanced absorber type inversion, moving the p-n junction further into the CIGS bulk 3. Second, that the main effect from heavy alkali PDT is due to the formation of a K-In-Se2 layer, that passivates defects at the CIGS surface, reducing interface recombination 4. And third, that the heavy alkali PDT induces a Cu depletion at the surface of the CIGS which, by increasing the local Fermi level, increases the band bending; thus creating a higher potential barrier for holes to recombine 5.

Published
2017

18. Thin film growth of Fe-based superconductors: From fundamental properties to functional devices

Author

Haindl, S., Kidszun, M., Oswald, S., Hess, C., Büchner, B., Kölling, S., Wilde, L., Thersleff, T., Yurchenko, V.V., Jourdan, M., Hiramatsu, H., Hosono, H., and Publica

Abstract

Fe-based superconductors bridge a gap between MgB2 and the cuprate high temperature superconductors as they exhibit multiband character and transition temperatures up to around 55 K. Investigating Fe-based superconductors thus promises answers to fundamental questions concerning the Cooper pairing mechanism, competition between magnetic and superconducting phases, and a wide variety of electronic correlation effects. The question addressed in this review is, however, is this new class of superconductors also a promising candidate for technical applications? Superconducting film-based technologies range from high-current and high-field applications for energy production and storage to sensor development for communication and security issues and have to meet relevant needs of today's society and that of the future. In this review we will highlight and discuss selected key issues for Fe-based superconducting thin film applications. We initially focus our discussion on the understanding of physical properties and actual problems in film fabrication based on a comparison of different observations made in the last few years. Subsequently we address the potential for technological applications according to the current situation.

Published
2014

27. Influence of Fe buffer thickness on the crystalline quality and the transport properties of Fe/Ba(Fe1-xCox)(2)As-2 bilayers

Author

Iida, K., Haindl, S., Thersleff, T., Haenisch, J., Kurth, F., Kidszun, M., Huehne, R., Moench, I., Schultz, L., Holzapfel, B., Heller, R., Iida, K., Haindl, S., Thersleff, T., Haenisch, J., Kurth, F., Kidszun, M., Huehne, R., Moench, I., Schultz, L., Holzapfel, B., and Heller, R.

Abstract

The implementation of an Fe buffer layer is a promising way to obtain epitaxial growth of Co-doped BaFe2As2 (Ba-122). However, the crystalline quality and the superconducting properties of Co-doped Ba-122 are influenced by the Fe buffer layer thickness, d(Fe). The well-textured growth of the Fe/Ba-122 bilayer with d(Fe) = 15 nm results in a high J(c) of 0.45 MA cm(-2) at 12 K in self-field, whereas a low J(c) value of 61 000 A cm(-2) is recorded for the bilayer with d(Fe) = 4 nm at the corresponding reduced temperature due to the presence of grain boundaries. (C) 2010 American Institute of Physics. [doi:10.1063/1.3509418]

Published
2010

28. The Effect of 45° Grain Boundaries and associated Fe particles on Jc and resistivity in Ba(Fe0.9Co0.1)2As2 Thin Films.

Author

Hänisch, J., Iida, K., Kurth, F., Thersleff, T., Trommler, S., Reich, E., Hühne, R., Schultz, L., and Holzapfel, B.

Subjects
CRITICAL current density (Superconductivity), CRYSTAL grain boundaries, IRON compounds, ELECTRICAL resistivity, BARIUM compounds, THIN films, ANISOTROPIC crystals, MAGNETIC fields
Abstract

The anisotropy of the critical current density Jc depends in general on both the properties of the flux lines (such as line tension, coherence length and penetration depth) and the properties of the defects (such as density, shape, orientation etc.). Whereas the Jc anisotropy in microstructurally clean films can be scaled to an effective magnetic field containing the Ginzburg-Landau anisotropy term, it is in general not possible (or only in a limited field range) for samples containing extended defects. Here, the Jc anisotropy of a Co-doped BaFe2As2 sample with 45° [001] tilt grain boundaries (GBs), i.e. grain boundaries created by 45° in-plane rotated grains, as well as extended Fe particles is investigated. This microstructure leads to c-axis correlated pinning, both due to the GBs and the Fe particles and manifests in a c-axis peak in the Jc anisotropy at low magnetic fields and a deviation from the anisotropic Ginzburg-Landau scaling at higher fields. Strong pinning at ellipsoidal extended defects, i.e. the Fe particles, is discussed, and the full Jc anisotropy is fitted successfully with the vortex path model. The results are compared to a sample without GBs and Fe particles. 45° GBs seem to be good pinning centers rather than detrimental to current flow. [ABSTRACT FROM AUTHOR]

Published
2014
Full Text
View/download PDF

37. Fabrication of superconducting oxypnictide thin films

Author

Kidszun, M., primary, Haindl, S., additional, Thersleff, T., additional, Werner, J., additional, Langer, M., additional, Hänisch, J., additional, Iida, K., additional, Reich, E., additional, Schultz, L., additional, and Holzapfel, B., additional

Published
2010
Full Text
View/download PDF

49. Influence of Fe buffer thickness on the crystalline quality and the transport properties of Fe/Ba(Fe1-xCox)2As2 bilayers.

Author

Iida, K., Haindl, S., Thersleff, T., Hänisch, J., Kurth, F., Kidszun, M., Hühne, R., Mönch, I., Schultz, L., Holzapfel, B., and Heller, R.

Subjects
IRON, EPITAXY, CRYSTAL grain boundaries, TEMPERATURE effect, BILAYER lipid membranes, SUPERCONDUCTORS, SEMICONDUCTOR doping
Abstract

The implementation of an Fe buffer layer is a promising way to obtain epitaxial growth of Co-doped BaFe2As2 (Ba-122). However, the crystalline quality and the superconducting properties of Co-doped Ba-122 are influenced by the Fe buffer layer thickness, dFe. The well-textured growth of the Fe/Ba-122 bilayer with dFe=15 nm results in a high Jc of 0.45 MA cm-2 at 12 K in self-field, whereas a low Jc value of 61 000 A cm-2 is recorded for the bilayer with dFe=4 nm at the corresponding reduced temperature due to the presence of grain boundaries. [ABSTRACT FROM AUTHOR]

Published
2010
Full Text
View/download PDF

50. Coherent interfacial bonding on the FeAs tetrahedron in Fe/Ba(Fe1-xCox)2As2 bilayers.

Author

Thersleff, T., Iida, K., Haindl, S., Kidszun, M., Pohl, D., Hartmann, A., Kurth, F., Hänisch, J., Hühne, R., Rellinghaus, B., Schultz, L., and Holzapfel, B.

Subjects
*CRYSTAL growth, *COHERENCE (Physics), *PULSED laser deposition, *TRANSMISSION electron microscopy, *FERROMAGNETIC materials, *HETEROSTRUCTURES
Abstract

We demonstrate the growth of epitaxial Fe/Ba(Fe1-xCox)2As2 bilayers on MgO(001) and (La,Sr)(Al,Ta)O3(001) single crystal substrates using pulsed laser deposition (PLD). This architecture produces a coherent interfacial bond between body-centered cubic iron and Ba(Fe1-xCox)2As2 (Ba–122). The superconducting transition temperatures for both bilayers remain close to that of the PLD target. Direct observation of interfacial bonding between Fe and the Ba–122 FeAs sublattice by atomic resolution transmission electron microscopy implies that this bilayer architecture may work for other iron pnictide systems and pave the way for their fabrication into superconducting/ferromagnetic heterostructures. [ABSTRACT FROM AUTHOR]

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results