Article
Engineering, Electrical & Electronic
Apu Mondal, S. Pal, Suvadip Masanta, Sourabh Pal, Rajib Saha, Pravin Kumar, A. Singha, S. Chattopadhyay, D. Jana, A. Sarkar
Summary: The study found that rapid thermal annealing helps to maintain nitrogen at lattice positions, while conventional furnace annealing promotes nitrogen outdiffusion, also explaining the mechanism of nitrogen enrichment in ZnO.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Chemistry, Physical
Amaresh Das, Durga Basak
Summary: This study presents a comprehensive investigation on the interplay between nitrogen and various defects in ZnO nanorods, revealing that nitrogen implantation induces structural damages and forms nitrogen-related defect complexes. Post-implantation annealing in O2 and Ar environments plays a key role in stabilizing nitrogen dopants in ZnO nanorods.
APPLIED SURFACE SCIENCE
(2021)
Article
Physics, Multidisciplinary
Qing-Fen Jiang, Jie Lian, Min-Ju Ying, Ming-Yang Wei, Chen-Lin Wang, Yu Zhang
Summary: The structures, morphologies, and optical properties of Zn-polar ZnO films modified by ion implantation with different concentrations of krypton ions were investigated. The absorption spectrum, photoluminescence, and spectroscopic ellipsometry results showed that krypton ion implantation led to increased absorption, reduced bandgap, and decreased refractive index in the films. This study contributes to the design and optimization of krypton ion-implanted polar ZnO films for optoelectronic applications.
Article
Materials Science, Composites
Ali F. Al-Shawabkeh, Ziad M. Elimat, Khaleel N. Abushgair
Summary: The study investigates the optical properties of PVC/ZnO nanocomposite films. The results show that the optical properties of the films are dependent on the concentration of ZnO and the wavelength of light, and the optical parameters can be influenced by altering the concentration of non-annealed and annealed ZnO nanoparticles in the PVC matrix.
JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
W. Chrominski, L. Ciupinski, P. Bazarnik, S. Markelj, T. Schwarz-Selinger
Summary: Tungsten targets undergo self-damage and defect decoration with ions, followed by high-temperature annealing to study defect evolution. Helium implantation increases dislocation density, and the implanted zone serves as the source of internal stress fields, which are released through thermal treatment.
MATERIALS CHARACTERIZATION
(2021)
Article
Environmental Sciences
Kirill Azarin, Alexander Usatov, Tatiana Minkina, Nadezhda Duplii, Alexandra Kasyanova, Aleksei Fedorenko, Vladimir Khachumov, Saglara Mandzhieva, Vishnu D. Rajput
Summary: The functioning of photosynthesis in barley was studied after exposure to different concentrations of bulk and nanosized ZnO. The results showed that chlorophyll content, photosynthetic efficiency, and zinc accumulation in chloroplasts were affected, with more pronounced changes observed with nanosized ZnO exposure. Gene expression analysis revealed different sensitivities to the two types of ZnO exposure. The study highlights the importance of understanding the impact of nanoparticles on crop photosynthesis for food security.
ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Electrical & Electronic
Toshiaki Kunikata, Takumi Kato, Daiki Shiratori, Daisuke Nakauchi, Noriaki Kawaguchi, Takayuki Yanagida
Summary: ZnO translucent ceramics were synthesized by spark plasma sintering, and annealed at temperatures ranging from 600 to 800 degrees C to improve photoluminescence and scintillation properties. The annealing process decreased absorption due to oxygen vacancies, leading to improved PL quantum yields and scintillation light yields. The ZnO translucent ceramic annealed at 750 degrees C exhibited the highest PL quantum yield (25.1%) and light yields (44,200 ph/5.5 MeV-alpha and 30,500 ph/MeV).
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Chemistry, Physical
Norhilmi Zahir, Noor Azrina Talik, Hazmi Naim Harun, Anas Kamarundzaman, Sarayut Tunmee, Hideki Nakajima, Narong Chanlek, Ahmad Shuhaimi, Wan Haliza Abd Majid
Summary: The properties of ITO films were found to be directly correlated with the substrate temperature during deposition. A substrate temperature of 450 degrees C was determined to produce the best ITO/p-GaN properties, exhibiting high power efficiency and the highest conduction band offset.
APPLIED SURFACE SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Qian Li, Mengdi Zhang, Miaomiao Yuan, Wei Cheng, Bin Liao, Minju Ying
Summary: This study presents a comprehensive experimental and theoretical investigation on the effects of surface polarity on the structure and ferromagnetic properties of Co and Co-Sm co-implanted polar ZnO films. The results show that O-polar ZnO exhibits stronger ferromagnetism, possibly due to the combination of more oxygen vacancies and larger local moments related to Co and Sm doping.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Ceramics
Ashis K. Manna, P. Dash, Dip Das, S. K. Srivastava, P. K. Sahoo, A. Kanjilal, D. Kanjilal, Shikha Varma
Summary: We present the photoabsorption response and resistive switching behavior of ion-implanted ZnO thin films. The role of oxygen vacancies in the evolution of these properties is studied using various techniques. The results suggest an improvement in the crystallinity of the films with ion fluence, and an enhancement in oxygen vacancy is responsible for higher photo response in the UV-Vis range. Engineering of bandgap also introduces enhanced absorption in visible regime. An asymmetric resistive switching behavior is observed in films implanted at the highest fluence, with a switching behavior from a high resistance state to a low resistance state under positive bias conditions and a rectifying nature under negative bias conditions. Oxygen vacancies play a crucial role in the modulation of photoabsorption response and resistive switching mechanism.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Physical
Huining Jin, Andrew A. Bettiol
Summary: The guiding performance of 2-MeV proton implanted diamond waveguides was studied and it was found that the normalized intensity of the 1332 cm(-1) Raman line can be used as a generic parameter to quantify structural damage caused by implantation, serving as an indicator of guiding performance. Experimental observations were supported by finite element simulation, and a single linear relationship was employed to simulate all experimental mode profiles. The use of proton beam writing and measured I-Raman shows potential for designing and manufacturing light-guiding structures directly in bulk single crystal diamond.
Article
Materials Science, Multidisciplinary
Tuo Sheng, Xing-Zhao Liu, Ling-Xuan Qian, Bo Xu, Yi-Yu Zhang
Summary: Metal-semiconductor-metal solar-blind ultraviolet photoconductors based on beta-Ga2O3 thin films were fabricated and the effects of annealing on their characteristics and photoconductivity were studied. Higher annealing temperature resulted in lower crystalline quality and device photoresponsivity. The vacuum-annealed sample showed the highest photoresponsivity and the oxygen-annealed sample effectively suppressed persistent photoconductivity.
Article
Physics, Applied
M. A. Makhavikou, O. Milchanin, I. N. Parkhomenko, L. A. Vlasukova, F. F. Komarov, V. N. Yuvchenko, E. Wendler, D. S. Korolev, A. Mudryi, V. D. Zhivulko, A. Janse van Vuuren
Summary: The phase-structural composition of silica films grown on Si substrates implanted with different fluences of Zn ions has been studied using TEM and electron diffraction. Small and larger clusters were formed in the as-implanted silica films with Zn concentration of 6-8 at% and 16-18%, respectively. Furnace annealing at 750°C resulted in the formation of orthorhombic Zn2SiO4 phase for low fluence and the formation of zinc blended ZnO phase for high fluence.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
Chenlin Wang, MinJu Ying, Jie Lian, MingYang Wei, Qingfen Jiang, Zhen Xu, Yu Zhang, Yueming Wang
Summary: In this work, ion implantation of Mn and As ions into ZnO films significantly altered their optical properties, leading to changes in refractive index and extinction coefficient. The presence of Mn ions also introduced a halfmetallic property to the ZnO films, resulting in gentler variations in optical characteristics. These findings suggest new possibilities for the design and optimization of optoelectronic devices utilizing ZnO thin films with semi-metallic properties.
APPLIED SURFACE SCIENCE
(2022)
Article
Nanoscience & Nanotechnology
Sergey Astafurov, Elena Astafurova, Kseniya Reunova, Evgenii Melnikov, Marina Panchenko, Valentina Moskvina, Galina Maier, Valery Rubtsov, Evgenii Kolubaev
Summary: High nitrogen steel billets were produced using electron-beam additive manufacturing with significant changes in microstructure and composition during solidification. The dual-phase structure and morphology play crucial roles in the performance of high-nitrogen steel.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Physics, Applied
Z. Dela Cruz, C. Hou, R. F. Martinez-Gazoni, R. J. Reeves, M. W. Allen
Summary: The performance of beta-Ga2O3 Schottky contacts (SCs) fabricated using amorphous, intentionally oxidized platinum-iridium alloys was investigated. The study found that Pt0.5Ir0.5Ox SCs had the highest Schottky barriers on all beta-Ga2O3 crystal faces, providing better contacts and lower reverse leakage currents. All PtyIr(1-y)Ox SCs on ( 2 over bar 01) beta-Ga2O3 showed excellent high-temperature performance.
APPLIED PHYSICS LETTERS
(2022)
Article
Environmental Sciences
S. Panimalar, M. Subash, M. Chandrasekar, R. Uthrakumar, C. Inmozhi, Wedad A. Al-Onazi, Amal M. Al-Mohaimeed, Tse-Wei Chen, J. Kennedy, M. Maaza, K. Kaviyarasu
Summary: In this study, Sn-doped MnO2 nanostructures were successfully synthesized via a basic sol-gel reaction. The results showed that Sn-doped MnO2 exhibited higher catalytic performance in the visible spectrum. By adjusting the doping ratio of Sn, the degradation efficiency and stability of the catalyst can be further optimized.
Article
Chemistry, Physical
S. Ahmed, X. Y. Cui, Peter P. Murmu, X. Ding, X. Z. Chu, C. I. Sathish, N. N. Bao, R. Liu, W. Y. Zhao, J. Kennedy, T. Tan, M. Peng, L. Wang, J. Ding, Tom Wu, X. L. Wang, S. Li, A. Vinu, S. R. Ringer, J. B. Yi
Summary: This work investigates the magnetism in layered two-dimensional materials by doping cobalt into MoTe2 single crystal. The results show that even small amounts of cobalt doping can induce high saturation magnetization, and 4% cobalt doping exhibits a higher saturation magnetization than pure metallic iron. Additionally, the 2% cobalt-doped MoTe2 sample shows an oversized coercivity, which may be attributed to doping-induced structural defects, stress, anisotropic geometry of cobalt-tellurium ions, and pinning effects by defects.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Electrochemistry
Jingjing Liu, John Kennedy, Aaron Marshall, James Metson, Mark P. Taylor
Summary: This paper examines the research gaps related to electrochemical dynamics in the water electrolysis industry, specifically the detrimental effects of electrode effects on electrolyzers. By comparing the current research on industrial electrode effects and the existing thermal thresholds observed in water electrolysis, the importance of detecting electrode effects in water electrolyzers is explored.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Review
Chemistry, Multidisciplinary
Jinlong Liu, Ziyu Luo, Xichen Mao, Yusong Dong, Lishan Peng, Dongxiao Sun-Waterhouse, John Kennedy, Geoffrey I. N. Waterhouse
Summary: This article reviews the recent progress in developing self-supported heterostructured semiconductor nanoarrays as efficient photoanode catalysts for water oxidation in photoelectrochemical (PEC) water splitting. By controlling the growth conditions, heterojunction nanoarrays with different morphologies and semiconductor components can be fabricated, leading to improved light-absorption properties, stabilities, and PEC activities. The article discusses various synthetic methods and summarizes the reported heterojunction nanoarrays based on specific core semiconductor scaffolds, highlighting the synergies generated at the interface between the semiconductor components that enhance PEC water oxidation.
Article
Materials Science, Multidisciplinary
R. A. Sharath, F. Fang, J. Futter, W. J. Trompetter, G. Singh, A. Vinu, J. Kennedy
Summary: This study reports a controlled one-step thermal approach for creating nitrogen defects and modifying the overall structure of g-C3N4 without adding any external reducing/oxidizing agent. The defect-modified g-C3N4 showed increased surface area and bandgap compared to raw g-C3N4.
EMERGENT MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Sohail Ahmed, Peter P. P. Murmu, Clastinrusselraj Indirathankam Sathish, Xinwei Guan, Rex Geng, Nina Bao, Rong Liu, John Kennedy, Jun Ding, Mingli Peng, Ajayan Vinu, Jiabao Yi
Summary: Magnetic 2D-layered materials have great potential for spintronic devices and compact magnetic devices. Introducing a magnetic element into 2D-layered materials is an effective strategy to synthesize magnetic materials. By ion implantation, Co and Nd were codoped into MoS2 crystals, achieving extremely high magnetization at both low and room temperatures. This study opens up a useful strategy to develop high-performance magnetic materials based on 2D-layered materials.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Holger Fiedler, Prasanth Gupta, Jerome Leveneur, David R. G. Mitchell, Mitchell Nancarrow, John Kennedy
Summary: We report the ion beam synthesis of buried two-dimensional AlGaN structures with enhanced piezoelectric modulus. The presence of the 2D layers was confirmed by scanning transmission electron microscopy. Alternating planar and buckled 2D III-Nitride layers with a rapid change of polarity of the buckled layer suggest weak interaction between the layers. Our results suggest the potential applications of this material in efficient energy harvesters, communication devices, power devices, and photocatalytic water splitting technologies.
APPLIED MATERIALS TODAY
(2023)
Review
Materials Science, Multidisciplinary
Michael Ng, Vedran Jovic, Geoffrey I. N. Waterhouse, John Kennedy
Summary: Methanol production from CO2 and H-2 has gained attention as a sustainable alternative to current production methods. Researchers are seeking photothermal catalysts to achieve optimal reaction temperatures for CO2 hydrogenation to CH3OH. Although promising catalysts have been discovered, the production rates of methanol using photothermal catalysis are still modest compared to thermochemical catalysis routes. This review summarizes recent progress in the field and explores strategies for higher CO2 conversion rates and higher CH3OH yields in the future.
EMERGENT MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Bill Trompetter, Jerome Leveneut, Max Goddard-Winchester, Ben Rumsey, James Turner, Graham Weir, John Kennedy, Shen Chong, Nick Long
Summary: The magnetic performance of ferrite based soft magnetic composite materials (SMCs) for inductive power transfer (IPT) applications in roads was investigated. The magnetic permeabilities and losses of SMCs were characterized for different ferrite particle size fractions and loadings. The study showed that the crushed ferrite powders had higher magnetic performance than expected based on magnetic particle theory for spherical magnetic particles. The findings were confirmed by comparing the magnetic performance of SMCs made from spherically ground ferrite powders.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Chemistry, Analytical
Anmol Mahendra, Peter P. Murmu, Susant Kumar Acharya, Atif Islam, Holger Fiedler, Prasanth Gupta, Simon Granville, John Kennedy
Summary: In this study, the perpendicular magnetic anisotropy (PMA) of Co2MnGa Heusler alloy film was tuned by argon ion irradiation. The results showed that ion irradiation reduced the effective anisotropy energy and PMA of the film, which is beneficial for magnetic sensor applications.
Article
Materials Science, Multidisciplinary
P. Gupta, V. Jovic, R. Huebner, E. Anquillare, K. Suschke, K. E. Smith, A. Markwitz, G. I. N. Waterhouse, J. Kennedy
Summary: A one-step approach to synthesize ultrafine metallic cobalt nanoparticles at room temperature by cobalt ion implantation into amorphous carbon films and hydrogenated amorphous carbon films was explored. It was found that hydrogenated carbon films suppressed the aggregation of metallic cobalt nanoparticles, leading to the formation of ultrafine cobalt nanoparticles with a size smaller than 5 nm.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Holger Fiedler, Niall Malone, David R. G. Mitchell, Mitchell Nancarrow, Vedran Jovic, Geoffrey I. N. Waterhouse, John Kennedy, Prasanth Gupta
Summary: Molybdenum carbides are potential low-cost electrocatalysts for electrolyzers, fuel cells, and batteries. This study presents a scalable, physical approach to synthesize molybdenum carbide nanoparticles at room temperature by ion implantation, with the ability to control the phase, stoichiometry, and size of the nanoparticles. The results are explained using the Mo-C phase diagram and Monte-Carlo simulations, and the approach can be applied to synthesize other transition metal carbide nanoparticles.
Article
Materials Science, Multidisciplinary
Graham Weir, William Trompetter, Jerome Leveneur, Nick Long, James Turner, John Kennedy
Summary: This paper develops a theory of low loss, unbiased minor loops in an isothermal macroscopic composite of soft magnetic particles. The theory predicts an effective macroscopic shape factor for the composite based on the average of the inverse shape factors of the particles. The low loss and composite nature of the material imply self-similarity and conjugacy of the hysteresis loops. The resulting theory depends on two non-dimensional numbers, with being a small number determining magnetic energy loss for a minor loop, while is approximately unity and determines the skewness of the minor loops. The theory is tested against different volume fractions of magnetic ferrite powder composite, supporting the concept of self-similarity in the low loss regime.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Chemistry, Physical
Peter P. Murmu, John Kennedy, Zihang Liu, Takao Mori
Summary: This study found that sulfur doping by ion implantation can improve the electrical conductivity and power factor of copper iodide films. At low fluences, sulfur doping increases both the electrical conductivity and the Seebeck coefficient significantly. The nature of sulfur ions changes at high fluences, and the solubility of sulfur affects the defect chemistry and thermoelectric properties of sulfur-implanted copper iodide films.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
