Article
Chemistry, Physical
Yongjian Luo, Zhenxun Tang, Xiaozhe Yin, Chao Chen, Zhen Fan, Minghui Qin, Min Zeng, Guofu Zhou, Xingsen Gao, Xubing Lu, Jiyan Dai, Deyang Chen, Jun -Ming Liu
Summary: This study demonstrates that ferroelectric properties can be observed in non-capped dopant-free HfO2 thin films by adjusting the deposition temperature, oxygen pressure, and thickness. A maximum polarization strength of 14.7 mu C/cm(2) was achieved in a 7.4 nm-thick film, suggesting a new method for fabricating high-quality ferroelectric HfO2 thin films.
JOURNAL OF MATERIOMICS
(2022)
Article
Chemistry, Physical
Nicole Bartek, Vladimir V. Shvartsman, Houssny Bouyanfif, Alexander Schmitz, Gerd Bacher, Selina Olthof, Svetlana Sirotinskaya, Niels Benson, Doru C. Lupascu
Summary: Ferroelectric materials have attracted attention for photovoltaic applications, with lead-based ferroelectric perovskite thin films and PbFe0.5Nb0.5O3 (PFN) being studied. PFN has a relatively low band gap value, which can enhance its light absorption capability, making it a promising candidate as an absorber material.
Article
Materials Science, Multidisciplinary
Shijia Cheng, Qing Chang, Zeng Wang, Lian Xiao, Elbert E. M. Chia, Handong Sun
Summary: This study demonstrates the fabrication of high crystalline and coverage CsPbBr3 thin films using a single-step physical technique - pulsed laser deposition (PLD), showing stimulated emission with low pump threshold at room temperature, providing insights for high performance all-inorganic CsPbBr3 perovskite films in various optoelectronic devices.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
B. M. Silva, J. Oliveira, T. Rebelo, V. B. Isfahani, P. Rocha-Rodrigues, N. Lekshmi, J. H. Belo, F. L. Deepak, A. M. L. Lopes, J. P. Araujo, B. G. Almeida
Summary: Multiferroic Ruddlesden-Popper Ca3Mn2O7 thin films were prepared on SrTiO3 substrates by laser ablation. The films exhibited a ferroelectric phase and an orthorhombic phase, with substrate-induced strain enhancing the multiferroicity. The presence of magnetoelectric interactions and magnetically induced enhancement of dipolar correlations were observed.
MATERIALS RESEARCH BULLETIN
(2023)
Article
Materials Science, Multidisciplinary
Kumarswamy Miriyala, Adityanarayan H. Pandey, N. Shara Sowmya, Ajit R. Kulkarni, Venkataramani Narayanan
Summary: In this study, we investigate the structure and properties of the polycrystalline trilayer PNNZT/CTFO/PNNZT composite thin films grown on a substrate using a pulsed laser deposition technique. The individual ferroelectric PNNZT and ferromagnetic CTFO thin films display good functional properties, and the trilayer composite thin films also show significant ferroelectric and magnetic properties. Furthermore, these thin films exhibit a strong magnetoelectric coupling and have potential for device applications.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Tao Liu, Helei Dong, Hanyu Wang, Yanyan Niu, Xiangpeng Li, Lei Zhang, Jijun Xiong, Qiulin Tan
Summary: In this study, Pt-ITO thin-film thermocouples were fabricated using pulsed laser deposition on alumina ceramic substrates, and the microstructure and electrical properties were investigated. The results showed that the ITO thin films had a new type of nano cone structure, with a resistivity of only 2.76 x 10-4 omega center dot cm at a substrate temperature of 600 degrees C. The Pt-ITO thin-film thermocouples could work stably in the temperature range of 25-1300 degrees C and for a short time at 1400 degrees C. The average Seebeck coefficient was more than 50 mu V/degrees C at 1300 degrees C, and the response time was less than 435 mu s. These findings provide important insights for the potential application of Pt-ITO TFTCs in high-temperature measurement, and confirm the feasibility of preparing superior thermoelectric semiconductor materials using pulsed laser deposition.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Lubomir Prokes, Magdalena Gorylova, Katerina Cermak Sraitrova, Virginie Nazabal, Josef Havel, Petr Nemec
Summary: Pulsed UV laser deposition was used to prepare thin films of Sn50-xAsxSe50 to investigate the influence of low arsenic concentration on the properties of the deposited layers. Thin films containing 0.5 atom % of As exhibited extreme values that significantly differed from those of other samples. Signals of SnmSen+ clusters with low m and n values were observed in the mass spectra of both parent powders and deposited thin films.
Article
Chemistry, Physical
Kamlesh V. Chandekar, S. P. Yadav
Summary: The phase analysis and average crystallite size of MFe2O4 (M=Co, Ni, Zn) nano-particles were analyzed using X-ray diffraction (XRD) patterns. The morphology of MFe2O4 (M=Co, Ni, Zn) was observed through High-Resolution Transmission electron microscopy (HRTEM). The magnetic properties of the prepared MFe2O4 (M=Co, Ni, Zn) nanostructures were studied using M-H analysis, Zero field-cooled (ZFC) and field-cooled (FC) spectra, and EPR spectroscopy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Electrochemistry
Andrea Macrelli, Marco Olivieri, Alessio Lamperti, Valeria Russo, Benedetto Bozzini, Marco Menegazzo, Gianlorenzo Bussetti, Carlo S. Casari, Andrea Li Bassi
Summary: In this study, nanostructured ZnMn2O4 thin films were synthesized using pulsed laser deposition (PLD), and the effects of deposition and annealing conditions on the film properties were evaluated using various characterization techniques. The study revealed the modulation of film porosity by oxygen pressure and the combined effect of deposition pressure and annealing temperature on tailored properties of the film. The influence of film porosity on the voltammetric behavior of the film at higher scan rate was also highlighted. The research confirmed the complex electrochemical mechanism of ZnMn2O4 material and paved the way for nanoscale design of engineered ZnMn2O4-based electrodes.
ELECTROCHIMICA ACTA
(2023)
Article
Chemistry, Physical
Stefan Andrei Irimiciuc, Sergii Chertopalov, Maksym Buryi, Zdenek Remes, Martin Vondracek, Ladislav Fekete, Michal Novotny, Jan Lancok
Summary: CuI thin films were deposited with controlled morphology, structure, and defect nature in different Ar atmospheres. Band gap tailoring was achieved by controlling the plasma ion kinetic energy. Variation in Ar pressure allowed control over the nature of vacancies. Addition of Ar resulted in preferential scattering and energy losses of Cu ions in the plasma.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Rovena Veronica Pascu, George Epurescu, Iulian Boerasu, Ana -Maria Banici Niculescu, Dumitru Manica, Alexandra Maria Isabel Trefilov, Bogdan Alexandru Sava
Summary: Samarium doped ceria thin films were successfully deposited on Si (100) substrates at 500 and 600 degrees C using Pulsed Laser Deposition. X-ray Diffraction confirmed the presence of Samarium Doped Cerium Oxide crystalline compound in the films. Atomic Force Microscopy and Scanning Electron Microscopy revealed high quality films with low roughness, especially for the sample deposited at 600 degrees C. X-ray Photoelectron Spectroscopy showed an increased proportion of Ce3+ in the deposited films compared to the target. Spectroscopic Ellipsometry analysis calculated a refractive index under 2.2 in the visible and near-infrared domain. Nanoindentation tribometric measurements indicated a decrease in elasticity modulus and hardness with increasing substrate temperature. These films show potential as electrolyte materials for new generation electrochemical devices.
APPLIED SURFACE SCIENCE
(2022)
Article
Physics, Condensed Matter
Marianna Batkova, F. Stobiecki, B. Szymanski, P. Kuswik
Summary: Thin films of SmB6 were prepared using pulsed laser deposition on various substrates, showing that post-deposition annealing at 600 degrees C can result in high-quality material. However, heating the substrate during deposition leads to higher resistance. The electrical resistance measurements revealed that the resistivity can be described by a two-channel model with activation energy and impurity band effects.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Materials Science, Coatings & Films
Falko Jahn, Steffen Weissmantel
Summary: Boron carbide is a super-hard material suitable for wear resistant coatings. Its hardness is significantly influenced by substrate temperature, with little effect from laser fluence.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Chemistry, Physical
Xiangnan Gong, Menglei Feng, Hong Wu, Hongpeng Zhou, Chunhung Suen, Hanjun Zou, Lijie Guo, Kai Zhou, Shijian Chen, Jiyan Dai, Guoyu Wang, Xiaoyuan Zhou
Summary: This work focuses on improving the quality of highly (100)-oriented SnSe thin films for thermoelectric applications. By controlling key parameters during pulsed-laser deposition and performing vacuum thermal annealing, the film quality was enhanced. The best crystal quality and uniform orientation were achieved on SiO2/Si substrate at 673 K followed by thermal annealing at 673 K for 30 min, showcasing promising Seebeck coefficient and power factor values.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Ahmed S. Ahmed, Mohammed A. Hameed
Summary: The study showed that the doping of aluminum in cadmium oxide films affects the crystal structure and optical absorption properties, leading to a decrease in grain size, changes in growth planes, and an enlargement of the band gap.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Energy & Fuels
Morten Weiss, Gerald Hoerner, Birgit Weber, Roland Marschall
Summary: Tungsten-based defect-pyrochlores CsMxW2-xO6 are used as model oxides to investigate the high number of possible M cations that can be used to form the defect-pyrochlore crystal structure. A large variety of possible compounds are presented, several of which have been unknown so far. These compounds are used in photocatalytic hydrogen evolution to investigate possible correlations between the photocatalytic activity and the varying elemental compositions.
Article
Chemistry, Multidisciplinary
Erdogan Celik, Pascal Cop, Rajendra S. Negi, Andrey Mazilkin, Yanjiao Ma, Philip Klement, Joerg Schoermann, Sangam Chatterjee, Torsten Brezesinski, Matthias T. Elm
Summary: This study investigates the design of mixed-conducting nanocomposites by surface modification using atomic layer deposition (ALD). It was found that the porosity of the nanocomposites has no effect on their charge-transport properties, while the thickness of the ceria layer plays an important role.
Article
Chemistry, Multidisciplinary
Hannah Kurz, Christian Hils, Jana Timm, Gerald Hoerner, Andreas Greiner, Roland Marschall, Holger Schmalz, Birgit Weber
Summary: Responsive fluorescent materials have great potential for sensing and imaging applications. In this study, a previously reported non-fluorescent zinc(II) complex [Zn(L)] was encapsulated into non-fluorescent polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) diblock copolymer micelles, resulting in brightly emissive materials. The quantum yield of the emission could be easily tuned by selecting the solvent, and a medium-dependent off-on sensor could be established through controlled acidification.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Engineering, Chemical
Jana Timm, Roland Marschall
Summary: In this study, a novel gas phase functionalization method was used to achieve selective functionalization on hierarchical porous materials, which is crucial for various applications. Mesopores can be successfully functionalized, while micropores remain selectively non-functionalized after oxidation.
CHEMIE INGENIEUR TECHNIK
(2022)
Article
Chemistry, Physical
Julian Zahnow, Michele Bastianello, Juergen Janek, Matthias T. Elm
Summary: In this study, the electrochemical transport processes of individual grains with and without a grain boundary in microcrystalline oxide thin films were characterized using a microelectrode approach. It was found that the conductivity of single grains increases with increasing oxygen partial pressure, while the conductivity of grains with a grain boundary remains constant. These results are important for understanding the contribution of grain boundaries and grain interiors to the conductivity of polycrystalline materials.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Mario F. Zscherp, Michele Bastianello, Silvia Nappini, Elena Magnano, Denis Badocco, Silvia Gross, Matthias T. Elm
Summary: Metal spinel ferrites play important roles in magnetic, electrical and (photo-)catalytic device applications. The electrical conductivity of these ferrites can be controlled by tailoring their composition, degree of inversion, and non-stoichiometry. The substitution of Co for Zn in ZnFe2O4 ferrites significantly affects the activation energy and the type of hopping mechanism, depending on the atmospheric conditions. Our findings emphasize the importance of controlling non-stoichiometry for tuning the electrical properties of quaternary ferrites.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Julius K. Dinter, Jurek Lange, Detlev M. Hofmann, J. Fabian Plaza Fernandez, Angel Post, Sangam Chatterjee, Matthias T. Elm, Peter J. Klar
Summary: Mayenite [Ca24Al28O64](4+)(2O(2-)) is a nanoporous compound with tunable electronic properties. The charge transport mechanisms and their variation with the degree of reduction x in the [Ca24Al28O64](4+)(2O(2-))((1-x))(4e(-))(x) system are still not fully understood. In this study, Hall-measurements and electron paramagnetic resonance (EPR) spectroscopy were used to characterize a series of polycrystalline [Ca24Al28O64](4+)(2O(2-))((1-x))(4e(-))(x) samples with different x, providing detailed insight into the electronic properties of the material.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Spectroscopy
Hannes Hergert, Matthias T. Elm, Peter J. Klar
Summary: We evaluate Raman spectroscopy as a fast and non-invasive method for mapping charge carrier density and carrier mobility in inhomogeneously doped 4H-SiC. A comparison between magneto-transport and Raman measurements of N-doped 4H-SiC reveals deviations in the extracted transport parameters, suggesting the need for an improved analysis model. By employing a three-band transport model, it is confirmed that only the free charge carriers in the conduction band contribute to the observed Raman signal.
JOURNAL OF RAMAN SPECTROSCOPY
(2023)
Article
Chemistry, Multidisciplinary
Hendrik Hemmelmann, Raffael Ruess, Philip Klement, Joerg Schoermann, Sangam Chatterjee, Joachim Sann, Matthias T. Elm
Summary: Depositing ultrathin oxide coatings has been proven an effective method to stabilize the surface of LiNixCoyMnzO2 active cathode material in lithium-ion batteries. While an aluminum oxide coating improves long-term cycling stability, a cerium oxide coating performs even worse than uncoated counterparts. X-ray photoelectron spectroscopy analysis reveals that both coatings are fluorinated upon contact with liquid electrolyte. The fluorinated aluminum oxide coating remains stable during cycling, leading to improved cell performance, while the fluorinated cerium oxide coating undergoes chemical composition changes and facilitates corrosion of the cathode material.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Hendrik Hoffmann, Melanie Cornelia Paulisch-Rinke, Marius Gernhard, Yannick Jaennsch, Jana Timm, Carola Brandmeir, Steffen Lechner, Roland Marschall, Ralf Moos, Ingo Manke, Christina Roth
Summary: In this paper, the authors characterize the structure and performance of silver foam electrodes in CO2 reduction by combining physicochemical and microscopic techniques with electrochemical analysis. They reveal that electrochemical deposition at higher current densities leads to a more uniform and dense structure, resulting in improved CO2 conversion efficiency.
COMMUNICATIONS CHEMISTRY
(2023)
Article
Nanoscience & Nanotechnology
Janis K. Eckhardt, Sascha Kremer, Till Fuchs, Philip Minnmann, Johannes Schubert, Simon Burkhardt, Matthias T. Elm, Peter J. Klar, Christian Heiliger, Ju''rgen Janek
Summary: This study investigates the effects of microstructure on the material-specific properties of garnet-type Li7La3Zr2O12 ceramics. By employing a combinatorial approach of structural analysis and three-dimensional transport modeling, the researchers found that variations in grain size and porosity can lead to uncertainties of up to 150% in the derived transport parameters. Understanding the influence of microstructure on experimental results is crucial for improving the reproducibility and comparability of research findings.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Janis K. Eckhardt, Christian Heiliger, Matthias T. Elm
Summary: Ordered mesoporous oxides with their unique architecture have shown potential in various electrochemical applications such as gas sensing and energy storage. The high accessibility of the internal surface allows for tailoring of their electrochemical properties, resulting in superior performance compared to other materials. However, reliable electrochemical characterization is hindered by the complex interplay between nanocrystalline grains, grain boundaries, and the pore framework. A 3D electric network model was used to investigate the impact of the pore structure on the electrical transport properties of mesoporous thin films. An empirical expression was derived that allows for the determination of the material-specific conductivity with less than 8% error.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Janik Luechtefeld, Hendrik Hemmelmann, Susanne Wachs, Christopher Behling, Karl J. J. Mayrhofer, Matthias T. Elm, Balazs Berkes
Summary: The dissolution of cathode active material is a major issue in battery aging. In this study, the potential-dependent transition metal dissolution from lithium-ion battery cathodes was investigated using an electrochemical flow cell and inductively coupled plasma mass spectrometry. The results showed that thin-film LiCoO2 cathodes exhibited uniform dissolution, while commercial composite cathode tapes had lower relative dissolution. Furthermore, the second cycle was found to have the highest dissolution.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Nils Neugebauer, Yi Wang, Matthias T. Elm, Detlev M. Hofmann, Christian Heiliger, Xingchen Ye, Peter J. Klar
Summary: This paper investigates the two-dimensional monolayer structures of magnetic nanoparticles on silicon substrates and finds that there is a distance-dependent dipolar interaction between the nanoparticles, which affects the collective response of the corresponding mesocrystals. Experimental and theoretical analysis reveals that the magnetization and magnetocrystalline anisotropy of the nanoparticles are reduced compared to their bulk values.
Article
Green & Sustainable Science & Technology
Judith Zander, Morten Weiss, Roland Marschall
Summary: Nanoparticles of cubic CuFe2O4 were synthesized quickly through microwave-assisted hydrothermal method and achieved high phase purity and crystallinity at short reaction times or low temperatures. The effects of synthesis time and temperature on material properties and electrochemical CO2 reduction performance were investigated. The best performance was obtained for CuFe2O4 with intermediate degree of inversion, which showed high CO evolution rate and promising potential for sustainable production of syngas.
ADVANCED ENERGY AND SUSTAINABILITY RESEARCH
(2023)
