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Tasnadi, Ferenc
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Publikasjoner (10 av 38) Visa alla publikasjoner
Bykov, M., Bykova, E., Koemets, E., Fedotenko, T., Aprilis, G., Glazyrin, K., . . . Dubrovinsky, L. (2018). High-Pressure Synthesis of a Nitrogen-Rich Inclusion Compound ReN8·xN2 with Conjugated Polymeric Nitrogen Chains. Angewandte Chemie International Edition, 57(29), 9048-9053
Åpne denne publikasjonen i ny fane eller vindu >>High-Pressure Synthesis of a Nitrogen-Rich Inclusion Compound ReN8·xN2 with Conjugated Polymeric Nitrogen Chains
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2018 (engelsk)Inngår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 57, nr 29, s. 9048-9053Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A nitrogen-rich compound, ReN(8)xN(2), was synthesized by a direct reaction between rhenium and nitrogen at high pressure and high temperature in a laser-heated diamond anvil cell. Single-crystal X-ray diffraction revealed that the crystal structure, which is based on the ReN8 framework, has rectangular-shaped channels that accommodate nitrogen molecules. Thus, despite a very high synthesis pressure, exceeding 100GPa, ReN(8)xN(2) is an inclusion compound. The amount of trapped nitrogen (x) depends on the synthesis conditions. The polydiazenediyl chains [-N=N-] that constitute the framework have not been previously observed in any compound. Abinitio calculations on ReN(8)xN(2) provide strong support for the experimental results and conclusions.

sted, utgiver, år, opplag, sider
WILEY-V C H VERLAG GMBH, 2018
Emneord
high-energy-density materials; high-pressure chemistry; nitrides; polymeric nitrogen; X-ray diffraction
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-149844 (URN)10.1002/anie.201805152 (DOI)000438195200045 ()29774981 (PubMedID)
Merknad

Funding Agencies|German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) [DU 954-8/1, DU 954-11/1]; Federal Ministry of Education and Research, Germany (BMBF) [5K16WC1]; DFG [FOR2125, FOR 2440]; Ministry of Education and Science of the Russian Federation [14.Y26.31.0005, K2-2017-080]; Swedish Research Council (VR) [2015-04391]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; VINN Excellence Center Functional Nanoscale Materials (FunMat-2) Grant [2016-05156]

Tilgjengelig fra: 2018-08-02 Laget: 2018-08-02 Sist oppdatert: 2018-08-22
Tholander, C., Birch, J., Tasnádi, F., Hultman, L., Palisaitis, J., Persson, P. O., . . . Zukauskaitè, A. (2016). Ab initio calculations and experimental study of piezoelectric YxIn1-xN thin films deposited using reactive magnetron sputter epitaxy. Acta Materialia, 105, 199-206
Åpne denne publikasjonen i ny fane eller vindu >>Ab initio calculations and experimental study of piezoelectric YxIn1-xN thin films deposited using reactive magnetron sputter epitaxy
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2016 (engelsk)Inngår i: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 105, s. 199-206Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

By combining theoretical prediction and experimental verification we investigate the piezoelectric properties of yttrium indium nitride (YxIn1-xN). Ab initio calculations show that the YxIn1-xN wurtzite phase is lowest in energy among relevant alloy structures for 0≤x≤0.5. Reactive magnetron sputter epitaxy was used to prepare thin films with Y content up to x=0.51. The composition dependence of the lattice parameters observed in the grown films is in agreement with that predicted by the theoretical calculations confirming the possibility to synthesize a wurtzite solid solution. An AlN buffer layer greatly improves the crystalline quality and surface morphology of subsequently grown YxIn1-xN films. The piezoelectric response in films with x=0.09 and x=0.14 is observed using piezoresponse force microscopy. Theoretical calculations of the piezoelectric properties predict YxIn1−xN to have comparable piezoelectric properties to ScxAl1-xN.

sted, utgiver, år, opplag, sider
Elsevier, 2016
Emneord
YInN, Thin films, Sputter deposition, Piezoelectricity, Ab initio calculations
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-125918 (URN)10.1016/j.actamat.2015.11.050 (DOI)000370086500023 ()
Tilgjengelig fra: 2016-03-08 Laget: 2016-03-08 Sist oppdatert: 2017-11-30bibliografisk kontrollert
Wang, F., Abrikosov, I., Simak, S., Odén, M., Muecklich, F. & Tasnadi, F. (2016). Coherency effects on the mixing thermodynamics of cubic Ti1-xAlxN/TiN(001) multilayers. PHYSICAL REVIEW B, 93(17), 174201
Åpne denne publikasjonen i ny fane eller vindu >>Coherency effects on the mixing thermodynamics of cubic Ti1-xAlxN/TiN(001) multilayers
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2016 (engelsk)Inngår i: PHYSICAL REVIEW B, ISSN 2469-9950, Vol. 93, nr 17, s. 174201-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

In this work, we discuss the mixing thermodynamics of cubic (B1) Ti1-xAlxN/TiN(001) multilayers. We show that interfacial effects suppress the mixing enthalpy compared to bulk Ti1-xAlxN. The strongest stabilization occurs for compositions in which the mixing enthalpy of bulk Ti1-xAlxN has its maximum. The effect is split into a strain and an interfacial (or chemical) contribution, and we show that both contributions are significant. An analysis of the local atomic structure reveals that the Ti atoms located in the interfacial layers relax significantly different from those in the other atomic layers of the multilayer. Considering the electronic structure of the studied system, we demonstrate that the lower Ti-site projected density of states at epsilon(F) in the Ti1-xAlxN/TiN multilayers compared to the corresponding monolithic bulk explains a decreased tendency toward decomposition.

sted, utgiver, år, opplag, sider
AMER PHYSICAL SOC, 2016
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-129166 (URN)10.1103/PhysRevB.93.174201 (DOI)000375990200003 ()
Merknad

Funding Agencies|Swedish Foundation for Strategic Research (SSF) project SRL [10-0026]; Erasmus Mundus Joint European Doctoral Programme DocMASE; Multiscale computational-design of novel hard nanostructure coatings; Swedish Research Council (VR) [2015-04391, 621-2012-4401, 2014-4750]; Grant of Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Tomsk State University Academic D. I. Mendeleev Fund Program [8.1.18.2015]; LiLi-NFM; Swedish Government Strategic Research Area Grant in Materials Science

Tilgjengelig fra: 2016-06-13 Laget: 2016-06-13 Sist oppdatert: 2018-02-09
Ektarawong, A., Simak, S., Hultman, L., Birch, J., Tasnádi, F., Wang, F. & Alling, B. (2016). Effects of configurational disorder on the elastic properties of icosahedral boron-rich alloys based on B6O, B13C2, and B4C, and their mixing thermodynamics. Journal of Chemical Physics, 144(13), Article ID 134503.
Åpne denne publikasjonen i ny fane eller vindu >>Effects of configurational disorder on the elastic properties of icosahedral boron-rich alloys based on B6O, B13C2, and B4C, and their mixing thermodynamics
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2016 (engelsk)Inngår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 144, nr 13, artikkel-id 134503Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The elastic properties of alloys between boron suboxide (B6O) and boron carbide (B13C2), denoted by (B6O)1−x(B13C2)x, as well as boron carbide with variable carbon content, ranging from B13C2 to B4C are calculated from first-principles. Furthermore, the mixing thermodynamics of (B6O)1−x(B13C2)x is studied. A superatom-special quasirandom structure approach is used for modeling different atomic configurations, in which effects of configurational disorder between the carbide and suboxide structural units, as well as between boron and carbon atoms within the units, are taken into account. Elastic properties calculations demonstrate that configurational  disorder in B13C2, where a part of the C atoms in the CBC chains substitute for B atoms in the B12 icosahedra, drastically increase the Young’s and shear modulus, as compared to an atomically ordered state, B12(CBC). These calculated elastic moduli of the disordered state are in excellent agreement with experiments. Configurational disorder between boron and carbon can also explain the experimentally observed almost constant elastic moduli of boron carbide as the carbon content is changed from B4C to B13C2. The elastic moduli of the (B6O)1−x(B13C2)x system are also practically unchanged with composition if boron-carbon disorder is taken into account. By investigating the mixing thermodynamics of the alloys, in which the Gibbs free energy is determined within the mean-field approximation for the configurational entropy, we outline the pseudo-binary phase diagram of (B6O)1−x(B13C2)x. The phase diagram reveals the existence of a miscibility gap at all temperatures up to the melting point. Also, the coexistence of B6O-rich as well as ordered or disordered B13C2-rich domains in the material prepared through equilibrium routes is predicted.

sted, utgiver, år, opplag, sider
American Institute of Physics (AIP), 2016
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-122425 (URN)10.1063/1.4944982 (DOI)000374527900023 ()27059576 (PubMedID)
Merknad

Funding agencies:Swedish Research Council (VR) [621-2011-4417, 330-2014-6336, 2011-42-59]; CeNano at Linkoping University; Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST "MISiS" [K3-2014-049]; LiLi-

At the time for thesis presentation publication was in status: Manuscript

Tilgjengelig fra: 2015-11-02 Laget: 2015-11-02 Sist oppdatert: 2018-08-14bibliografisk kontrollert
Sangiovanni, D., Tasnadi, F., Hultman, L., Petrov, I., Greene, J. E. & Chirita, V. (2016). N and Ti adatom dynamics on stoichiometric polar TiN(111) surfaces. Surface Science, 649, 72-79
Åpne denne publikasjonen i ny fane eller vindu >>N and Ti adatom dynamics on stoichiometric polar TiN(111) surfaces
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2016 (engelsk)Inngår i: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 649, s. 72-79Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

We use molecular dynamics (MD) based on the modified embedded atom method (MEAM) to determine diffusion coefficients and migration pathways for Ti and N adatoms (Ti-ad and N-ad) on TiN(111). The reliability of the classical model-potential is verified by comparison with density functional theory (DFT) results at 0 K. MD simulations carried out at temperatures between 600 and 1800 K show that both Ti-ad and N-ad favor fcc surface sites and migrate among them by passing through metastable hcp positions. We find that N-ad species are considerably more mobile than Ti-ad on TiN(111); contrary to our previous results on TiN(001). In addition, we show that lattice vibrations at finite temperatures strongly modify the potential energy landscape and result in smaller adatom migration energies, E-a = 1.03 for Ti-ad and 0.61 eV for N-ad, compared to 0 K values E-aOK = 1.55 (Ti-ad) and 0.79 eV (N-ad). We also demonstrate that the inclusion of dipole corrections, neglected in previous DFT calculations, is necessary in order to obtain the correct formation energies for polar surfaces such as TiN(111). (C) 2016 Elsevier B.V. All rights reserved.

sted, utgiver, år, opplag, sider
ELSEVIER SCIENCE BV, 2016
Emneord
Surface diffusion; Nitrides; Molecular dynamics; Density functional theory; Polar surfaces
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-130423 (URN)10.1016/j.susc.2016.01.031 (DOI)000379097000012 ()
Merknad

Funding Agencies|Knut and Alice Wallenberg Foundation [2011.0094]; Swedish Research Council (VR) [2014-5790]; Linkoping Linnaeus Initiative LiLi-NFM [2008-6572]; Swedish Government Strategic Research Area Grant in Materials Science on Advanced Functional Materials through Swedens innovation agency VINNOVA [MatLiU 2009-00971]

Tilgjengelig fra: 2016-08-07 Laget: 2016-08-05 Sist oppdatert: 2019-06-28
Tholander, C., Tasnadi, F., Abrikosov, I., Hultman, L., Birch, J. & Alling, B. (2015). Large piezoelectric response of quarternary wurtzite nitride alloys and its physical origin from first principles. Physical Review B. Condensed Matter and Materials Physics, 92(17), 174119
Åpne denne publikasjonen i ny fane eller vindu >>Large piezoelectric response of quarternary wurtzite nitride alloys and its physical origin from first principles
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2015 (engelsk)Inngår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 92, nr 17, s. 174119-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The potential of quarternary wurtzite TMx/2Mx/2Al1-xN (TM = Ti, Zr, Hf; M = Mg, Ca, Zn) alloys for piezoelectric applications is investigated using first-principles calculations. All considered alloys show increased piezoelectric response compared to pure AlN, and competing with the best ternary system proven to date: ScAlN. (Zr, Hf)(x/2)(Mg, Ca)(x/2)Al1-xN alloys are particularly promising. Calculations reveal positive mixing enthalpies indicative for phase separating systems; their values are smaller compared to related nitride alloys, which still can be grown as metastable thin films. The wurtzite phase of the alloys is lowest in energy at least up to x = 0.5 and for Tix/2Znx/2Al1-xN in the full composition range. Moreover, calculations reveal that wurtzite TM0.5Zn0.5N (TM = Ti, Zr, Hf) are piezoelectric alloys with d(33,f) = 19.95, 29.89, and 24.65 pC/N respectively, up to six times that of AlN. Finally, we discuss the physical origin behind the increased piezoelectric response and show that the energy difference between tetrahedrally coordinated zinc-blende (B3) and the layered hexagonal (B-k) phases of the TM0.5M0.5N alloy can be used as a descriptor in a high-throughput search for complex wurtzite alloys with high piezoelectric response.

sted, utgiver, år, opplag, sider
AMER PHYSICAL SOC, 2015
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-123799 (URN)10.1103/PhysRevB.92.174119 (DOI)000365506400001 ()
Merknad

Funding Agencies|Knut and Alice Wallenberg Foundation Scholar Grant; Swedish Research Council (VR) Linkoping Linnaeus Initiative LiLi-NFM [2008-6572]; Swedish Government Strategic Research Area Grant in Materials Science on Advanced Functional Materials [MatLiU 2009-00971]; Swedish Research Council [621-2011-4417, 330-2014-6336]; Swedish Foundation for Strategic Research (SSF) Programme SRL [10-0026]; Swedish Research Council (VR) [621-2011-4426]

Tilgjengelig fra: 2016-01-11 Laget: 2016-01-11 Sist oppdatert: 2017-11-30
Tasnadi, F., Wang, F., Odén, M. & Abrikosov, I. (2015). Special quasirandom structure method in application for advanced properties of alloys: A study on Ti0.5Al0.5N and TiN/Ti0.5Al0.5N multilayer. Computational materials science, 103, 194-199
Åpne denne publikasjonen i ny fane eller vindu >>Special quasirandom structure method in application for advanced properties of alloys: A study on Ti0.5Al0.5N and TiN/Ti0.5Al0.5N multilayer
2015 (engelsk)Inngår i: Computational materials science, ISSN 0927-0256, E-ISSN 1879-0801, Vol. 103, s. 194-199Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The special quasirandom structure (SQS) approach is a successful technique for modelling of alloys, however it breaks inherently the point symmetry of the underlying crystal lattice. We demonstrate that monocrystalline and polycrystalline elastic moduli can scatter significantly depending on the chosen SQS model and even on the supercell orientation in space. Also, we demonstrate that local disturbances, such as vacancies or interfaces change the SQS configuration in a way, that significantly affects the values of the calculated physical properties. Moreover, the diversity of local environments in random alloys results in a large variation of the calculated local properties. We underline that improperly chosen, generated or handled SQS may result in erroneous theoretical findings. The challenges of the SQS method are discussed using bulk Ti0.5Al0.5N alloy and TiN/Ti0.5Al0.5N multilayer as model systems. We present methodological corrections for the mindful application of this approach in studies of advanced properties of alloys.

sted, utgiver, år, opplag, sider
Elsevier, 2015
Emneord
Modelling alloys; Special quasirandom structure approach; Elastic constants; Vacancy formation energy; Multilayers
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-118022 (URN)10.1016/j.commatsci.2015.03.030 (DOI)000353377100024 ()
Merknad

Funding Agencies|SSF project Designed Multicomponent coatings, MultiFilms; Erasmus Mundus Programme of the European Commission within the Doctoral Programme DocMASE; Grant of Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Tomsk State University Academic D.I. Mendeleev Fund Program; Swedish Research Council (VR)

Tilgjengelig fra: 2015-05-21 Laget: 2015-05-20 Sist oppdatert: 2018-02-09
Žukauskaitė, A., Tholander, C., Tasnádi, F., Alling, B., Pališaitis, J., Lu, J., . . . Birch, J. (2015). Stabilization of Wurtzite Sc0.4Al0.6N in Pseudomorphic Epitaxial ScxAl1-xN/InyAl1-yN Superlattices. Acta Materialia, 94, 101-110
Åpne denne publikasjonen i ny fane eller vindu >>Stabilization of Wurtzite Sc0.4Al0.6N in Pseudomorphic Epitaxial ScxAl1-xN/InyAl1-yN Superlattices
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2015 (engelsk)Inngår i: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 94, s. 101-110Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Pseudomorphic stabilization in wurtzite ScxAl1-xN/AlN and ScxAl1-xN/InyAl1-yN superlattices (x=0.2, 0.3, and 0.4; y=0.2-0.72), grown by reactive magnetron sputter epitaxy was investigated. X-ray diffraction and transmission electron microscopy show that in ScxAl1-xN/AlN superlattices the compressive biaxial stresses due to positive lattice mismatch in Sc0.3Al0.7N and Sc0.4Al0.6N lead to loss of epitaxy, although the structure remains layered. For the negative lattice mismatched In-rich ScxAl1-xN/InyAl1-yN superlattices a tensile biaxial stress promotes the stabilization of wurtzite ScxAl1-xN even for the highest investigated concentration x=0.4. Ab initio calculations with fixed in-plane lattice parameters show a reduction in mixing energy for wurtzite ScxAl1-xN under tensile stress when x≥0.375 and support the experimental results.

sted, utgiver, år, opplag, sider
Elsevier, 2015
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-103831 (URN)10.1016/j.actamat.2015.04.033 (DOI)000357143500010 ()
Tilgjengelig fra: 2014-01-29 Laget: 2014-01-29 Sist oppdatert: 2017-12-06bibliografisk kontrollert
Shulumba, N., Hellman, O., Rogström, L., Raza, Z., Tasnádi, F., Abrikosov, I. & Odén, M. (2015). Temperature-dependent elastic properties of Ti1−xAlxN alloys. Applied Physics Letters, 107(23)
Åpne denne publikasjonen i ny fane eller vindu >>Temperature-dependent elastic properties of Ti1−xAlxN alloys
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2015 (engelsk)Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 107, nr 23Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Ti1−xAlxN is a technologically important alloy that undergoes a process of high temperature age-hardening that is strongly influenced by its elastic properties. We have performed first principles calculations of the elastic constants and anisotropy using the newly developed symmetry imposed force constant temperature dependent effective potential method, that include lattice vibrations and therefore the effects of temperature, including thermal expansion and intrinsic anharmonicity. These are compared with in situ high temperature x-ray diffraction measurements of the lattice parameter. We show that anharmonic effects are crucial to the recovery of finite temperature elasticity. The effects of thermal expansion and intrinsic anharmonicity on the elastic constants are of the same order, and cannot be considered separately. Furthermore, the effect of thermal expansion on elastic constants is such that the volume change induced by zero point motion has a significant effect. For TiAlN, the elastic constants soften non-uniformly with temperature: C11 decreases substantially when the temperature increases for all compositions, resulting in an increased anisotropy. These findings suggest that an increased Al content and annealing at higher temperatures will result in a harder alloy.

HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-122957 (URN)10.1063/1.4936896 (DOI)000367010800017 ()
Merknad

Funding agencies: Swedish Research Council (VR) [621-2011-4426, 621-2012-4401, 637-2013-7296]; Swedish Foundation for Strategic Research (SSF) [RMA08-0069, SRL10-0026]; VINNOVA [2013-02355(MC2)]; Erasmus Mundus Joint European Doctoral Program DocMASE; Ministry of Education

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Tilgjengelig fra: 2015-11-30 Laget: 2015-11-30 Sist oppdatert: 2017-12-01bibliografisk kontrollert
Ghafoor, N., Lind, H., Tasnadi, F., Abrikosov, I. & Odén, M. (2014). Anomalous epitaxial stability of (001) interfaces in ZrN/SiNx multilayers. APL Materials, 2(4), 046106
Åpne denne publikasjonen i ny fane eller vindu >>Anomalous epitaxial stability of (001) interfaces in ZrN/SiNx multilayers
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2014 (engelsk)Inngår i: APL Materials, ISSN 2166-532X, Vol. 2, nr 4, s. 046106-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Isostructural stability of B1-NaCl type SiN on (001) and (111) oriented ZrN surfaces is studied theoretically and experimentally. The ZrN/SiNx/ZrN superlattices with modulation wavelength of 3.76 nm (dSiNx similar to 0.4 nm) were grown by dc-magnetron sputtering on MgO(001) and MgO(111). The results indicate that 0.4 nm thin SiNx layers utterly influence the preferred orientation of epitaxial growth: on MgO(001) cube-on-cube epitaxy of ZrN/SiNx superlattices were realized whereas multilayers on MgO(111) surface exhibited an unexpected 002 texture with a complex fourfold 90 degrees-rotated in-plane preferred orientation. Density functional theory calculations confirm stability of a (001) interface with respect to a (111) which explains the anomaly.

sted, utgiver, år, opplag, sider
American Institute of Physics, 2014
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-107456 (URN)10.1063/1.4870876 (DOI)000336083600007 ()
Tilgjengelig fra: 2014-06-12 Laget: 2014-06-12 Sist oppdatert: 2015-03-16bibliografisk kontrollert
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