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
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
Materials Science, Multidisciplinary
Zijun Ma, Yanping Wei, Jijun Ding, Peirong Chang, Jinxiu Guo, Zhen Peng
Summary: Either metal/metal or metal/non-metal co-doping is an effective method to modulate the visible emission of ZnO. In this study, ZnO films doped with aluminum, silver, and nitrogen were deposited, and their photoluminescence characteristics were investigated. The enhancement mechanism of visible light emission was discussed based on experimental and theoretical results.
Article
Materials Science, Multidisciplinary
R. Siddheswaran, C. Esther Jeyanthi, K. Thangaraju, R. Mangalaraja
Summary: The present investigation explores the columnar structured growth of Mn doped ZnO (MZO) thin films using the radio frequency sputtering technique. Various characterization techniques, such as X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, were employed to confirm the structure, composition, and growth direction of the MZO films.
MATERIALS TECHNOLOGY
(2022)
Article
Chemistry, Physical
Qian Li, Weiqing Yan, Heng Yuan, Shunian Chen, Bin Liao, Minju Ying
Summary: The present study reports room temperature ferromagnetism observed in Co implanted, Er implanted and (Co, Er) co-implanted ZnO films deposited by filtered cathode vacuum arc (FCVA) on sapphire substrates. The electrical properties and magnetic properties of the doped ZnO films were improved, and significant intrinsic ferromagnetism was observed. The results can provide a reference for preparing high-quality diluted magnetic semiconductors (DMSs) by co-doping RE elements and TM elements in ZnO films.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
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
Nanoscience & Nanotechnology
Qian Li, Yifan Zhang, Weiqing Yan, Mengdi Zhang, Wei Cheng, Bin Liao, Minju Ying
Summary: In this study, the microstructural and magnetic properties of Co-doped Zn polar and O polar ZnO wafers prepared by ion implantation method were investigated. It was found that all the doped ZnO wafers exhibited substantial intrinsic ferromagnetism, with higher ferromagnetism observed in Co-implanted oxygen polar ZnO compared to zinc polar ZnO. First principle calculations revealed that the magnetic moments mainly originated from the Co-3d and O-2p states, with stronger hybridization between the O-2p state and the Co-3d state in oxygen polar ZnO, resulting in higher magnetic moments in Co-implanted oxygen polar ZnO. These findings not only provide a better understanding of the origin of surface-polarity dependent ferromagnetism in ZnO diluted magnetic semiconductors, but also have the potential to enable the use of these polar ZnO materials in spintronic devices.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Physical
Nur Amaliyana Raship, Siti Nooraya Mohd Tawil, Nafarizal Nayan, Khadijah Ismail, Anis Suhaili Bakri, Zulkifli Azman, Faezahana Mohkhter
Summary: The influence of doping and co-doping process on ZnO films was characterized, showing successful incorporation of Gd and Al ions into ZnO lattice. The films exhibited high transparency and red-shifted optical band gap with increasing Gd doping concentration. Co-doping with Al resulted in the presence of ferromagnetism and spin polarization. The electrical properties were improved by the incorporation of Al into Gd-doped ZnO thin films.
Article
Materials Science, Multidisciplinary
Richa Bhardwaj, Amardeep Bharti, Baljeet Kaur, Manish Kumar, Asokan Kandasami, Keun Hwa Chae, Navdeep Goyal
Summary: The impact of different nickel ion fluence on ZnO films grown on Si(100) substrates via radio frequency sputtering was studied. It was found that with increasing nickel ion fluence, the crystallite size of ZnO films increased, and stress gradients appeared. Additionally, nickel-implanted ZnO/Si(100) films exhibited room temperature ferromagnetism.
Article
Materials Science, Multidisciplinary
Abeer Salah, Ahmed M. Saad, Ahmed A. Aboud
Summary: The pure and Co-doped ZnO thin films were studied with different levels of Co doping. The grain size increased with Co doping, optical band gap showed changes, and the dispersion transitioned from anomalous to normal upon Co doping. The doped materials exhibited reverse saturable absorption and negative nonlinear refraction.
Article
Materials Science, Coatings & Films
Tomas Fiantok, Viktor Sroba, Nikola Koutna, Vitalii Izai, Tomas Roch, Martin Truchly, Marek Vidis, Leonid Satrapinskyy, Stefan Nagy, Branislav Grancic, Peter Kus, Marian Mikula
Summary: Alloying with aluminum significantly affects the thermally induced structure evolution and mechanical properties of alpha-structured zirconium diboride films. Aluminum forms a nanocomposite structure with zirconium diboride, but is insoluble in the zirconium diboride phase. Alloying with aluminum decreases the hardness, but after annealing, the hardness slightly increases due to increased point defects at the boundaries. The Young's modulus decreases with aluminum alloying.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Nanoscience & Nanotechnology
Kota Udagawa, Mariko Murayama, Xinwei Zhao
Summary: In this study, Co-doped ZnO thin films were fabricated using pulsed laser deposition under different oxygen partial pressures. The research found that the valence state of Co ions was 2+ and the number of oxygen vacancies increased with lowering oxygen partial pressure. The substitution of Co2+ ions for Zn sites in the ZnO lattice was confirmed by UV-visible absorption spectroscopy. The Co-doped ZnO thin films exhibited ferromagnetism at room temperature, and the saturation magnetization showed a strong correlation with the number of oxygen vacancies.
Article
Materials Science, Multidisciplinary
Weon Cheol Lim, Jitendra Pal Singh, Younghak Kim, Jonghan Song, Keun Hwa Chae, Tae-Yeon Seong
Summary: The study shows that thermal annealing significantly affects the properties of zinc oxide thin films, including relaxation of stress, variation in optical band-gap, and occurrence of vacancies and defects. These changes are revealed through X-ray techniques, providing a better understanding of the performance changes in zinc oxide films.
Article
Optics
Akshai Shyam, Durga S. Nair, T. K. Drishya, Ramasubramanian Swaminathan, Thangavel Rajalingam
Summary: Investigations were conducted to study the effects of co-doping with alkali elements (Li, Na, and K) on the structural, optical, and morphological characteristics of thin Co-ZnO films deposited using the sol-gel spin coating technique. Structural investigations revealed a wurtzite structure with [002] fiber texture in the coated films. Optical studies inferred the substitution of Co2+ in the ZnO lattice. The nature of defect emissions in the photoluminescence spectra varied with the incorporation of different alkali elements. Resonance Raman measurements observed multiple LO phonons up to the tenth order in the coated thin films. Magnetic force microscopy was utilized to understand the distribution of magnetism and the existence of Co metallic clusters in the grown thin films.
Article
Chemistry, Physical
Izabell Craciunescu, Elena Chitanu, Mirela M. Codescu, N. Iacob, A. Kuncser, V. Kuncser, V. Socoliuc, Daniela Susan-Resiga, Florica Balanean, G. Ispas, Tunde Borbath, I. Borbath, Rodica Turcu, L. Vekas
Summary: High magnetization Fe3O4/OA-FeCo/Al2O3 nanocomposite magnetic clusters were successfully synthesized via a modified oil-in-water miniemulsion method. These clusters, with a combination of magnetite nanoparticles and FeCo/Al2O3 particles, exhibited enhanced magnetic and flow properties in ferrofluid carrier. The unique structure and composition of the Fe3O4/OA-FeCo/Al2O3 clusters contribute to their promising performance as a new type of nanocomposite magnetorheological fluid, as demonstrated by advanced characterization techniques.
Article
Materials Science, Ceramics
Sara Ait Bouzid, Abdellatif Essoumhi, Arpad Mihai Rostas, Andrei Cristian Kuncser, Constantin Catalin Negrila, Nicusor Iacob, Andrei Galatanu, Bogdan Popescu, Mohammed Sajieddine, Aurelian Catalin Galca, Victor Kuncser
Summary: Poly-crystalline La(0.8)K(0.2-x)Pb(x)MnO3 (x = 0.05, 0.10, 0.15, 0.20) ceramics were successfully prepared by flash combustion route and their structural, morphological, magnetic and magnetocaloric properties were investigated. Results showed that Pb doping changes the grain size and lattice parameters without modifying the crystal structure. La0.8K0.1Pb0.1MnO3 exhibited significant magnetocaloric properties near room temperature.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Physical
A. Birsan, V Kuncser
Summary: The research efforts in this study focused on implementing Heusler materials into spintronic heterostructures, specifically investigating the half-metallic and magnetic properties of Zr2CrAl ferrimagnetic compound. Theoretical investigations using Density Functional Theory were conducted on different distortions of the inverse-Heusler cubic crystalline structure. The results showed that the compound exhibited half-metallic characteristics for all considered distortions, and the slight variations in unit cell volume did not affect its high spin polarization state. The calculated magnetic moment per formula unit followed the Slater-Pauling rule, and the antiferromagnetic coupling between Zr and Cr atoms was preserved.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Outman El Khouja, Constantin Catalin Negrila, Khalid Nouneh, Mihail Secu, Mohamed Ebn Touhami, Elena Matei, Viorica Stancu, Monica Enculescu, Victor Kuncser, Aurelian Catalin Galca
Summary: In this study, stannite Cu2FeSnS4 absorber films with good stoichiometry and high crystallinity were successfully obtained through sulfurization treatment at certain temperatures. The impact of annealing temperature on the properties of CFTS films was investigated, revealing significant effects on the optical and chemical characteristics.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Anda Elena Stanciu, Gabriel Schinteie, Andrei Cristian Kuncser, Claudiu Locovei, Lucian Trupina, Nicusor Iacob, Aurel Leca, Bogdana Borca, Victor Kuncser
Summary: This study investigates the vectorial magnetic properties of nanostructured systems and thin films of Fe and FeCo. The magnetic properties are engineered by controlling the parameters of the thin films. Magnetic nanowires and magnetic islands/clusters are distinguished on undulating thin films.
Article
Chemistry, Physical
Silvia Mauri, Gianluca D'Olimpio, Corneliu Ghica, Luca Braglia, Chia-Nung Kuo, Marian Cosmin Istrate, Chin Shan Lue, Luca Ottaviano, Tomasz Klimczuk, Danil W. Boukhvalov, Antonio Politano, Piero Torelli
Summary: This study investigates the surface reactivity of a Ni3Sn4 catalyst operating at 250 degrees C for hydrogen production from methanol decomposition. It is found that the catalytic reaction is driven by surface tin-oxide phases, which enhance catalyst durability and H2 selectivity. These findings provide new perspectives for the development of scalable and low-cost catalysts.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Marwene Oumezzine, Cristina Florentina Chirila, Iuliana Pasuk, Aurelian Catalin Galca, Aurel Leca, Bogdana Borca, Victor Kuncser
Summary: In this study, a ferromagnetic perovskite thin film was successfully grown on a single crystal substrate, and its magnetic, magnetocaloric, and magnetoresistance properties were investigated. The film exhibited high crystallinity and in-plane uni-axial magnetic anisotropy, showing a ferromagnetic-paramagnetic phase transition and a metal-semiconductor transition near room temperature.
Editorial Material
Chemistry, Multidisciplinary
Victor Kuncser
Summary: Multifunctional magnetic nanocomposites are heterogeneous nanosized systems with at least one magnetic phase component, which can act as an intermediate for the actuation or response of the overall system. The electronic properties of the constituent interfaced nanophases can be combined and influenced in these systems, resulting in unique physico-chemical properties for various applications.
Article
Chemistry, Multidisciplinary
Luiza Izabela Toderascu, Livia Elena Sima, Stefana Orobeti, Paula Ecaterina Florian, Madalina Icriverzi, Valentin-Adrian Maraloiu, Cezar Comanescu, Nicusor Iacob, Victor Kuncser, Iulia Antohe, Gianina Popescu-Pelin, George Stanciu, Petre Ionita, Cristian N. N. Mihailescu, Gabriel Socol
Summary: In this study, L-Cysteine-coated magnetic iron oxide nanoparticles loaded with doxorubicin were synthesized and extensively characterized. The binding of doxorubicin to L-Cysteine was confirmed, and the internalization of the nanoparticles delivering doxorubicin was observed in melanoma cells. The nanoparticles also modulated cell signaling pathway activity, induced cell cycle arrest and apoptosis, and exhibited pH-dependent drug release. These results demonstrate the potential of the nanoparticles as efficient drug delivery vehicles in melanoma therapy.
Article
Pharmacology & Pharmacy
Lavinia Brazdaru, Teodora Staicu, Madalina Georgiana Albu Kaya, Ciprian Chelaru, Corneliu Ghica, Viorel Circu, Minodora Leca, Mihaela Violeta Ghica, Marin Micutz
Summary: The treatment of wounds requires appropriate dressings to ensure tissue regeneration and prevent bacterial infections. In this study, we designed an algorithm to monitor and analyze the release of antimicrobial agents from collagen-based matrices. By controlling the crosslinking degree and loading content, a tunable and sustainable release profile can be achieved.
Article
Chemistry, Analytical
Adelina Stanoiu, Corneliu Ghica, Catalina Gabriela Mihalcea, Daniela Ghica, Cristian Eugen Simion
Summary: In this study, two alternative synthesis routes were used to obtain gas-sensitive NiO materials. The structural and morphological aspects were systematically investigated, revealing significant differences in their sensing performances. The study considered multiple energy contributions and proposed two sensing mechanisms to explain the variation in CO sensor response, with the influence of relative humidity also taken into account.
Article
Chemistry, Physical
Federico Mazzola, Yanxue Zhang, Natalia Olszowska, Marcin Rosmus, Gianluca D'Olimpio, Marian Cosmin Istrate, Grazia Giuseppina Politano, Ivana Vobornik, Raman Sankar, Corneliu Ghica, Junfeng Gao, Antonio Politano
Summary: Nonmagnetic chiral crystals are a new type of materials that possess Kramers-Weyl Fermions due to the combination of structural chirality, spin-orbit coupling, and time-reversal symmetry. These materials exhibit unique Fermi surfaces with spin-orbit coupling-induced Chern gaps, leading to exotic transport and optical properties. This study investigates the electronic structure and transport properties of CdAs2, a recently discovered chiral material, using angle-resolved photoelectron spectroscopy and density functional theory. The results suggest that CdAs2 is a promising candidate for novel topological properties and provide valuable insights for the development of spintronic and optical devices based on chiral charges and nontrivial Chern numbers.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Ileana Cristina Vasiliu, Ana Violeta Filip, Irinela Chilibon, Mihail Elisa, Cristina Bartha, Victor Kuncser, Aurel Leca, Lucica Boroica, Bogdan Alexandru Sava, Roxana Trusca, Mihai Eftimie, Adrian Nicoara
Summary: This study investigates a convenient and low-cost sol-gel approach for synthesizing ZnO-P2O5-rGO nanostructures with tuned bandgap and fluorescence. The obtained hybrid nanostructures combine the properties of zinc oxide, graphene oxide, and phosphorous oxide, making them promising candidates for a wide range of optoelectronic applications.
Article
Chemistry, Physical
Francesco Cordero, Floriana Craciun, Patrizia Imperatori, Venanzio Raglione, Gloria Zanotti, Antoniu Moldovan, Maria Dinescu
Summary: In this study, we measured the properties of a metal-free molecular perovskite material and found that it exhibits ferroelectricity below a certain temperature. We also observed that the material deteriorates and loses mass at high temperatures, leading to a decrease in performance. Unlike traditional ferroelectric materials, the elastic modulus of this material weakens before the ferroelectric phase. The degradation of the material is attributed to point defects, and a method for calculating the defect concentration is proposed.
Review
Chemistry, Multidisciplinary
V Socoliuc, M. Avdeev, V Kuncser, Rodica Turcu, Etelka Tombacz, L. Vekas
Summary: Ferrofluids are colloidal suspensions of magnetic nanoparticles with fluid and magnetic properties, which have been investigated for over five decades. They have proven to be highly controllable and tunable, making them suitable for a wide range of engineering applications. Recently, biocompatible ferrofluids have attracted significant interest for their potential applications in nanomedicine, biotechnology, and environmental protection. This paper provides an overview of early results, as well as recent advancements in ferrofluid synthesis, characterization, ferrohydrodynamics, and applications in sensors, actuators, and droplet technology.