Article
Chemistry, Physical
M. P. F. de Godoy, X. Gratens, V. A. Chitta, A. Mesquita, M. M. de Lima Jr, A. Cantarero, G. Rahman, J. M. Morbec, H. B. de Carvalho
Summary: This study reports on achieving room temperature ferromagnetism in ZnO samples through Co-doping. By introducing controlled defects via heat treatments in a reductive atmosphere and conducting structural analysis and magnetometry, the magnetic behavior is fully explained in terms of the bound magnetic polaron model. The origin of the observed defect-induced ferromagnetism is attributed to the ferromagnetic coupling between Co ions mediated by magnetic polarons due to zinc interstitial defects.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Review
Biochemistry & Molecular Biology
Sebastian Salazar Sandoval, Nataly Silva
Summary: This review uncovers mechanical milling as an alternative method for producing copper-based particles (CuP) and copper composites (CuC) on a lab-scale via a top-down or bottom-up approach. The review highlights the various parameters that influence the size distribution, type, and morphology of the resulting CuP or CuC, such as the mechanical mill type, ball-to-powder ratios (BPR), milling speed, milling time, and milling environment. It also analyzes different papers based on the Cu-based particle generation route, including pretreatment, mechanical milling, approach (top-down or bottom-up), and post-treatment. The review further discusses characterization methods for the obtained CuP and CuC from mechanical milling.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Engineering, Chemical
Mehnaz Mursalat, Mirko Schoenitz, Edward L. Dreizin, Aurelien Neveu, Filip Francqui
Summary: Spherical boron powders with sizes ranging from 4 to 100 μm were prepared by ball milling a commercial boron powder, with a narrow size distribution. Fragile spherical particles showed improved mechanical stability when a fluorocarbon binder was added. Adjusting milling parameters could alter the size distribution of the formed spheres.
Article
Chemistry, Inorganic & Nuclear
A. Krishnanunni, Akshayakumar Kompa, Dhananjaya Kekuda, M. S. Murari, K. Mohan Rao
Summary: This study investigates the impact of defects on the magnetic behavior of ZnO based samples, specifically Co-Sm co-doped ZnO nano powder. The results show that the prepared samples exhibit wurtzite phase with enhanced defects on doping and co-doping. The presence of defects in the samples enhances their magnetic behavior.
INORGANIC CHEMISTRY COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Abdel Khaleq Mousa Alsmadi, Belal Salameh, Maryam Barhoush
Summary: In this study, high-quality copper-doped ZnO films were prepared using the standard spray pyrolysis method. The correlation between magnetic ordering and native defect states in the ZnO lattice was systematically investigated. The results showed that the detected ferromagnetic ordering is intrinsic and induced by the copper dopants. An improvement in ferromagnetic ordering was observed with increasing copper dopant concentration, which was correlated with an increase in oxygen vacancy and zinc interstitial concentrations and a slight decrease in the concentration of zinc vacancies and oxygen interstitial levels. The magnetic ordering mechanism was associated with the long-range ferromagnetic coupling between copper ions mediated by intrinsic defects.
Article
Chemistry, Physical
Yang Gao, Zhizheng Rong, Peng Du, Dejian Sun, Ka Gao, Linan An
Summary: This study prepared a 5 vol% Al2O3 nanoparticles reinforced 6061 Al matrix nanocomposite by mechanical alloying and hot-pressing. The effect of milling time on the morphology of powder and the microstructure and mechanical properties of nanocomposites was investigated. The results showed that milling time influenced the mechanical properties through the distribution of Al2O3 nanoparticles in the Al matrix. A longer milling time was required to achieve uniform dispersion of Al2O3 nanoparticles within Al grains, resulting in improved mechanical properties. The nanocomposite prepared with 50 hours of milling exhibited a tensile strength of 602 MPa and an elongation to failure of 8.8%, which were higher than those of similar materials reported previously.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Inorganic & Nuclear
Salma Alshehri, Samar Al-Shehri, Haitham Ali, Ali Abdel-Daiem Hassaneen, Mohammed Salah Aida
Summary: Undoped and Ca-doped ZnO nanoparticles were synthesized via hydrothermal method. The influence of Ca doping ratio on the physical properties of ZnO nanoparticles was investigated by varying the Ca doping ratio. XRD and SEM techniques were used for structural and morphological characterization, while transmittance measurements were used for optical characterization. It was found that the introduction of Ca in the ZnO network enlarged the crystallographic parameters, created tensile strain, and increased the crystallite size. The prepared nanopowder showed homogeneously distributed spherical grains with increasing Ca doping ratio. The optical band gap of Ca-doped ZnO decreased due to the increase in crystallite size and disorder creation.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Physics, Condensed Matter
Kapil Y. Salkar, R. B. Tangsali, R. S. Gad
Summary: Monophasic In(2-x)NdxO3 nanoparticle samples with cubic bixbyite structure were prepared using auto-combustion method. Increasing Nd3+ concentration led to an increase in lattice constant 'a' and cell volume 'V', as well as a decrease in crystallite size 't'. Scanning Electron Micrographs showed spherical particle formation, while Energy dispersive X-ray spectroscopy confirmed the presence of In, Nd and O in the samples.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Nanoscience & Nanotechnology
Li-Fu Yi, Shintaro Kunimoto, Tomoya Ishii, Lei He, Tetsuhiko Onda, Zhong-Chun Chen
Summary: This study proposed a novel method to prepare Al/Mg2Si composites, which involved the synthesis of Mg2Si particles by solid-state reactions and subsequent mechanical milling. The results showed that as the milling time increased, the size of Mg2Si particles in the composites became smaller, while the grain sizes of the Al matrix remained unchanged. The hot-extrusion process eliminated particle agglomerations and promoted size reduction and uniform dispersion of Mg2Si particles. The composites exhibited increased mechanical properties with increasing milling time, but decreased elongation. The hot-extruded Al/Mg2Si composites showed high strength and ductility compared to conventionally cast composites.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Ceramics
Wenli Yang, Fernando D. Cortes Vega, Kamyar Ahmadi, Arti Rani, Viktor G. Hadjiev, Hector A. Calderon, Stanko R. Brankovic, Francisco C. Robles Hernandez
Summary: In this work, we achieved bandgap tuning of pseudoboehmite through high energy ball milling. The crystallite size of pseudoboehmite increased with milling time, while the d-spacing decreased in the c-axis direction and increased in the a-b directions. XPS and EELS analyses showed a bandgap tuning effect in pseudoboehmite after 10 hours of milling.
CERAMICS INTERNATIONAL
(2022)
Article
Engineering, Chemical
Mirko Schoenitz, Kerri Lee A. Chintersingh, Edward L. Dreizin
Summary: Emulsion-assisted milling is used to produce spherical composite powders for various applications. This study focuses on correlating milling process parameters with the characteristics of the spherical powders produced. By varying the milling conditions, spherical powders were obtained and classified based on their shape and size. The quality of the powders was evaluated using a parameter called Q, which is maximized when a large fraction of spherical particles with a narrow size distribution is produced. A correlation was found between Q and a combined milling process parameter, and the conditions leading to the formation of high-quality spherical powders also resulted in material refinement.
Article
Engineering, Electrical & Electronic
Muhammad Adil Mahmood, Khaled Althubeiti, Sherzod Sh. Abdullaev, Nasir Rahman, Mohammad Sohail, Shahid Iqbal, Kashif Safeen, Akif Safeen, Aurangzeb Khan, Rajwali Khan
Summary: ZnO nanotubes doped with Co and Gd were studied for their structural, magnetic, and dielectric properties. Co and Gd doping reduced the crystallization rate while maintaining optimal symmetry. The morphology of the nanotubes remained unaffected by the doping. Increasing Gd co-doping resulted in higher dielectric constant and dielectric loss values. Doping showed an inverse relationship with the dielectric constant and ac electrical conductivity. At 4% co-doping, ferromagnetic characteristics were observed in the nanotubes. Increasing Gd co-doping beyond this point resulted in a reduced ferromagnetic reaction. The electrical conductivity of Zn0.92Co0.04Gd0.04O nanotubes was superior to pure and less co-doped ZnO. These nanotubes have potential applications in spintronics.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Physics, Applied
Yang Yang, Peng Zhang, Su-Huai Wei
Summary: The study using HSE06 hybrid functional revealed that ferromagnetism induced by cation vacancies in Zn chalcogenides is possible, with FM coupling between individual vacancies lowering energy. Furthermore, the FM coupling increases gradually from ZnO to ZnS and ZnSe, suggesting a higher likelihood of room-temperature ferromagnetism in ZnS and ZnSe compared to ZnO.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Rajwali Khan, Ihab Shigidi, Sattam Al Otaibi, Khaled Althubeiti, Sherzod Shukhratovich Abdullaev, Nasir Rahman, Mohammad Sohail, Alamzeb Khan, Shahid Iqbal, Tommaso Del Rosso, Quaid Zaman, Aurangzeb Khan
Summary: In this study, the co-precipitation approach was used to synthesize ZnO, Zn0.96Gd0.04O, and Zn0.96-xGd0.04CoxO nanotubes. The effects of gadolinium and cobalt doping on the microstructure, morphology, and optical characteristics of ZnO were investigated. It was found that gadolinium and cobalt doping did not affect the morphology of the nanotubes, but reduced the crystallinity of the samples. The doping also resulted in changes in the optical characteristics and electrical conductivity of the nanotubes.
Article
Chemistry, Physical
Yow-Jon Lin, Hsing-Cheng Chang, C. Y. Chuang, Ping-En Lu, Jing-Shiuan Huang
Summary: This study investigates the effect of graphene addition on the electrical and ferromagnetic properties of ZnO thin films. The results show that graphene doping increases the hole concentration in the thin film and enhances the intensity of the ferromagnetic signal.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
