Conveners
Physics of Condensed Matter and Materials
- J.J Terblans
Physics of Condensed Matter and Materials
- Hasani Chauke
Physics of Condensed Matter and Materials
- Thulani Jili (University of Zululand)
Physics of Condensed Matter and Materials
- Khomotso Maenetja (University of Limpopo)
Physics of Condensed Matter and Materials
- Lehlohonolo Lisema (School of Physics, University of the Witwatersrand, Johannesburg, 2050, South Africa)
Physics of Condensed Matter and Materials
- Motlalepula Rebecca Mhlongo (Sefako Makgatho Health Sciences University)
Physics of Condensed Matter and Materials
- Peace Mkhonto (University of Limpopo)
Physics of Condensed Matter and Materials
- Mubarak Yagoub (University of Johannesburg)
Physics of Condensed Matter and Materials
- Daniel Wamwangi (School of Physics, University of the Witwatersrand)
Physics of Condensed Matter and Materials
- J.J Terblans
Physics of Condensed Matter and Materials
- R.E. Kroon (Department of Physics, University of the Free State)
Physics of Condensed Matter and Materials
- Robert Warmbier (University of the Witwatersrand)
Carbon nanotubes (CNTโs) have a variety of different uses, in nanoscience and nanotechnology, such as energy storage, device modelling, automotive parts, thin-film electronics etc. Due to the large range of applications understanding the characteristics and typical behaviour of these materials becomes important. In realistic systems, CNTโs will contain defects such as adatoms and vacancies and...
Interest in utilizing solid materials for hydrogen storage has grown in recent years due to the necessity of reducing greenhouse gas emissions by harnessing hydrogen as an energy source. While this approach is generally regarded as safe, significant challenges remain in developing materials that are effective, easily synthesized, cost-efficient, highly stable, and exhibit rapid sorption...
The concept of a local energy density in a many-electron system has been a topic of discussion and debate for over 30 years. Chetty and Martin conducted the initial research in this field in the early 1990s, expanding upon the quantum mechanical stress theorem that Nielsen and Martin had derived in 1985. In the research that they conducted in 1992, Chetty and Martin introduced the idea of...
The current work focuses on the properties of MgFe2O4, Ni0.5Mg0.5Fe2O4, and NiFe2O4 nanoparticles synthesized via the glycothermal reaction method. The product compounds were characterized for structural, morphology, optical, and magnetic properties using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Transmission electron microscopy (TEM), Scanning electronic...
This study presents a comprehensive comparative analysis of pure and rare earth (RE)-substituted spinel ferrites, including ZnFeโOโ, CoFeโOโ, Znโ.โโ Coโ.โโ FeโOโ, and their Gdยณโบ- and Ndยณโบ-substituted counterparts, synthesized via the glycothermal method. The substitution of RE ions at Feยณโบ octahedral sites was employed to investigate their impact on the structural, physicochemical, and gas...
Cermets are composite materials that exhibit a unique combination of mechanical and physical properties that favour their application as cutting and wear resistant tools. The tuning of properties for performance is dependent on the interactions between the refractory metal and the magnetic binder. In this work, magnetic, electrical and thermal properties of Fe-based Niobium Carbide cermets...
The rare-earth germanates has attracted significant attention due to their remarkable thermal stability, low phonon energy, and structural flexibility, making them promising hosts for rare-earth ion doping in photonic and optoelectronic applications. Yttrium pyrogermanate (Y2Ge2O7) phosphors were synthesized via the solid-state reaction method and doped with...
Biomimetic coatings, an innovative advancement in biomedical engineering, replicate the complex mechanisms and properties observed in biological systems to enhance the performance, durability, reliability, and biocompatibility of biomedical implants [1-2]. These coatings aim to improve implant integration with the human body, addressing the challenges of traditional coatings like thermally...
In this study, Eu3+ (fixed at 1 mol.%) activated Zn4B6O13 phosphors incorporated with metal ions of different oxidation states Mx+ (x = 1 - 4) were successfully prepared by combustion synthesis method using urea as a fuel. Partial substitution of metal ions with varying oxidation states enhanced the luminescence properties of...
The discovery of half-metallic property in the ferromagnetic compound Co2MnZ (Z = Al, Sn) by Ishida et al. [1] and Kรผbler et al. [2] has prompted an extensive search for new Co2YZ materials that exhibit the half-metallic ferromagnetic (HMF) property. Half-metallic ferromagnets are characterized by the presence of a gap at the Fermi energy...
High entropy alloys (HEAs) are a new class of materials that exhibit promising structural and functional properties, particularly in the field of hydrogen storage. However, the materials and methods used for hydrogen storage currently pose challenges, resulting in the limited storage capacity. Refractory elements are identified as potential candidates for developing effective materials for...
Polycrystalline SiC samples were implanted at 350 ยฐC with 360 keV Ag ions (Ag-SiC), and some of the Ag-SiC samples were co-implanted with 17 keV He ions (Ag+He-SiC). The Ag-SiC and Ag+He-SiC samples were annealed isochronally at 1000 to 1300 ยฐC in steps of 100 ยฐC for 5 h. Before and after annealing, samples were characterized using Raman spectroscopy, transmission electron microscopy (TEM),...
ThCr$_2$Si$_2$-type (space group: $I$4/$mmm$) materials have attracted a significant amount of interest in recent years because of the intriguing ground states and structure-property relationships exhibited by them. In particular, the $A$Mn$_2$Ge$_2$ ($A$ = alkaline earth metal or rare-earth metal) compounds have been shown to exhibit a wide variety of complex magnetic structures and unusual...
Alloying chromium-nickel with cobalt (Co), and manganese (Mn) offers the possibility of creating alloys with high yield strength and fracture toughness, while alloying chromium-nickel with aluminum (Al) also contributes yield strength and fracture toughness, along with low density. This study probed the phase composition and microstructure of the low entropy CrNiX system by considering X = Co,...
Fluorine-doped tin oxide (FTO) is an n-type semiconductor transparent conducting oxide (TCO) widely adopted for various applications, including gas sensors, digital displays, touch switches, optical windows, and electrochromic applications. To investigate its suitability for optoelectronic applications in the Low Earth Orbit (LEO) environment, FTO thin films were exposed to different fluences...
Zinc stannate (ZnSnOโ) is a wide-bandgap oxide semiconductor with considerable potential for application in solar energy conversion devices, such as dye-sensitized solar cells (DSSCs). However, its practical use is limited by its low visible spectrum absorption. The current study investigates the Zn-site partial doping with transition metals specifically Cu, Ni, and Co effect on the electronic...
Cellulose is an important natural material, which is biocompatible and hydrophobic, and can form strong and stable stiff-chain monomolecular structures with film and hydrogel-forming properties. The focus of this investigation was to develop a mixed nano-materials sheet, which can be used as a gas sensor system. The Microcellulose sheet was treated with TEMPO...
Two dimensional (2D) materials have gained a very dominating position in the world of quantum materials due to their high potential for advanced applications in flexible electronics, optoelectronics, energy storage, catalysis, spintronics etc. An enormous playground exists in developing 2D van der Waals heterostructure by combining a variety of 2D materials for realising extraordinary...
Abstract
Incorporating nitrogen atoms into gallium arsenide (GaAs) significantly reduces the band gap, primarily due to a downward shift in the conduction band edge. This distinctive characteristic of gallium arsenide nitride (GaAsN) and other III-V-N alloys makes them promising candidates for various applications in semiconductor electronics, such as solar cells and telecommunication laser...
The development of electric vehicles and smart devices has been the primary driver of the rapid growth of the global market for lithium-ion batteries (LIBs). However, they suffer from challenges of safety, narrow electrochemical windows, and long-life cycles, which are ascribed to the usage of liquid electrolytes. The Li9Al3(PO4)2(P2O7)3 material is among the potential replacements for...
Keletso Monareng1, Petros Ntoahae1, and Rapela Maphanga2,3
1Department of Physics, University of Limpopo, Private bag x 1106, Sovenga, 0727, Polokwane, South Africa
2Next Generation Enterprises and Institutions, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria, 0001, South Africa
3 National Institute for Theoretical and Computational Sciences, NITheCS, Gauteng, 2000,...
The evolution and progress of humanity have a significant connection to our energy consumption practices. Reliable energy sources are essential for promoting economic expansion, particularly as modern society becomes ever more energy dependent. The rapid development of zinc-air batteries (ZABs) is leading them to be seen as promising alternatives to traditional lithium-ion batteries for energy...
Pyrochlore oxides are fascinating class of materials known for their remarkable thermal stability and adaptability, making them excellent candidates for energy-related applications. In this study we explore the effects of thermal treatment on structural, morphological, optical, thermodynamic and magnetic properties of CeโZrโOโ nanoparticles (CZONPs) prepared using sol-gel method and then...
{In$_x$Ga$_{1-x}$N} is a semiconductor widely used in optoelectronics$^1$. Significant advancements are being made to semiconducting materials to enhance their properties. One noteworthy approach is doping InGaN with silicon Si. Photoluminescence studies were conducted on samples with 10% In concentration, both with and without silicon (Si) doping. Earlier literature indicates that introducing...
Semiconductor heterostructures have been pivotal in the progress of electronic and optoelectronic devices. A notable category within this realm is the type II band alignment, where optically excited electrons and holes localise in separate material layers. The distinctive properties exhibited by two-dimensional transition metal dichalcogenides, coupled with the potential for engineering van...
Titanium carbide (Ti3C2Tx) MXenes have emerged as promising materials for gas sensing due to their unique two-dimensional structure, high surface area, metallic conductivity, and tunable surface chemistry. These properties enable efficient interaction with gas molecules, even at the physisorption level, resulting in significant shifts in electrical parameters. Unlike traditional semiconductor...
This study investigates the influence of substrate geometry on the microstructural evolution, phase stability, and biological response of air plasma-sprayed hydroxyapatite (HAp) coatings on Ti-6Al-4V alloy substrates. Coatings were applied under atmospheric conditions onto three geometrically distinct substrates: flat disks, thick cylinders, and cylindrical rods, followed by immersion in...
Most materials expand upon heating due to the anharmonic nature of lattice vibrations. However, some exhibit the rare phenomenon of volume contraction with increasing temperature, known as negative thermal expansion (NTE). Even rarer are zero thermal expansion (ZTE) materials, which show negligible dimensional changes with temperature. ZTE materials hold significant technological promise,...
Recent studies has shown that buried amorphous carbon layers in diamond created by ion implantation have Seebeck behaviours that can be attributed to the graphitic assembly of the carbon bonds. The extent of the sp2 carbon network is clearly attributed to the fluence and annealing cycle used. In these buried layers we observe the shift of the minimum of the Seebeck voltage amplitude to higher...
Photocatalysis using titanium dioxide nanomaterial remains one of the most promising technologies for sustainable and environmental remediation. Because of their morphology (i.e. a high surface area), nanostructured TiO2 nanotubes have been actively studied due to their potential use in photocatalytic applications.
In this work, anodic TiO2 nanotubes are used as photocatalysts for the...
Due to its negative impact on semiconductor devices, iron (Fe) is one of the most thoroughly investigated impurities in silicon. It is a usual unintended impurity in silicon manufacturing, functioning as a fast diffuser and severely lowering carrier lifetimes, especially harmful for solar cells applications. It is still unclear how defects or other impurities interact with substitutional and...
Over the years, the study of bent and curved geometries in nanomaterials [1] has remained of great interest to researchers, as it provides a new platform for investigating fundamental physical properties such as mechanical deformation led generation of pseudo-electric and magnetic fields [2,3] or introducing strain via curvature-induced molecular adsorbates on a graphene sheet [4]. However,...
Most monoatomic paramagnetic metals show a monotonic increase in electrical resistivity $\rho$ with increase in temperature $T$. This behavior can be quite efficiently described by Bloch-Grรผneissen (BG) model of conduction carrier scattering from acoustic phonons. The scope of the BG model that leads to a linear $\rho(T)$ at sufficiently high temperatures and $\rho \propto T^5$ at low...
In this work, we use Rutherford Backscattering Spectrometry (RBS) to investigate the effect of chlorine (Cl) content on the morphology and the crystal structure of tin-doped mixed halide perovskite films. A chemical vapor deposition (CVD) system was used to grow lead-tin (Pb-Sn) halide films using lead chloride (PbCl2) and tin chloride (SnCl2) precursor materials. These films were subsequently...
The layered ThCr$_2$Si$_2$-type tetragonal compound, SrCo$_2$As$_2$ shows antiferromagnetic fluctuations, which are believed to be a precursor for superconductivity in the iron-arsenide family. However, the co-existence of ferromagnetic (FM) fluctuations likely precludes a superconducting ground state in this compound. Hence, it is important to investigate whether chemical doping suppresses FM...
Materials with ThCr2Si2-type crystal structure (Space Group: I4/mmm) have sparked scientific interest for several decades now owing to their novel properties and exotic ground states. The ThCr2Si2-type compounds have physical properties that are highly tunable, making this family of compounds ideal for investigating the structure-property...
High temperature shape memory alloys (HTSMAs) are smart materials with unique ther-momechanical characteristics that can regain their original shape after deformation. HTSMAs have been used in a wide range of industrial applications, thus include actuators in automobiles, aviation parts in aerospace and biomedical equipment. Ti-based alloys such as NiTiPd, NiTiPd and NiTiFe have lower...
This study reports on the structural, electronic, dynamical, mechanical, thermodynamic, and thermoelectric properties of SnSb as a possible material for harvesting waste-heat energy. Complementary ab-initio density functional theory (DFT) and experimental studies have been carried-out to evaluate the thermoelectric performance of SnSb in the NaCl-type structure via the figure of merit, $ZT$....
The current paradigm of discovering, designing and optimising new materials from first-principles simulation can be prohibitively expensive to simulate. Despite the growth in popularity of machine learning to accelerate first principles design and optimisation of materials, data scarcity (Experimental and/or simulated) still poses a challenge. In this study, Physics-Informed Message Passing...
The Diamond Light Source is an X-ray synchrotron light source in the United Kingdom with over 30 beamlines. The beamline i13-1 is an imaging beamline that takes advantage of the coherence of the coherent X-ray beam produced. Bragg coherent diffraction imaging (BCDI) and Ptychography are the main techniques available at i13-1 which has a an experimental station that is 220 m from the undulator...
