Article
Chemistry, Physical
N. A. Richter, B. Yang, J. P. Barnard, T. Niu, X. Sheng, D. Shaw, M. Watanabe, G. Rane, U. Krause, P. Duerrenfeld, H. Wang, X. Zhang
Summary: In this study, the influence of bipolar pulsed direct current (DC) magnetron sputtering on the microstructure evolution of titanium nitride (TiN) coatings is explored and compared with conventional DC sputtering. The implementation of pulsed DC voltage promotes a drastic texture change from randomly oriented polycrystals to (111) textured TiN coatings across various Si substrates, including amorphous SiO2. Higher pulse frequencies contribute to significant grain size reduction, resulting in increased hardness and wear resistance. The potential mechanism for this microstructural and texture evolution is also investigated.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Rafal Chodun, Marlena Dypa, Bartosz Wicher, Katarzyna Nowakowska - Langier, Sebastian Okrasa, Roman Minikayev, Krzysztof Zdunek
Summary: This study investigated a Gas Injection Magnetron Sputtering technique for target temperature control by using various frequencies of plasma pulse generation to limit heat dissipation. The results showed that target temperature did not affect the chemical and phase composition of coatings, but the thickness of fabricated coatings increased in hot sputtering processes.
APPLIED SURFACE SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Samira Dorri, Justinas Palisaitis, Grzegorz Greczynski, Ivan Petrov, Jens Birch, Lars Hultman, Babak Bakhit
Summary: We studied the oxidation properties of sputter-deposited TiB2.5 coatings at different temperatures. The results showed that at 600 degrees Celsius, the coating exhibited protective oxidation behavior, and the structure of the oxide layer also changed. Moreover, decreasing the heating rate had a noticeable impact on the oxidation process.
Article
Chemistry, Multidisciplinary
Grzegorz Wisz, Paulina Sawicka-Chudy, Maciej Sibinski, Dariusz Ploch, Mariusz Bester, Marian Cholewa, Janusz Wozny, Rostyslav Yavorskyi, Lyubomyr Nykyruy, Marta Ruszala
Summary: In this study, titanium dioxide/copper oxide thin-film solar cells were prepared using the reactive direct-current magnetron sputtering technique. The influence of the deposition time of the top Cu contact layer on the structural and electrical properties of photovoltaic devices was analyzed. The structural and morphological characterization of the TiO2/CuO/Cu2O solar cells was fully studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and current-voltage (I-V) characteristics.
Article
Materials Science, Multidisciplinary
Claudia P. Mejia, Henry S. Vanegas, Jhon J. Olaya
Summary: The formation of nanostructured transition metal nitride coatings by introducing a small amount of silver has been proven to enhance the physical properties of these materials. This investigation studied the influence of silver on the chemical composition, morphology, and microstructure of ZrN coatings, as well as their functional properties including corrosion resistance and optical reflectance. The results showed that the incorporation of silver improved the corrosion resistance and increased the optical reflectance of the coatings, making them potentially useful as optical protective coatings.
Article
Chemistry, Physical
Igor O. Akimchenko, Sven Rutkowski, Tuan-Hoang Tran, Gleb E. Dubinenko, Vsevolod Petrov, Anna Kozelskaya, Sergei Tverdokhlebov
Summary: Polyether ether ketone has gained increasing interest as an alternative material for bone implants. However, its bioinert and hydrophobic surface lead to poor cell adhesion and slow integration with bone tissue. This study modified the surface of polyether ether ketone implants by depositing ultrathin titanium and zirconium coatings, which improved biocompatibility and cell adhesion without changing the substrate's crystalline structure.
Article
Chemistry, Physical
Siddharth Sharma, Ravikant Adalati, Nitesh Choudhary, B. S. Unnikrishnan, Meenakshi Sharma, P. Gopinath, Ramesh Chandra
Summary: In this study, a flexible and biocompatible supercapacitor device was successfully fabricated using NbN and TiN electrodes directly deposited on SS through magnetron sputtering. The device exhibited efficient electrochemical stability, high capacitive performance, and excellent cyclic stability in physiological fluid. Furthermore, cell viability studies confirmed the in-vitro biocompatibility of the electrodes, making it a potential candidate for powering medical and implantable electronic devices.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Luca Mascaretti, Tapan Barman, Beatrice Roberta Bricchi, Filip Munz, Andrea Li Bassi, Stepan Kment, Alberto Naldoni
Summary: Magnetron sputtering is crucial in producing TiN thin films, impacting their structural, optical, and electrical properties. RF substrate biasing during sputtering process can optimize the plasmonic effects and resistivity of TiN films by introducing a slight under-stoichiometry in the material.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Coatings & Films
Niklas Hellgren, Alexander Sredenschek, Andrejs Petruins, Justinas Palisaitis, Fedor F. Klimashin, Maurico A. Sortica, Lars Hultman, Per O. A. Persson, Johanna Rosen
Summary: Titanium boride thin films with varying B/Ti ratio were successfully grown using DC magnetron co-sputtering. The films exhibited high hardness and low resistivity, with different grain sizes and crystalline characteristics after annealing.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Ebrahim Abualgassem, Monzer Maarouf, Abdulhakim Bake, David Cortie, Khan Alam, Muhammad Baseer Haider
Summary: This study investigates the properties of cobalt-doped titanium nitride thin films grown by reactive co-sputtering. The films readily oxidize after exposure to the atmosphere and form cobalt-doped titanium oxynitride. The variable cobalt concentration in the films affects their optical, chemical, and magnetic properties. At higher cobalt concentrations, the films have a narrower bandgap and exhibit a temperature-dependent magnetic response with a mix of paramagnetism and superparamagnetism.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Multidisciplinary Sciences
Ihwanul Aziz, Emy Mulyani, Yusril Yusuf
Summary: The study coated Stainless Steel 316 L (SS 316 L) orthopedic implants with copper-doped Titanium Nitride (Ti-Cu-N) using the DC Sputtering technique, which improved their antibacterial performance and mechanical properties. The results showed that samples with 44.34 wt% and 54.97 wt% copper had antibacterial effectiveness against Staphylococcus aureus (S. Aureus).
Article
Crystallography
He Gao, Shijian Wang, Da Xu, Xueshen Wang, Qing Zhong, Yuan Zhong, Jinjin Li, Wenhui Cao
Summary: In this study, a comprehensive analysis was conducted on the properties of DC magnetron sputtered Nb films fabricated with constant power at the National Institute of Metrology (China). The results showed that the stress and other parameters of the films can maintain a relatively stable state under constant power and Ar pressure.
Article
Materials Science, Multidisciplinary
Vladimir R. Shayapov, Alena L. Bogoslovtseva, Sergey Yu. Chepkasov, Igor P. Asanov, Evgeny A. Maksimovskiy, Aleksandr V. Kapishnikov, Maria I. Mironova, Alina V. Lapega, Pavel V. Geydt
Summary: The chemical composition, structure, and physical properties of aluminum nitride (AlN) films obtained by pulsed DC reactive magnetron sputtering in asymmetric bipolar mode were studied. X-ray diffraction and electron diffraction confirmed the required composition of c-axis textured hexagonal AlN films for piezoelectric applications. The films obtained had a smooth surface with an arithmetic average roughness of less than 2 nm. Transmission electron microscopy revealed the presence of a transition layer at the film-substrate interface. Despite an oxidized surface layer, the films' piezoresponse remained unaffected.
Article
Materials Science, Multidisciplinary
Daoming You, Yu Jiang, Yali Zhao, Wentao Guo, Manqing Tan
Summary: Silicon nitride films were deposited by ion-assisted pulsed DC reactive magnetron sputtering, and the regulation of power was found to affect the refractive index. By adjusting the ion source and target powers, the refractive index range was extended, and low extinction coefficients were obtained. The composition of the films varied with power, covering nitride-rich to silicon-rich. This study proposed a method for depositing silicon nitride films with a widely tunable refractive index range, which has potential applications in optical thin films and waveguides.
Article
Materials Science, Multidisciplinary
Telmo Eleuterio, Susana Serio, Helena C. Vasconcelos
Summary: TiO2 thin films were deposited on ginger lily fibers using a DC reactive magnetron sputtering system, and the effects of deposition conditions on the structure and surface morphology of the films were investigated. XRD analysis revealed the presence of anatase and rutile phases depending on the oxygen percentage and sputtering power. SEM imaging showed that the films displayed different surface features, with porosity observed in films deposited with 50% O-2 and 1000 W. Adhesion tests indicated good adhesion for most films, with slightly lower adhesion observed in the porous film.
Article
Materials Science, Ceramics
M. A. Correa, A. Ferreira, S. A. N. Franca Jr, W. Acchar, M. Rodrigues, M. Gamino, F. Bohn, F. Vaz
Summary: GnP doped Al2O3 flexible tapes were produced through Tape Casting technique and used as substrates for Co2FeAl/GnP doped Al2O3 heterostructures. The Co2FeAl layers were grown using Magnetron Sputtering. The integration of both techniques allowed exploration of the thermomagnetic properties of the heterostructure through the Anomalous Nernst Effect, and the results showed isotropic magnetic behavior of the Co2FeAl films.
CERAMICS INTERNATIONAL
(2023)
Review
Food Science & Technology
Diana I. Meira, Ana I. Barbosa, Joel Borges, Rui L. Reis, Vitor M. Correlo, Filipe Vaz
Summary: Global population growth has a significant impact on the global food industry, posing a threat to food safety and quality. Mycotoxins, particularly Ochratoxin-A (OTA), are produced by fungus that contaminates various food species and products. OTA not only endangers food production but also poses potential toxicological risks to humans, leading to carcinogenic and neurological diseases. Therefore, the development of a selective, sensitive, and reliable OTA biodetection approach is crucial for ensuring food safety.
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION
(2023)
Article
Computer Science, Information Systems
Julio Barros, Francisco Cunha, Candido Martins, Paulo Pedrosa, Paulo Cortez
Summary: The emergence of Industry 4.0 and digital transformation have significantly improved supply chain performance and competitive advantage. This study focuses on enhancing the order fulfilment process and specifically the cement loading process by using machine learning to predict weighing deviations. The random forest model provides the best predictive performance, and the Shapley additive explanations method helps understand the influence of input data attributes.
Article
Multidisciplinary Sciences
Patrique Fiedler, Jens Haueisen, Ana M. Cebolla Alvarez, Guy Cheron, Pablo Cuesta, Fernando Maestu, Michael Funke
Summary: The cognitive performance of the crew is crucial for the safety and success of space flights. Monitoring cognitive performance during space missions is important and can be done using compact mobile EEG devices. However, the signal quality of EEG may be affected by nearby electronic devices and movements. This study compares the noise characteristics of EEG recordings in space and on the ground, and finds that in-flight recordings have significantly lower noise levels. Actively shielded mobile dry EEG systems can be used for neuroscientific research and cognitive monitoring during long-duration space missions.
Article
Chemistry, Analytical
Ricardo Spyrides Boabaid Pimentel Goncalves, Jens Haueisen
Summary: Three-dimensional scanning using rotation and immersion in a water-based fluid was developed as a low-cost alternative to traditional CT scanners. By utilizing a container filled with water and Xanthan gum, objects were submerged and scanned at various rotation angles. The results showed that this technique was feasible for producing reconstructed images of objects with irregular shapes or openings at a significantly lower cost.
Article
Nanoscience & Nanotechnology
Claiudia Lopes, Armando Ferreira, Marcio Correa, Andre Machado Rodrigues, Paulo Mendes, Filipe Vaz
Summary: This study investigates the potential of thin-film technology in the development of new electromagnetic interference shielding and conductive materials for textiles and wearables. The study used three different thin films (pure Ti, pure Cu, and Ti-doped Cu) to enhance textile knits made of cotton and lyocell fibers. The films exhibited varying structures, morphologies, and topographies based on their chemical compositions. The effectiveness of these functionalized knits in shielding against EMI was evaluated, as well as their electrical response under stress.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Ceramics
S. A. N. Franca Junior, W. Acchar, S. L. A. Dantas, P. H. Chiberio, H. P. A. Alves, M. R. D. Bomio, F. V. Motta, F. Bohn, A. Ferreira, F. Vaz, M. A. Correa
Summary: We conducted a comprehensive investigation on the high-frequency dielectric properties of (ZrO2)100-x(BaTiO3)x heterostructures. By adjusting the content of BaTiO3, we could modify the dielectric constant of the resulting ceramic sheets. Our results demonstrated successful fabrication of heterostructured ceramic sheets and the ability to tailor the electric, structural, and dielectric properties of both ZrO2 and BaTiO3 materials. Furthermore, the evolution of the dielectric constant could be manipulated according to specific technological applications.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Armando Ferreira, Carlos M. Costa, Marcio A. Correa, Rafael S. Pinto, Renato Gonsalves, Luana C. Benetti, Senentxu Lanceros-Mendez, Filipe Vaz
Summary: The necessity for energy conversion solutions has increased in recent years, particularly for powering small and flexible IoT devices. This study explores the use of thermoelectric effects, specifically the anomalous Nernst effect, by producing Co2FeAl/P(VDF-TrFE-CFE) heterostructures on flexible poly (vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) substrates. The results demonstrate that the flexible polymer substrate does not affect the thermomagnetic effect, opening new possibilities for integrating flexible high-dielectric polymers with thermomagnetic phenomena for energy harvesting applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Claudia Lopes, Marco S. Rodrigues, Armando Ferreira, Francisco Macedo, Ioana Borsan, Camelia Gabor, Mihai-Alin Pop, Eduardo Alves, Nuno P. Barradas, Daniel Munteanu, Filipe Vaz
Summary: This study investigated the impact of nanostructure design on the optical, electrical, and thermal properties of titanium nitride (TiNx) thin films. Results showed that modifying the nanostructure design rather than changing the composition can alter the properties of thin films. Thin films prepared by GLancing Angle Deposition (GLAD) exhibited wider and more significant variations in optical and electrical properties, while thermal properties were more affected by structural changes induced by the N content in the films. GLAD geometries resulted in a reduction in film reflectivity and color coordinates, as well as an increase in electrical resistivity. The thermal parameters of effusivity ratio and diffusivity decreased with an increase in the N/Ti ratio.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Instruments & Instrumentation
A. Ribeiro, M. Proenca, N. Catarino, M. Dias, M. Peres, J. Borges, F. Vaz, E. Alves
Summary: This paper investigates the formation of Au-nanoparticles (AuNPs) in titanium dioxide (TiO2) through ion implantation. TiO2 thin films were deposited on glass and silicon using magnetron sputtering. AuNPs were created by ion implantation with fluences ranging from 2.0 x 1016 to 4.0 x 1017 ions/cm2. Post-implantation thermal treatment at 500°C was applied to promote precipitation of the implanted Au. Rutherford backscattering spectrometry and X-ray diffraction analysis were used to analyze the elemental depth profiles and confirm the presence of AuNPs.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2023)
Article
Chemistry, Analytical
Daniel Carvalho, Sandra Marques, Giorgia Siqueira, Armando Ferreira, Joao Santos, Dulce Geraldo, Cidalia R. Castro, Ana V. Machado, Filipe Vaz, Claudia Lopes
Summary: This study evaluates the lifespan of Ti-Ag dry electrodes prepared using flexible polytetrafluoroethylene (PTFE) substrates. The research finds that higher Ag content results in increased corrosion and reduced lifespan of the electrodes. The long-term performance of electrodes is critical for reliable and sustained monitoring and stimulation in remote biomedical applications like smart wearables.
Proceedings Paper
Computer Science, Artificial Intelligence
R. Conselheiro, C. Lopes, N. Azevedo, P. Leitao, C. Agulhari, H. Veloso, F. Vaz, J. Goncalves, T. Franco, L. Sestrem
Summary: Wet electrodes, which rely on conductive electrolyte gel, have issues such as long setup time, disposability or time-consuming cleaning, skin irritation, and signal quality deterioration. To overcome these drawbacks, 3D printed bases with polymers and functionalized with thin films of titanium and titanium-nitride, doped with copper, were developed. The results show that these dry electrodes have similar performance to wet AgCl/Ag electrodes for data acquisition, but improvements are needed for muscle stimulation and the durability and adhesion of the thin films.
19TH INTERNATIONAL SYMPOSIUM ON DISTRIBUTED COMPUTING AND ARTIFICIAL INTELLIGENCE
(2023)
Article
Chemistry, Physical
Diogo Costa, Marco S. Rodrigues, Eduardo Alves, Nuno P. Barradas, Joel Borges, Filipe Vaz
Summary: This work describes the development of nanoplasmonic thin films with Au, Ag, or Au-Ag nanoparticles dispersed in a TiO2 matrix, and the optimization of deposition parameters to adjust their optical response. The study found that using Au-Ag nanoparticles can increase the refractive index sensitivity of the thin films and reduce the cost of fabrication.
Article
Chemistry, Analytical
Diana I. Meira, Marco S. Rodrigues, Joel Borges, Filipe Vaz
Summary: The extinction efficiency of noble metal nanoparticles, such as gold and silver, depends on their size and the dielectric surrounding them. By exploiting the Localized Surface Plasmon Resonance (LSPR) phenomenon, the composition and structure of these nanoparticles can be tailored to optimize their sensitivity to environmental changes. Incorporating these nanoparticles into solid support in the form of nanocomposite thin films enhances the robustness of LSPR sensing. In this study, bimetallic films composed of gold, silver, and their mixture in a titanium dioxide matrix were grown using reactive DC magnetron sputtering. The LSPR response and sensitivity of the films were tunable by thermal treatment at different temperatures. The bimetallic film with an Au/Ag atomic ratio of 1 exhibited the highest refractive index sensitivity, showcasing the potential of bimetallic film systems in enhancing LSPR sensing.
Article
Engineering, Electrical & Electronic
Giorgia Siqueira, David Baptista, Claudia Lopes, Marcio A. Correa, Filipe Vaz, Armando Ferreira
Summary: This study explores the influence of non-magnetic cap layer thickness on the thermoelectric properties of Co2FeAl/NM heterostructures and analyzes their potential applications in the Anomalous Nernst Effect and Longitudinal Spin Seebeck Effect. The experimental results demonstrate that Co2FeAl/W and Co2FeAl/Ti heterostructures exhibit enhanced ANE voltages, providing valuable insights into Co2FeAl-based materials and spintronic devices.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
