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Garbrecht, Magnus
Publications (10 of 24) Show all publications
Elofsson, V., Almyras, G., Lü, B., Garbrecht, M., Boyd, R. & Sarakinos, K. (2018). Structure formation in Ag-X (X = Au, Cu) alloys synthesized far-from-equilibrium. Journal of Applied Physics, 123(16)
Open this publication in new window or tab >>Structure formation in Ag-X (X = Au, Cu) alloys synthesized far-from-equilibrium
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2018 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 123, no 16Article in journal (Refereed) Published
Abstract [en]

We employ sub-monolayer, pulsed Ag and Au vapor fluxes, along with deterministic growth simulations, and nanoscale probes to study structure formation in miscible Ag-Au films synthesized under far-from-equilibrium conditions. Our results show that nanoscale atomic arrangement is primarily determined by roughness build up at the film growth front, whereby larger roughness leads to increased intermixing between Ag and Au. These findings suggest a different structure formation pathway as compared to the immiscible Ag-Cu system for which the present study, in combination with previously published data, reveals that no significant roughness is developed, and the local atomic structure is predominantly determined by the tendency of Ag and Cu to phase-separate.

Place, publisher, year, edition, pages
New York: A I P Publishing LLC, 2018
National Category
Inorganic Chemistry Other Physics Topics Atom and Molecular Physics and Optics Condensed Matter Physics Physical Chemistry
Identifiers
urn:nbn:se:liu:diva-147730 (URN)10.1063/1.5018907 (DOI)000431147200150 ()
Note

Funding agencies: Linkoping University via the "LiU Research Fellows Program"; Linkoping University via the "LiU Career Contract" [Dnr-LiU-2015-01510]; Swedish Research Council [VR-2011-5312, VR-2015-04630]

Available from: 2018-05-08 Created: 2018-05-08 Last updated: 2019-06-28Bibliographically approved
Saha, B., Rui Koh, Y., Comparan, J., Sadasivam, S., Schroeder, J., Garbrecht, M., . . . Sands, T. D. (2016). Cross-plane thermal conductivity of (Ti,W)N/(Al,Sc)N metal/semiconductor superlattices. Physical Review B, 93(4), 045311
Open this publication in new window or tab >>Cross-plane thermal conductivity of (Ti,W)N/(Al,Sc)N metal/semiconductor superlattices
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2016 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 93, no 4, p. 045311-Article in journal (Refereed) Published
Abstract [en]

Reduction of cross-plane thermal conductivity and understanding of the mechanisms of heat transport in nanostructured metal/semiconductor superlattices are crucial for their potential applications in thermoelectric and thermionic energy conversion devices, thermal management systems, and thermal barrier coatings. We have developed epitaxial (Ti,W)N/(Al,Sc)N metal/semiconductor superlattices with periodicity ranging from 1 nm to 240 nm that show significantly lower thermal conductivity compared to the parent TiN/(Al, Sc) N superlattice system. The (Ti,W)N/(Al,Sc)N superlattices grow with [001] orientation on the MgO(001) substrates with well-defined coherent layers and are nominally single crystalline with low densities of extended defects. Cross-plane thermal conductivity (measured by time-domain thermoreflectance) decreases with an increase in the superlattice interface density in a manner that is consistent with incoherent phonon boundary scattering. Thermal conductivity values saturate at 1.7W m(-1) K-1 for short superlattice periods possibly due to a delicate balance between long-wavelength coherent phonon modes and incoherent phonon scattering from heavy tungsten atomic sites and superlattice interfaces. First-principles density functional perturbation theory based calculations are performed to model the vibrational spectrum of the individual component materials, and transport models are used to explain the interface thermal conductance across the (Ti,W)N/(Al,Sc)N interfaces as a function of periodicity. The long-wavelength coherent phonon modes are expected to play a dominant role in the thermal transport properties of the short-period superlattices. Our analysis of the thermal transport properties of (Ti,W)N/(Al,Sc)N metal/semiconductor superlattices addresses fundamental questions about heat transport in multilayer materials.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2016
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-125146 (URN)10.1103/PhysRevB.93.045311 (DOI)000368487500010 ()
Note

Funding Agencies|National Science Foundation; U.S. Department of Energy [CBET-1048616]; Defense Advanced Research Projects Agency (DARPA)/Army Research Office [W911NF0810347]; Louis Stokes Alliance for Minority Participation (LSAMP) program; Office of Naval Research [N000141211006]; Swedish Research Council [RAC Frame Program] [2011-6505]; Swedish Research Council [Linnaeus Grant (LiLi-NFM)]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [SFO-Mat-LiU 2009-00971]

Available from: 2016-02-15 Created: 2016-02-15 Last updated: 2017-11-30
Henry, A., Chubarov, M., Czigany, Z., Garbrecht, M. & Högberg, H. (2016). Early stages of growth and crystal structure evolution of boron nitride thin films. Paper presented at 6th International Symposium on Growth of III-Nitrides (ISGN). Japanese Journal of Applied Physics, 55(5), 05FD06
Open this publication in new window or tab >>Early stages of growth and crystal structure evolution of boron nitride thin films
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2016 (English)In: Japanese Journal of Applied Physics, ISSN 0021-4922, E-ISSN 1347-4065, Vol. 55, no 5, p. 05FD06-Article in journal (Refereed) Published
Abstract [en]

A study of the nucleation and crystal structure evolution at the early stages of the growth of sp(2)-BN thin films on 6H-SiC and alpha-Al2O3 substrates is presented. The growth is performed at low pressure and high temperature in a hot wall CVD reactor, using ammonia and triethylboron as precursors, and H-2 as carrier gas. From high-resolution transmission electron microscopy and X-ray thin film diffraction measurements we observe that polytype pure rhombohedral BN (r-BN) is obtained on 6H-SiC substrates. On alpha-Al2O3 an AlN buffer obtained by nitridation is needed to promote the growth of hexagonal BN (h-BN) to a thickness of around 4 nm followed by a transition to r-BN growth. In addition, when r-BN is obtained, triangular features show up in plan-view scanning electron microscopy which are not seen on thin h-BN layers. The formation of BN after already one minute of growth is confirmed by X-ray photoelectron spectroscopy. (C) 2016 The Japan Society of Applied Physics

Place, publisher, year, edition, pages
IOP PUBLISHING LTD, 2016
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-128949 (URN)10.7567/JJAP.55.05FD06 (DOI)000374697600030 ()
Conference
6th International Symposium on Growth of III-Nitrides (ISGN)
Available from: 2016-06-09 Created: 2016-06-07 Last updated: 2018-03-23
Olsson, S., Broitman, E., Garbrecht, M., Birch, J., Hultman, L. & Eriksson, F. (2016). Mechanical and Tribological Properties of AlCuFe Quasicrystal and Al(Si)CuFe Approximant Thin Films. Journal of Materials Research, 31(2), 232-240
Open this publication in new window or tab >>Mechanical and Tribological Properties of AlCuFe Quasicrystal and Al(Si)CuFe Approximant Thin Films
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2016 (English)In: Journal of Materials Research, ISSN 0884-2914, E-ISSN 2044-5326, Vol. 31, no 2, p. 232-240Article in journal (Refereed) Published
Abstract [en]

Multilayered thin films of Al/Cu/Fe have been prepared by magnetron sputtering and annealed into the quasicrystalline or approximant phases, for Al2O3 or Si substrates, respectively. The nanomechanical and nanotribological properties; hardness, elastic modulus, friction and toughness, have been measured using a triboindenter and analytical methods. The approximant phase, annealed at 600 °C for 4 h, proved to be harder and had higher elastic modulus values than the quasicrystalline phase, about, 15.6 GPa and 258 GPa, respectively. The fracture toughness of the approximant, <0.1 MPa/m½, was however inferior to that of the quasicrystals with 1.5 MPa/m½. The friction coefficients were measured in a range of 0.10-0.14 for the quasicrystalline and approximant thin films.

Place, publisher, year, edition, pages
Cambridge University Press, 2016
Keywords
quasicrystal, approximant, thin film, hardness, elastic modulus, friction, toughness, tribology, TEM, STEM, XRD
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-96907 (URN)10.1557/jmr.2015.384 (DOI)000371704900007 ()
Note

Funding agencies:  Knut and Alice Wallenberg Foundation; Swedish Government Strategic Research Area Grant in Materials Science (SFO Mat-LiU) on Advanced Functional Materials

Available from: 2013-08-29 Created: 2013-08-29 Last updated: 2017-12-06Bibliographically approved
Garbrecht, M., Schroeder, J., Hultman, L., Birch, J., Saha, B. & Sands, T. D. (2016). Microstructural evolution and thermal stability of HfN/ScN, ZrN/ScN, and Hf0.5Zr0.5N/ScN metal/semiconductor superlattices. Journal of Materials Science, 51(17), 8250-8258
Open this publication in new window or tab >>Microstructural evolution and thermal stability of HfN/ScN, ZrN/ScN, and Hf0.5Zr0.5N/ScN metal/semiconductor superlattices
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2016 (English)In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 51, no 17, p. 8250-8258Article in journal (Refereed) Published
Abstract [en]

Nitride-based metal/semiconductor superlattices for possible applications as thermoelectric, plasmonic, and hard coating materials have been grown by magnetron sputtering. Since long-time thermal stability of the superlattices is crucial for these applications, the atomic scale microstructure and its evolution under annealing to working temperatures were investigated with high-resolution transmission electron microscopy methods. We report on epitaxial growth of three cubic superlattice systems (HfN/ScN, ZrN/ScN, and Hf0.5Zr0.5N/ScN) that show long-time thermal stability (annealing up to 120 h at 950 degrees C) as monitored by scanning transmission electron microscopy-based energy-dispersive X-ray spectroscopy. No interdiffusion between the metal and semiconductor layers could be observed for any of the present systems under long-time annealing, which is in contrast to earlier attempts on similar superlattice structures based on TiN as the metallic compound. Atomically resolved high-resolution transmission electron microscopy imaging revealed that even though the superlattice curves towards the substrate at regular interval column boundaries originating from threading dislocations close to the substrate interface, the cubic lattice continues coherently across the boundaries. It is found that the boundaries themselves are alloyed along the entire growth direction, while in their vicinity nanometer-size inclusions of metallic phases are observed that could be identified as the zinc blende phase of same stoichiometry as the parent rock salt transition metal nitride phase. Our results demonstrate the longtime thermal stability of metal/semiconductor superlattices based on Zr and Hf nitrides.

Place, publisher, year, edition, pages
SPRINGER, 2016
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-130255 (URN)10.1007/s10853-016-0102-6 (DOI)000378542500038 ()
Note

Funding Agencies|Swedish Research Council [2011-6505, 2013-4018]; Swedish Government [SFO-Mat-LiU 2009-00971]; National Science Foundation; U.S. Department of Energy [CBET-1048616]

Available from: 2016-08-01 Created: 2016-07-28 Last updated: 2017-11-28
Muhammad, J., Chen, Y.-T., Palisaitis, J., Garbrecht, M., Hsiao, C.-L., Persson, P., . . . Birch, J. (2015). Liquid-target Reactive Magnetron Sputter Epitaxy of High Quality GaN(0001ɸ)ɸ Nanorods on Si(111). Materials Science in Semiconductor Processing, 39, 702-710
Open this publication in new window or tab >>Liquid-target Reactive Magnetron Sputter Epitaxy of High Quality GaN(0001ɸ)ɸ Nanorods on Si(111)
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2015 (English)In: Materials Science in Semiconductor Processing, ISSN 1369-8001, E-ISSN 1873-4081, Vol. 39, p. 702-710Article in journal (Refereed) Published
Abstract [en]

Direct current magnetron sputter epitaxy with a liquid Ga sputtering target hasbeen used to grow single-crystal GaN(0001) nanorods directly on Si(111)substrates at different working pressures ranging from 5 to 20 mTorr of pure N2,.The as-grown GaN nanorods exhibit very good crystal quality from bottom to topwithout stacking faults, as determined by transmission electron microscopy. Thecrystal quality is found to increase with increasing working pressure. X-raydiffraction results show that all the rods are highly (0001)-oriented. Thenanorods exhibit an N-polarity, as determined by convergent beam electrondiffraction methods. Sharp and well-resolved 4 K photoluminescence peaks at ~3.474 eV with a FWHM ranging from 1.7 meV to 35 meV are attributed to theintrinsic GaN band edge emission and corroborate the superior structuralproperties of the material. Texture measurements reveal that the rods haverandom in-plane orientation when grown on Si(111) with native oxide, while theyhave an in-plane epitaxial relationship of GaN[110] // Si[110] when grown onsubstrates without surface oxide.

Place, publisher, year, edition, pages
Elsevier, 2015
Keywords
GaN, Nanorods, X-ray Diffraction, TEM, PL, magnetron sputter epitaxy, sputtering
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-84653 (URN)10.1016/j.mssp.2015.05.055 (DOI)000361774100097 ()
Note

Funding: Swedish Foundation for Strategic Research; Swedish Research Council Linnaeus [2008-6572]; Swedish Government Strategic Research Area Grant in Materials Science AFM-SFO MatLiU [2009-00971]; Knut and Alice Wallenberg Foundation

Available from: 2012-10-16 Created: 2012-10-16 Last updated: 2018-03-08Bibliographically approved
Bakoglidis, K. D., Schmidt, S., Garbrecht, M., Ivanov, I. G., Jensen, J., Greczynski, G. & Hultman, L. (2015). Low-temperature growth of low friction wear-resistant amorphous carbon nitride thin films by mid-frequency, high power impulse, and direct current magnetron sputtering. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, 33(5), Article ID 05E112.
Open this publication in new window or tab >>Low-temperature growth of low friction wear-resistant amorphous carbon nitride thin films by mid-frequency, high power impulse, and direct current magnetron sputtering
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2015 (English)In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 33, no 5, article id 05E112Article in journal (Refereed) Published
Abstract [en]

Amorphous carbon nitride (a-CNx) thin films were deposited on steel AISI52100 and Si(001) substrates using mid-frequency magnetron sputtering (MFMS) with an MF bias voltage, high power impulse magnetron sputtering (HiPIMS) with a synchronized HiPIMS bias voltage, and direct current magnetron sputtering (DCMS) with a DC bias voltage. The films were deposited at a low substrate temperature of 150 °C and a N2/Ar flow ratio of 0.16 at the total pressure of 400 mPa. The negative bias voltage (Vs) was varied from 20 V to 120 V in each of the three deposition modes. The microstructure of the films was characterized by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), while the film morphology was investigated by scanning electron microscopy (SEM). All films possessed amorphous microstructure with clearly developed columns extending throughout the entire film thickness. Layers grown with the lowest substrate bias of 20 V exhibited pronounced intercolumnar porosity, independent of the technique used. Voids closed and dense films formed at Vs ≥ 60 V, Vs ≥ 100 V and Vs = 120 V for MFMS, DCMS and HiPIMS, respectively. X-ray photoelectron spectroscopy (XPS) revealed that the nitrogen-to-carbon ratio, N/C, of the films ranged between 0.2 and 0.24. Elastic recoil detection analysis (ERDA) showed that Ar content varied between 0 and 0.8 at% and increases as a function of Vs for all deposition techniques. All films exhibited compressive residual stress, σ, which depends on the growth method; HiPIMS produces the least stressed films with stress between – 0.4 and – 1.2 GPa for all Vs values, while for CNx films deposited by MFMS σ = – 4.2 GPa. Nanoindentation showed a significant increase in film hardness and reduced elastic modulus with increasing Vs for all techniques. The harder films were produced by MFMS with hardness as high as 25 GPa. Low friction coefficients, between 0.05 and 0.06, were recorded for all films. Furthermore, CNx films produced by MFMS and DCMS at Vs = 100 V and 120 V presented a high wear resistance with wear coefficients of k ≤ 2.3 x 10-5 mm3/Nm.

National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-118343 (URN)10.1116/1.4923275 (DOI)000361229000012 ()
Note

On the day of the defence date the status of this article was Manuscript.

Available from: 2015-05-27 Created: 2015-05-27 Last updated: 2017-12-04Bibliographically approved
Chubarov, M., Pedersen, H., Högberg, H., Czigany, Z., Garbrecht, M. & Henry, A. (2015). Polytype pure sp2-BN thin films as dictated by the substrate crystal structure. Chemistry of Materials, 27(5), 1640-1645
Open this publication in new window or tab >>Polytype pure sp2-BN thin films as dictated by the substrate crystal structure
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2015 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 27, no 5, p. 1640-1645Article in journal (Refereed) Published
Abstract [en]

Boron nitride (BN) is a promising semiconductor material, but its current exploration is hampered by difficulties in growth of single crystalline phase-pure thin films. We compare the growth of sp2-BN by chemical vapor deposition on (0001) 6H-SiC and on (0001) α-Al2O3 substrates with an AlN buffer layer. Polytype-pure rhombohedral BN (r-BN) with a thickness of 200 nm is observed on SiC whereas hexagonal BN (h-BN) nucleates and grows on the AlN buffer layer. For the latter case after a thickness of 4 nm, the h-BN growth is followed by r-BN growth to a total thickness of 200 nm. We find that the polytype of the sp2-BN films is determined by the ordering of Si-C or Al-N atomic pairs in the underlying crystalline structure (SiC or AlN). In the latter case the change from h-BN to r-BN is triggered by stress relaxation. This is important for the development of BN semiconductor device technology.

Place, publisher, year, edition, pages
Washington: American Chemical Society (ACS), 2015
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-112577 (URN)10.1021/cm5043815 (DOI)000350919000025 ()
Note

This work was supported by the Swedish Research Council (VR, Grant 621-2013-5585), Carl Tryggers Foundation (No. 12:175), and the CeNano program at Linkoping University. H.H. acknowledges support from the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU No. 2009-00971). Z.C. acknowledges the support of the Bolyai Janos research scholarship of the Hungarian Academy of Sciences. The Knut and Alice Wallenberg (KAW) Foundation is acknowledged for the Electron Microscope Laboratory in Linkoping. Sven G. Andersson is gratefully acknowledged for his technical support of the growth activities.

Available from: 2014-12-04 Created: 2014-12-04 Last updated: 2017-12-05Bibliographically approved
Schroeder, J., Saha, B., Garbrecht, M., Schell, N., Sands, T. D. & Birch, J. (2015). Thermal stability of epitaxial cubic-TiN/(Al,Sc)N metal/semiconductor superlattices. Journal of Materials Science, 50(8), 3200-3206
Open this publication in new window or tab >>Thermal stability of epitaxial cubic-TiN/(Al,Sc)N metal/semiconductor superlattices
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2015 (English)In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 50, no 8, p. 3200-3206Article in journal (Refereed) Published
Abstract [en]

We report on the thermal stability of epitaxial cubic-TiN/(Al,Sc)N metal/semiconductor superlattices with the rocksalt crystal structure for potential plasmonic, thermoelectric, and hard coating applications. TiN/Al0.72Sc0.28N superlattices were annealed at 950 and 1050 A degrees C for 4, 24, and 120 h, and the thermal stability was characterized by high-energy synchrotron-radiation-based 2D X-ray diffraction, high-resolution (scanning) transmission electron microscopy [HR(S)/TEM], and energy dispersive X-ray spectroscopy (EDX) mapping. The TiN/Al0.72Sc0.28N superlattices were nominally stable for up to 4 h at both 950 and 1050 A degrees C. Further annealing treatments for 24 and 120 h at 950 A degrees C led to severe interdiffusion between the layers and the metastable cubic-Al0.72Sc0.28N layers partially transformed into Al-deficient cubic-(Al,Sc)N and the thermodynamically stable hexagonal wurtzite phase with a nominal composition of AlN (h-AlN). The h-AlN grains displayed two epitaxial variants with respect to c-TiN and cubic-(Al,Sc)N. EDX mapping suggests that scandium has a higher tendency for diffusion in TiN/(Al,Sc)N than titanium or aluminum. Our results indicate that the kinetics of interdiffusion and the cubic-to-hexagonal phase transformation place constraints on the design and implementation of TiN/(Al,Sc)N superlattices for high-temperature applications.

Place, publisher, year, edition, pages
Springer Verlag (Germany), 2015
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-116502 (URN)10.1007/s10853-015-8884-5 (DOI)000349969800021 ()
Note

Funding Agencies|Linkoping University; Swedish Research Council [2011-6505]; National Science Foundation; US Department of Energy [CBET-1048616]

Available from: 2015-03-27 Created: 2015-03-27 Last updated: 2017-12-04
Mak, W. C., Selegård, R., Garbrecht, M. & Aili, D. (2014). Probing Zinc-Protein-Chelant Interactions using Gold Nanoparticles Functionalized with Zinc-Responsive Polypeptides. Particle & particle systems characterization, 31(11), 1127-1133
Open this publication in new window or tab >>Probing Zinc-Protein-Chelant Interactions using Gold Nanoparticles Functionalized with Zinc-Responsive Polypeptides
2014 (English)In: Particle & particle systems characterization, ISSN 0934-0866, E-ISSN 1521-4117, Vol. 31, no 11, p. 1127-1133Article in journal (Refereed) Published
Abstract [en]

The coordination of zinc by proteins and various other organic molecules is essential for numerous biological processes, such as in enzymatic catalysis, metabolism and signal transduction. Presence of small molecular chelants can have a profound effect on the bioavailability of zinc and affect critical Zn2+-protein interactions. Zn2+ chelators are also emerging therapeutics for Alzheimer’s diseases because of their preventive effect on zinc promoted amyloid formation. Despite the importance of zinc-protein-chelant interactions in biology and medicine, probing such interactions is  challenging. Here, we introduce an innovative approach for real-time characterization of zinc-protein-chelant interactions using gold nanoparticles (AuNPs) functionalized with a zinc-responsive protein mimetic polypeptide. The peptide functionalized AuNPs aggregate extensively in the presence of Zn2+, triggered by specific Zn2+-mediated polypeptide dimerization and folding, causing a massive red shift of the plasmon band. Chelants affects the Zn2+- polypeptide interaction and thus the aggregation differently depending on their concentrations, zincbinding affinities and coordination numbers, which affect the position of the plasmon band. This system is a simple and powerful tool that provides extensive information about the interactions of chelants in the formation of Zn2+ coordination complexes and is an interesting platform for development of bioanalytical techniques and characterization of chelation-based therapeutics.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2014
Keywords
Gold nanoparticles, zinc, peptide, chelation
National Category
Chemical Sciences
Identifiers
urn:nbn:se:liu:diva-106717 (URN)10.1002/ppsc.201400082 (DOI)000344681700003 ()
Available from: 2014-05-19 Created: 2014-05-19 Last updated: 2019-01-22Bibliographically approved
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