Microstructures of magnetron sputtered Fe–Au thin films

Zamponi, Christiane; Schürmann, Ulrich; Jurgeleit, Till; Kienle, Lorenz; Quandt, Eckhard

doi:10.3139/146.111159

Cited by 6 publications

(8 citation statements)

References 30 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, different fabrication or metal processing techniques were investigated, such as electroforming (E-Fe) [ 6 , 7 ], magnetron sputtering (S-Fe) [ 8 ], rolling techniques [ 9 , 10 ], and equal channel angular pressing (ECAP-Fe) [ 11 , 12 , 13 ]. Also, the influence of implementing precipitates, namely Pd [ 14 , 15 , 16 , 17 ], Au [ 18 , 19 , 20 , 21 ], Pt [ 17 ], Fe 2 O 3 particles [ 22 ], and carbon nanotubes [ 23 ] into the Fe matrix was studied. To enhance the material properties with respect to the requirements, the addition of different alloying elements such as Mn, Co, Al, W, Sn, B, C, and S was investigated [ 24 ].…”

Section: Introductionmentioning

confidence: 99%

Magnetron Sputtering as a Fabrication Method for a Biodegradable Fe32Mn Alloy

2017

Self Cite

View full text Add to dashboard Cite

Biodegradable metals are a topic of great interest and Fe-based materials are prominent examples. The research task is to find a suitable compromise between mechanical, corrosion, and magnetic properties. For this purpose, investigations regarding alternative fabrication processes are important. In the present study, magnetron sputtering technology in combination with UV-lithography was used in order to fabricate freestanding, microstructured Fe32Mn films. To adjust the microstructure and crystalline phase composition with respect to the requirements, the foils were post-deposition annealed under a reducing atmosphere. The microstructure and crystalline phase composition were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. Furthermore, for mechanical characterization, uniaxial tensile tests were performed. The in vitro corrosion rates were determined by electrochemical polarization measurements in pseudo-physiological solution. Additionally, the magnetic properties were measured via vibrating sample magnetometry. The foils showed a fine-grained structure and a tensile strength of 712 MPa, which is approximately a factor of two higher compared to the sputtered pure Fe reference material. The yield strength was observed to be even higher than values reported in literature for alloys with similar composition. Against expectations, the corrosion rates were found to be lower in comparison to pure Fe. Since the annealed foils exist in the austenitic, and antiferromagnetic γ-phase, an additional advantage of the FeMn foils is the low magnetic saturation polarization of 0.003 T, compared to Fe with 1.978 T. This value is even lower compared to the SS 316L steel acting as a gold standard for implants, and thus enhances the MRI compatibility of the material. The study demonstrates that magnetron sputtering in combination with UV-lithography is a new concept for the fabrication of already in situ geometrically structured FeMn-based foils with promising mechanical and magnetic properties.

show abstract

Section: Introductionmentioning

confidence: 99%

Magnetron Sputtering as a Fabrication Method for a Biodegradable Fe32Mn Alloy

2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…No stable compounds are known for this system [30], and no oxidation is expected for such alloys [31], so that Au atoms are either in the bulk of Fe grains or along their grain boundaries. Segregation of Au at grain boundaries is well documented in α-Fe [32,33], and even though the FCC structure of γ-Fe differs by its coordination number and grain boundary structure, the main predictor for segregation -a large mismatch in atomic size [34,35] -remains unchanged. Indeed, our estimations of ΔH seg revealed similar values between the phases (see Supplementary Materials [24]).…”

Section: Main Textmentioning

confidence: 99%

Higher Temperatures Yield Smaller Grains in a Thermally Stable Phase-Transforming Nanocrystalline Alloy

Amram

Schuh

2018

Phys. Rev. Lett.

View full text Add to dashboard Cite

Grains in crystalline materials usually grow with increased thermal exposure. Classical phenomena such as recrystallization may lead to a purely temporary decrease in the grain size, while recent advances in alloy design can yield thermally stable nanocrystalline materials in which grain growth stagnates. But grains never shrink, since there is a lack of interfacegenerating mechanisms at high temperatures, which are required to decrease the grain size if such was the system's thermodynamic tendency. Here we sidestep this paradigm by designing a nanocrystalline alloy having an allotropic phase transformation-an interface-generating mechanism-such that only the high-temperature phase is stabilized against grain growth. We demonstrate that for an Fe-Au alloy cycled through the α↔γ transformation, the hightemperature phase (γ-Fe) has a stable fine grain size, smaller than its low-temperature counterpart (α-Fe). The result is an unusual material in which an increase in temperature leads to finer grains that are stable in size.

show abstract

“…In previous works of the authors, it was shown that magnetron sputtering is a feasible method for fabricating freestanding micro-patterned devices for degradable implants. A high strength was observed, due to the unique microstructure achieved by this technique [ 12 , 13 , 14 , 15 ]. The usage of magnetron sputtering in combination of UV lithography for the fabrication of NiTi devices for medical applications was first shown by Zamponi, Siekmeyer, and de Miranda et al [ 16 , 17 , 18 , 19 ].…”

Section: Introductionmentioning

confidence: 99%

Magnetron-Sputtered, Biodegradable FeMn Foils: The Influence of Manganese Content on Microstructure, Mechanical, Corrosion, and Magnetic Properties

et al. 2018

Self Cite

View full text Add to dashboard Cite

FeMn alloys show a great potential for the use as a biodegradable material for medical vascular implants. To optimize the material properties, with respect to the intended application, new fabrication methods also have to be investigated. In this work different Fe–FeMn32 multilayer films were deposited by magnetron sputtering. The deposition was done on a substrate structured by UV lithography. This technique allows the fabrication of in-situ structured foils. In order to investigate the influence of the Mn content on the material properties foils with an overall Mn content of 5, 10, 15, and 17 wt % were fabricated. The freestanding foils were annealed post-deposition, in order to homogenize them and adjust the material properties. The material was characterized in terms of microstructure, corrosion, mechanical, and magnetic properties using X-ray diffraction, electron microscopy, electrochemical polarization, immersion tests, uniaxial tensile tests, and vibrating sample magnetometry. Due to the unique microstructure that can be achieved by the fabrication via magnetron sputtering, the annealed foils showed a high mechanical yield strength (686–926 MPa) and tensile strength (712–1147 MPa). Owing the stabilization of the non-ferromagnetic ε- and γ-phase, it was shown that even Mn concentrations of 15–17 wt % are sufficient to distinctly enhance the magnetic resonance imaging (MRI) compatibility of FeMn alloys.

show abstract

Microstructures of magnetron sputtered Fe–Au thin films

Cited by 6 publications

References 30 publications

Magnetron Sputtering as a Fabrication Method for a Biodegradable Fe32Mn Alloy

Magnetron Sputtering as a Fabrication Method for a Biodegradable Fe32Mn Alloy

Higher Temperatures Yield Smaller Grains in a Thermally Stable Phase-Transforming Nanocrystalline Alloy

Magnetron-Sputtered, Biodegradable FeMn Foils: The Influence of Manganese Content on Microstructure, Mechanical, Corrosion, and Magnetic Properties

Contact Info

Product

Resources

About