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Schmidt, Susann
Publications (10 of 25) Show all publications
Hänninen, T., Schmidt, S., Ivanov, I. G., Jensen, J., Hultman, L. & Högberg, H. (2018). Silicon carbonitride thin films deposited by reactive high power impulse magnetron sputtering. Surface & Coatings Technology, 335, 248-256
Open this publication in new window or tab >>Silicon carbonitride thin films deposited by reactive high power impulse magnetron sputtering
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2018 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 335, p. 248-256Article in journal (Refereed) Published
Abstract [en]

Amorphous silicon carbonitride thin films for biomedical applications were deposited in an industrial coating unit from a silicon target in different argon/nitrogen/acetylene mixtures by reactive high power impulse magnetron sputtering (rHiPIMS). The effects of acetylene (C2H2) flow rate, substrate temperature, substrate bias voltage, and HiPIMS pulse frequency on the film properties were investigated. Low C2H2 flow rates (<10 sccm) resulted in silicon nitride-like film properties, seen from a dense morphology when viewed in cross-sectional scanning electron microscopy, a hardness up to ∼22 GPa as measured by nanoindentation, and Si-N bonds dominating over Si-C bonds in X-ray photoelectron spectroscopy core-level spectra. Higher C2H2 flows resulted in increasingly amorphous carbon-like film properties, with a granular appearance of the film morphology, mass densities below 2 g/cm3 as measured by X-ray reflectivity, and a hardness down to 4.5 GPa. Increasing substrate temperatures and bias voltages resulted in slightly higher film hardnesses and higher compressive residual stresses. The film H/E ratio showed a maximum at film carbon contents ranging between 15 and 30 at.% and at elevated substrate temperatures from 340 °C to 520 °C.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Magnetron sputtering, Silicon carbonitride, Acetylene, Hardness, H/E
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-145178 (URN)10.1016/j.surfcoat.2017.12.037 (DOI)000424720800028 ()
Funder
EU, FP7, Seventh Framework Programme, GA-310477Carl Tryggers foundation , 15:219; 14:431
Available from: 2018-02-13 Created: 2018-02-13 Last updated: 2018-04-03
Schmidt, S., Czigany, Z., Wissting, J., Greczynski, G., Janzén, E., Jensen, J., . . . Hultman, L. (2016). A comparative study of direct current magnetron sputtering and high power impulse magnetron sputtering processes for CNX thin film growth with different inert gases. Diamond and related materials, 64, 13-26
Open this publication in new window or tab >>A comparative study of direct current magnetron sputtering and high power impulse magnetron sputtering processes for CNX thin film growth with different inert gases
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2016 (English)In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, Vol. 64, p. 13-26Article in journal (Refereed) Published
Abstract [en]

Reactive direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS) discharges of carbon in different inert gas mixtures (N-2/Ne, N-2/Ar, and N-2/Kr) were investigated for the growth of carbon-nitride (CNX) thin films. Ion mass spectrometry showed that energies of abundant plasma cations are governed by the inert gas and the N-2-to-inert gas flow ratios. The population of ion species depends on the sputter mode; HiPIMS yields approximately ten times higher flux ratios of ions originating from the target to process gas ions than DCMS. Exceptional are discharges in Ne with N-2-to-Ne flow ratios &lt;20%. Here, cation energies and the amount of target ions are highest without influence on the sputter mode. CNX thin films were deposited in 14% N-2/inert gas mixtures at substrate temperatures of 110 degrees C and 430 degrees C. The film properties show a correlation to the substrate temperature, the applied inert gas and sputter mode. The mechanical performance of the films is mainly governed by their morphology and composition, but not by their microstructure. Amorphous and fullerene-like CN0.14 films exhibiting a hardness of similar to 15 GPa and an elastic recovery of similar to 90% were deposited at 110 degrees C in reactive Kr atmosphere by DCMS and HiPIMS.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE SA, 2016
Keywords
Magnetron sputtering; Inert gases; Plasma analysis; Langmuir probe measurement; CNX film stress; CNX hardness
National Category
Inorganic Chemistry Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-128146 (URN)10.1016/j.diamond.2016.01.009 (DOI)000374608100003 ()
Note

Funding Agencies|Carl Tryggers Foundation for Scientific Research; Hungarian Academy of Sciences

Available from: 2016-05-19 Created: 2016-05-19 Last updated: 2017-11-30
Pettersson, M., Bryant, M., Schmidt, S., Engqvist, H., Hall, R. M., Neville, A. & Persson, C. (2016). Dissolution behaviour of silicon nitride coatings for joint replacements. Materials science & engineering. C, biomimetic materials, sensors and systems, 62, 497-505
Open this publication in new window or tab >>Dissolution behaviour of silicon nitride coatings for joint replacements
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2016 (English)In: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 62, p. 497-505Article in journal (Refereed) Published
Abstract [en]

In this study, the dissolution rate of SiNx coatings was investigated as a function of coating composition, in comparison to a cobalt chromium molybdenum alloy (CoCrMo) reference. SiNx coatings with N/Si ratios of 03, 0.8 and 1.1 were investigated. Electrochemical measurements were complemented with solution (inductively coupled plasma techniques) and surface analysis (vertical scanning interferometry and x-ray photoelectron spectroscopy). The dissolution rate of the SiNx coatings was evaluated to 0.2-1.4 nm/day, with a trend of lower dissolution rate with higher N/Si atomic ratio in the coating. The dissolution rates of the coatings were similar to or lower than that of CoCrMo (0.7-1.2 nm/day). The highest nitrogen containing coating showed mainly Si-N bonds in the bulk as well as at the surface and in the dissolution area. The lower nitrogen containing coatings showed Si-N and/or Si-Si bonds in the bulk and an increased formation of Si-O bonds at the surface as well as in the dissolution area. The SiNx coatings reduced the metal ion release from the substrate. The possibility to tune the dissolution rate and the ability to prevent release of metal ions encourage further studies on SiNx coatings for joint replacements.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2016
Keywords
Silicon nitride; Cobalt chromium; Coating; Dissolution; Corrosion; Mass loss; Joint replacement
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-127409 (URN)10.1016/j.msec.2016.01.049 (DOI)000372759100062 ()26952452 (PubMedID)
Note

Funding Agencies|European Union [GA-310477]; Carl Tryggers Foundation for Scientific Research [CTS 14:431]

Available from: 2016-05-02 Created: 2016-04-26 Last updated: 2017-11-30
Pfeiffer, D., Resnati, F., Birch, J., Etxegarai, M., Hall-Wilton, R., Höglund, C., . . . Thuiner, P. (2016). First measurements with new high-resolution gadolinium-GEM neutron detectors. Journal of Instrumentation, 11(P05011)
Open this publication in new window or tab >>First measurements with new high-resolution gadolinium-GEM neutron detectors
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2016 (English)In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, no P05011Article in journal (Refereed) Published
Abstract [en]

European Spallation Source instruments like the macromolecular diffractometer (NMX) require an excellent neutron detection efficiency, high-rate capabilities, time resolution, and an unprecedented spatial resolution in the order of a few hundred micrometers over a wide angular range of the incoming neutrons. For these instruments solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are a promising option. A GEM detector with gadolinium converter was tested on a cold neutron beam at the IFE research reactor in Norway. The mu TPC analysis, proven to improve the spatial resolution in the case of B-10 converters, is extended to gadolinium based detectors. For the first time, a Gd-GEM was successfully operated to detect neutrons with a measured efficiency of 11.8% at a wavelength of 2 angstrom and a position resolution better than 250 mu m.

Place, publisher, year, edition, pages
IOP PUBLISHING LTD, 2016
Keywords
Neutron detectors (cold, thermal, fast neutrons); Neutron diffraction detectors; Particle tracking detectors
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:liu:diva-130142 (URN)10.1088/1748-0221/11/05/P05011 (DOI)000377851700034 ()
Note

Funding Agencies|EU Horizon 2020 framework, BrightnESS project [676548]

Available from: 2016-07-12 Created: 2016-07-11 Last updated: 2017-11-28
Muraro, A., Albani, G., Perelli Cippo, E., Croci, G., Angella, G., Birch, J., . . . Tardocchi, M. (2016). Neutron radiography as a non-destructive method for diagnosing neutron converters for advanced thermal neutron detectors. Paper presented at International Workshop on Imaging. Journal of Instrumentation, 11(C03033)
Open this publication in new window or tab >>Neutron radiography as a non-destructive method for diagnosing neutron converters for advanced thermal neutron detectors
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2016 (English)In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, no C03033Article in journal (Refereed) Published
Abstract [en]

Due to the well-known problem of He-3 shortage, a series of different thermal neutron detectors alternative to helium tubes are being developed, with the goal to find valid candidates for detection systems for the future spallation neutron sources such as the European Spallation Source (ESS). A possible He-3-free detector candidate is a charged particle detector equipped with a three dimensional neutron converter cathode (3D-C). The 3D-C currently under development is composed by a series of alumina (Al2O3) lamellas coated by 1 mu m of B-10 enriched boron carbide (B4C). In order to obtain a good characterization in terms of detector efficiency and uniformity it is crucial to know the thickness, the uniformity and the atomic composition of the B4C neutron converter coating. In this work a non-destructive technique for the characterization of the lamellas that will compose the 3D-C was performed using neutron radiography. The results of these measurements show that the lamellas that will be used have coating uniformity suitable for detector applications. This technique (compared with SEM, EDX, ERDA, XPS) has the advantage of being global (i.e. non point-like) and non-destructive, thus it is suitable as a check method for mass production of the 3D-C elements.

Place, publisher, year, edition, pages
Institute of Physics (IOP), 2016
Keywords
Inspection with neutrons; Neutron radiography; Image filtering; Data processing methods
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-128972 (URN)10.1088/1748-0221/11/03/C03033 (DOI)000375746200034 ()
Conference
International Workshop on Imaging
Available from: 2016-06-09 Created: 2016-06-07 Last updated: 2017-08-28
Piscitelli, F., Khaplanov, A., Devishvili, A., Schmidt, S., Höglund, C., Birch, J., . . . Van Esch, P. (2016). Neutron reflectometry on highly absorbing films and its application to (B4C)-B-10-based neutron detectors. Proceedings of the Royal Society. Mathematical, Physical and Engineering Sciences, 472(2185), 20150711
Open this publication in new window or tab >>Neutron reflectometry on highly absorbing films and its application to (B4C)-B-10-based neutron detectors
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2016 (English)In: Proceedings of the Royal Society. Mathematical, Physical and Engineering Sciences, ISSN 1364-5021, E-ISSN 1471-2946, Vol. 472, no 2185, p. 20150711-Article in journal (Refereed) Published
Abstract [en]

Neutron reflectometry is a powerful tool used for studies of surfaces and interfaces. The absorption in the typical studied materials is neglected and this technique is limited only to the reflectivity measurement. For strongly absorbing nuclei, the absorption can be directly measured by using the neutron-induced fluorescence technique which exploits the prompt particle emission of absorbing isotopes. This technique is emerging from soft matter and biology where highly absorbing nuclei, in very small quantities, are used as a label for buried layers. Nowadays, the importance of absorbing layers is rapidly increasing, partially because of their application in neutron detection; a field that has become more active also due to the He-3-shortage. We extend the neutron-induced fluorescence technique to the study of layers of highly absorbing materials, in particular (B4C)-B-10. The theory of neutron reflectometry is a commonly studied topic; however, when a strong absorption is present the subtle relationship between the reflection and the absorption of neutrons is not widely known. The theory for a general stack of absorbing layers has been developed and compared to measurements. We also report on the requirements that a (B4C)-B-10 layer must fulfil in order to be employed as a converter in neutron detection.

Place, publisher, year, edition, pages
ROYAL SOC, 2016
Keywords
neutron-induced fluorescence; neutron reflectometry; boron-10; neutron detection
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-125159 (URN)10.1098/rspa.2015.0711 (DOI)000368479000021 ()
Note

Funding Agencies|BrightnESS project [INFRADEV-3-2015, 676548]; CRISP project (European Commission) [283745]; Swedish Research Council VR [2009-6232]; Carl Tryggers Foundation for Scientific Research; Knut and Alice Wallenberg Foundation

Available from: 2016-02-15 Created: 2016-02-15 Last updated: 2017-11-30
Bakoglidis, K., Nedelcu, I., Schmidt, S., Greczynski, G., Ehret, P. & Hultman, L. (2016). Rolling contact fatigue of bearing components coated with carbon nitride thin films. Tribology International, 98, 100-107
Open this publication in new window or tab >>Rolling contact fatigue of bearing components coated with carbon nitride thin films
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2016 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 98, p. 100-107Article in journal (Refereed) Published
Abstract [en]

Bearing rollers were coated with CNx films using high power impulse magnetron sputtering deposition in order to reduce their rolling-contact fatigue as investigated using a Micro-Pitting Rig tribometer under poly-alpha-olefin lubricated conditions. Coated rollers with a similar to 15 nm thick W adhesion layer to the substrate, exhibit the best performance, presenting mild wear and no fatigue after 700 kcycles. The steady-state friction coefficient was similar to 0.05 for both uncoated and coated rollers. Uncoated rollers show run-in friction in the first 50 kcycles, because of steel-to-steel contact, which is absent for coated rollers. Analytical transmission electron microscopy and X-ray photoelectron spectroscopy show that the presence of a CNx coating prevents steel-to-steel contact of the counterparts, prior to the elastohydrodynamic lubrication, reducing their wear and increasing the lifetime expectancy. (C) 2016 Elsevier Ltd. All rights reserved.

Place, publisher, year, edition, pages
ELSEVIER SCI LTD, 2016
Keywords
Coating; Pitting; Rolling; Lubrication
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-128933 (URN)10.1016/j.triboint.2016.02.017 (DOI)000374426000011 ()
Note

Funding Agencies|Carl Tryggers Foundation for Scientific Research [CTS 14:431]

Available from: 2016-06-09 Created: 2016-06-07 Last updated: 2017-11-30
Hänninen, T., Schmidt, S., Wissting, J., Jensen, J., Hultman, L. & Högberg, H. (2016). Stoichiometric silicon oxynitride thin films reactively sputtered in Ar/N2O plasmas by HiPIMS. Journal of Physics D: Applied Physics, 49(13), Article ID 135309.
Open this publication in new window or tab >>Stoichiometric silicon oxynitride thin films reactively sputtered in Ar/N2O plasmas by HiPIMS
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2016 (English)In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 49, no 13, article id 135309Article in journal (Refereed) Published
Abstract [en]

Silicon oxynitride (SiOxNy, x = 0.2 − 1.3, y = 0.2 − 0.7) thin films were synthesized by reactive high power impulse magnetron sputtering from a pure silicon target in Ar/N2O atmospheres. It is found that the composition of the material can be controlled by the reactive gas flow and the average target power. X-ray photoelectron spectroscopy (XPS) shows that high average powers result in more silicon-rich films, while lower target powers yield silicon-oxide-like material due to more pronounced target poisoning. The amount of nitrogen in the films can be controlled by the percentage of nitrous oxide in the working gas. The nitrogen content remains at a constant level while the target is operated in the transition region between metallic and poisoned target surface conditions. The extent of target poisoning is gauged by the changes in peak target current under the different deposition conditions. XPS also shows that varying concentrations and ratios of oxygen and nitrogen in the films result in film chemical bonding structures ranging from silicon-rich to stoichiometric silicon oxynitrides having no observable Si−Si bond contributions. Spectroscopic ellipsometry shows that the film optical properties depend on the amount and ratio of oxygen and nitrogen in the compound, with film refractive indices measured at 633 nm ranging between those of SiO2 and Si3N4.

Place, publisher, year, edition, pages
Institute of Physics (IOP), 2016
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-123382 (URN)10.1088/0022-3727/49/13/135309 (DOI)000371908800023 ()
Note

Funding agencies:  Carl Tryggers Foundation for Scientific Research; European Union under the LifeLongJoints Project [GA-310477]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]

Available from: 2015-12-15 Created: 2015-12-15 Last updated: 2018-02-13Bibliographically 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
Hänninen, T., Schmidt, S., Jensen, J., Hultman, L. & Högberg, H. (2015). Silicon oxynitride films deposited by reactive high power impulse magnetron sputtering using nitrous oxide as a single-source precursor. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, 33(5), 05E121
Open this publication in new window or tab >>Silicon oxynitride films deposited by reactive high power impulse magnetron sputtering using nitrous oxide as a single-source precursor
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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, p. 05E121-Article in journal (Refereed) Published
Abstract [en]

Silicon oxynitride thin films were synthesized by reactive high power impulse magnetron sputtering of silicon in argon/nitrous oxide plasmas. Nitrous oxide was employed as a single-source precursor supplying oxygen and nitrogen for the film growth. The films were characterized by elastic recoil detection analysis, x-ray photoelectron spectroscopy, x-ray diffraction, x-ray reflectivity, scanning electron microscopy, and spectroscopic ellipsometry. Results show that the films are silicon rich, amorphous, and exhibit a random chemical bonding structure. The optical properties with the refractive index and the extinction coefficient correlate with the film elemental composition, showing decreasing values with increasing film oxygen and nitrogen content. The total percentage of oxygen and nitrogen in the films is controlled by adjusting the gas flow ratio in the deposition processes. Furthermore, it is shown that the film oxygen-to-nitrogen ratio can be tailored by the high power impulse magnetron sputtering-specific parameters pulse frequency and energy per pulse. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

Place, publisher, year, edition, pages
A V S AMER INST PHYSICS, 2015
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-121906 (URN)10.1116/1.4927493 (DOI)000361229000021 ()
Note

Funding Agencies|European Union [GA-310477]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]

Available from: 2015-10-13 Created: 2015-10-12 Last updated: 2018-02-13
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