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M. Hussein N. Assadi

M. Hussein N. Assadi
RIKEN | RIKEN AICS · Quantum Information Electronics Division

PhD

About

96
Publications
12,438
Reads
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1,192
Citations
Introduction
Physicist, interested in applying a combination of first-principles and phenomenological theoretical methods to understand and manipulate the electronic properties of functional materials (husseinassadi.com).
Education
August 2007 - April 2011
UNSW Sydney
Field of study
  • Material Science and Engineering

Publications

Publications (96)
Article
We demonstrate the significance of the Fock exchange in accurately describing dopant geometry on the superexchange interaction between the magnetic ions in doped semiconductors. The result emphasizes the important role of the Coulombic and electronic contributions to the Hellmann-Feynman forces, which have been overlooked in methods using generaliz...
Article
Template-directing strategies for synthesising metal–organic frameworks (MOFs) have brought about new frontiers in materials chemistry due to the possibility of applying control over crystal growth, morphology and secondarily generated pores. In particular, hard templates have resulted in performance breakthroughs in catalysis, secondary ion batter...
Article
Full-text available
Holey 2D metal oxides have shown great promise as functional materials for energy storage and catalysts. Despite impressive performance, their processing is challenged by the requirement of templates plus capping agents or high temperatures; these materials also exhibit excessive thicknesses and low yields. The present work reports a metal‐based co...
Article
Green rust (GR) is a mixed-valent iron mineral and structurally constitutes a family of layered double hydroxides that have attracted widespread attention in environmental and energy applications. However, despite the ubiquity of GR in environments and its potential instrumental role in life’s emergence, its instability against oxidation has limite...
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Full-text available
Through comprehensive density functional calculations, we demonstrate oxygen's significant participation in the redox reaction in a Na excess NaxRuO3 cathode material. The availability of O electrons for the redox reaction originates from the local coordination environment. For high sodium content (x ≈ 2), O ions in the layered hexagonal Na2RuO3 co...
Preprint
Full-text available
Using density functional calculations, we examine insertion/extraction of Mg ions in Mg3Bi2, an interesting Mg-ion battery anode. We found that a (1 1 0) facet is the most stable termination. Vacating a Mg2+ ion from the octahedral site is more favourable for both surface and bulk regions of the material. However, the diffusion barriers among the t...
Article
Perovskite multiferroics have drawn significant attention in the development of next-generation multifunctional electronic devices. However, the majority of existing multiferroics exhibit ferroelectric and ferromagnetic orderings only at low temperatures. Although interface engineering in complex oxide thin films has triggered many exotic room-temp...
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Full-text available
Using density functional calculations, we examine insertion/extraction of Mg ions in Mg3Bi2, an interesting Mg-ion battery anode. We found that a (110) facet is the most stable termination. Vacating a Mg²⁺ ion from the octahedral site is more favourable for both surface and bulk regions of the material. However, the diffusion barriers among the tet...
Article
We show here that MOF-5, a sample Zn-based MOF, can uniquely transform into distinct zinc oxide nanostructures. Inspired by the interconversion synthesis of zeolites, we converted MOF-5 into nanocrystalline ZnO. We found the conversion of MOF-5 into ZnO to be tunable and straightforward simply by controlling the treatment temperature and choosing a...
Article
Full-text available
Using density functional calculations, we examine insertion/extraction of Mg ions in Mg3Bi2, an interesting Mg-ion battery anode. We found that a (110) facet is the most stable termination. Vacating a Mg²⁺ ion from the octahedral site is more favourable for both surface and bulk regions of the material. However, the diffusion barriers among the tet...
Preprint
Full-text available
The scarcity of fossil fuels as carbon resources has motivated the steelmaking industry to search for new carbon sources such as end-of-life polymeric products. Using $\textit{ab initio}$ molecular dynamics simulation, we demonstrate that 41% of polycarbonate's carbon content is readily dissolved in molten iron's interface at $T$ = 1823 K which is...
Preprint
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Using molecular dynamics simulation, we present a comprehensive study of the volatile thermal degradation of high-density polyethylene (HDPE) across a temperature range of 300 K to 1823 K. We find that degradation at temperatures higher than $\sim$ 1373 K generates significant quantities of reducing gases such as CH$_{\text{n}}$ and hydrogen molecu...
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Layered double hydroxides (LDHs) constitute a unique group of 2D materials that can deliver exceptional catalytic, optical, and electronic performance. However, they usually suffer from low stability compared to their oxide counterparts. Using density functional calculations, we quantitatively demonstrate the crucial impact of the intercalants (i.e...
Preprint
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Through comprehensive density functional calculations, we predict the stability of a rhenium-based ferrite
Preprint
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The significance of the spin-orbit interaction is very well known in compounds containing heavier elements such as the rare-earth Eu ion. Here, through density functional calculations, we investigated the effect of the spin-orbit interaction on the magnetic ground state of Eu doped magnetite ($\mathrm{Fe_3O_4:Eu_{Fe}}$). By examining all possible s...
Article
Full-text available
Through comprehensive density functional calculations, we predict the stability of a rhenium-based ferrite, ReFe2O4, in a distorted spinel-based structure. In ReFe2O4, all Re and half of the Fe ions occupy the octahedral sites while the remaining Fe ions occupy the tetrahedral sites. All Re ions are predicted to be at a + 4 oxidation state with a l...
Article
Full-text available
The significance of the spin–orbit interaction is very well known in compounds containing heavier elements such as the rare-earth Eu ion. Here, through density functional calculations, we investigated the effect of the spin–orbit interaction on the magnetic ground state of Eu doped magnetite (Fe3O4:EuFe). By examining all possible spin alignments b...
Chapter
Over the past 20 years, sodium cobaltate (NaxCoO2) has been considered a front-runner for medium and high-temperature thermoelectric applications. As common with all thermoelectric materials, tens of different dopants have so far been examined to improve the thermoelectric efficiency of sodium cobaltate. However, progress has remained incremental....
Preprint
Full-text available
Doping is considered to be the main method for improving the thermoelectric performance of layered sodium cobaltate (Na$_{1-x}$CoO$_2$). However, in the vast majority of past reports, the equilibrium location of the dopant in the Na$_{1-x}$CoO$_2$'s complex layered lattice has not been confidently identified. Consequently, a universal strategy for...
Preprint
Full-text available
Environmental concerns are the chief drive for more innovative recycling techniques for end-of-life polymeric products. One attractive option is taking advantage of C and H content of polymeric waste in steelmaking industry. In this work, we examined the interaction of two high production polymers, i.e., polyurethane and polysulfide with molten iro...
Article
Designing an excellent solar photocatalyst based on TiO2 without an external cocatalyst such as Pt remains unresolved despite its exceptional potential for renewable energy production. Here, we report a state-of-the-art solar-driven photocatalytic Cl-doped rutile TiO2, in nanosheet morphology with (110) facets, for H2 production from water splittin...
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Full-text available
Microporous organosilicas assembled from polysilsesquioxane (POSS) building blocks are promising materials that are yet to be explored in-depth. Here, we investigate the processing and molecular structure of bispropylurea bridged POSS (POSS-urea), synthesised through the acidic condensation of 1,3-bis(3-(triethoxysilyl)propyl)urea (BTPU). Experimen...
Preprint
Full-text available
The water gas shift reaction (WGS) is important and widely applied in the production of H2. Cu modified perovskites are promising catalysts for WGS reactions in hydrogen generation. However, the structure-dependent stability and reaction pathways of such materials remain unclear. Herein, we report catalytically active Cu modified SrTiO3 (nominally...
Article
The thermoelectric effect allows direct and reversible conversion of thermal energy into electricity. As a result, thermoelectric generators and coolers can be an essential part of the solution to today’s energy challenges by reducing adverse effects on the environment. Nonetheless, further progress in thermoelectric research critically depends on...
Article
Full-text available
Microporous organosilicas assembled from polysilsesquioxane (POSS) building blocks are promising materials that are yet to be explored in-depth. Here, we investigate the processing and molecular structure of bispropylurea bridged POSS (POSS-urea), synthesised through the acidic condensation of 1,3-bis(3-(triethoxysilyl)propyl)urea (BTPU). Experimen...
Article
Full-text available
A water-gas shift reaction (WGS) is important and widely applied in the production of H2. Cu-modified perovskites are promising catalysts for WGS reactions in hydrogen generation. However, the structure-dependent stability and reaction pathways of such materials remain unclear. Herein, we report catalytically active Cu-modified SrTiO3 (nominally Sr...
Preprint
Full-text available
High-performance thermoelectric oxides could offer a great energy solution for integrated and embedded applications in sensing and electronics industries. Oxides, however, often suffer from low Seebeck coefficient when compared with other classes of thermoelectric materials. In search of high-performance thermoelectric oxides, we present a comprehe...
Article
Full-text available
Reducing our overwhelming dependence on fossil fuels requires groundbreaking innovations in increasing our efficiency in energy consumption for current technologies and moving towards renewable energy sources. Thermoelectric materials can help in achieving both goals. Moreover, because of recent advances in high-performance computing, researchers m...
Article
We synthesized a new organosiloxane bridge on the basis of an isocyanurate derivative through a simple melt-fusion approach by the reaction of 3-isocyanatopropyltriethoxysilane (IPTES) with 1,3,5-tris(2-hydroxyethyl)-1,3,5-triazinane-2,4,6(1H,3H,5H)-trione (THEIC). The obtained carbamate-isocyanurate-based organosiloxane bridge precursor was used f...
Article
Full-text available
High-performance thermoelectric oxides could offer a great energy solution for integrated and embedded applications in sensing and electronics industries. Oxides, however, often suffer from low Seebeck coefficient when compared with other classes of thermoelectric materials. In search of high-performance thermoelectric oxides, we present a comprehe...
Preprint
The interplay between covalency and magnetism is non-trivial and can be harnessed for designing new functional magnetic materials. Based on a survey using density functional calculations, we show that $TM\unicode{x2013}O$ bond covalency can increase the total magnetic moment of spinel compounds of $TMFe_2O_4$ composition ($TM = V-Ni, Nb-Pd$) which...
Preprint
Full-text available
Designing high potential cathodes for Na-ion batteries, which are comparable in performance to Li-ion cathodes, remains a challenging task. Through comprehensive density functional calculations, we disentangle the relationship between the cathode potential and the ionicity of $TM-O$ bonds in $O3$ $NaTMO_2$ compounds in which TM ions is a fourth- or...
Preprint
Full-text available
Molecular dynamics simulation is used to study vacancy cluster formation in $\beta$- and $\alpha$-$Si_3N_4$ with varying vacancy contents (0 - 25.6 at%). Vacancies are randomly created in supercells, which were subsequently heat-treated for 114 nanoseconds. The results show that both $\beta$ and $\alpha$ can tolerate vacancies up to 12.8 at% and fo...
Article
Full-text available
Molecular dynamics simulation is used to study vacancy cluster formation in β-and α-Si3N4 with varying vacancy contents (0-25.6 at%). Vacancies are randomly created in supercells, which were subsequently heat-treated for 114 ns. The results show that both β and α can tolerate vacancies up to 12.8 at% and form clusters, confirming previous experimen...
Article
Full-text available
Precise control over the morphology of nanomaterials is critical yet challenging. Here, we report an efficient approach to tailor the architecture of nanostructures. The process involves rapid disassembly/reassembly of an unstable metal-based coordination polymer (MCP) by controlling the kinetics of the reassembly process. The synthesis procedure d...
Article
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We examined the electronic property of Sb-doped Na0.785CoO2 using density functional calculations based on GGA+U formalism. We demonstrated that Sb dopants were the most stable when replacing Co ions within the complex Na0.875CoO2 lattice structure. We also showed that the SbCo dopants adopted the + 5 oxidation state introducing two electrons into...
Article
Full-text available
Electron beam induced etching (EBIE) has recently emerged as a promising direct-write nanofabrication technique. EBIE is typically assumed to proceed entirely through chemical pathways driven by electron-electron interactions. Here we show that knock-on (i.e., momentum transfer from electrons to nuclei) can play a significant role in EBIE, even at...
Article
Full-text available
Doping has been extensively used as the main strategy for improving the thermoelectric performance of sodium cobaltate (NaxCoO2). Here, by examining the formation energy of Hf dopant in Na0.75CoO2, we demonstrate that under Na and O rich environments, Hf replaces a Co while in all other conditions Hf replaces a Na. We then discuss the critical depe...
Article
Identifying high-voltage cathode materials is critically important for increasing the energy density of Na ion batteries. Through a comprehensive density-functional survey, we demonstrate that oxygen redox in R3¯ (ilmenite structure) Na1MO3 generates high operating voltage upon extraction and insertion of a Na ion. In the R3¯ structure, O ions are...
Article
Full-text available
In article number 1905288, Sajjad S. Mofarah, Esmaeil Adabifiroozjaei, Pramod Koshy, and co‐workers present a versatile metal‐based coordination strategy to fabricate stratified structures. These structures are readily exfoliated into ultrathin holey nanosheets of metal oxides. The holey architecture of the nanosheets minimizes the diffusion distan...
Article
Full-text available
Sourcing our ever-increasing demand for energy to power our high-paced and energy-thirsty industries poses a never-ending challenge. Therefore, many academic, industrial, and government entities put forward tremendous efforts in search of clean and sustainable energy resources. Taking into account the availability, safety, and efficiency of formic...
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Full-text available
Hydroxyapatite (HA) is one of the basic materials in the construction of the bones. In this study, we investigate the new Nano-architecture of HA in a polymer base material like PLA to 3d printing of the bones. We have introduced a simple soft-template approach for Nano-plates from HA. HA nanostructure has been produced which has a thickness and di...
Article
Full-text available
Doping is considered to be the main method for improving the thermoelectric performance of layered sodium cobaltate (Na1-xCoO2). However, in the vast majority of past reports, the equilibrium location of the dopant in the Na1-xCoO2' complex layered lattice has not been confidently identified. Consequently, a universal strategy for choosing a suitab...
Article
Mesoporous aluminosilica is a unique structure for catalysis due to Lewis acidity of aluminum. Here, we design a new catalyst by merging periodic mesoporous organosilica with aluminosilica into its structure instead of mere silica. The employed organosilica bridge in this synthesis is a thiourea based organosiloxane precursor which has a unique fea...
Article
The synthesis of mesoporous organosilicas (MOs) using co-condensation for a high ratio of a long and flexible chained organosiloxane bridge with silica precursor (e.g. tetraethylorthosilicate (TEOS)) is a complex and challenging task. By complementing the experimental characterisations with density functional calculations, The critical ratio of the...
Article
Full-text available
The design of hydroxyapatite (HA) nanoarchitecture is critical for fabricating artificial bone tissues as it dictates the biochemical and the mechanical properties of the final product. Herein, we incorporated a simple hard-template approach to synthesise single crystal nanoplates of HA. We used the 2D graphitic nitride (g-C3N4) material to prepare...
Article
Full-text available
The design of hydroxyapatite (HA) nanoarchitecture is critical for fabricating artificial bone tissues as it dictates the biochemical and the mechanical properties of the final product. Herein, we incorporated a simple hard-template approach to synthesise single crystal nanoplates of HA. We used the 2D graphitic nitride (g-C3N4) material to prepare...
Article
Full-text available
The hydrophobicity of CeO2 surfaces is examined here. Since wettability measurements are extremely sensitive to experimental conditions, we propose here a general approach to obtain contact angles between water and ceria surfaces of specified orientations based on density functional calculations. In particular, we analysed the low index surfaces of...
Article
Full-text available
The interplay between covalency and magnetism is non-trivial and can be harnessed for designing new functional magnetic materials. Based on a survey using density functional calculations, we show that TM-O bond covalency can increase the total magnetic moment of inverse spinel compounds of TMFe 2 O 4 composition (TM = V-Ni, Nb-Pd) which are isomorp...
Article
Full-text available
A zwitterionic amino acid-like N-propyliminodiacetic acid (PIDA) organocatalyst supported to a heterogeneous surface (SBA-15/PIDA) based on iminodiacetic acid and mesoporous SBA-15, respectively was synthesized. The mesoporous hybrid catalyst was successfully characterized by SEM, TEM, TGA, FTIR, and EDS and employed in the three-component reaction...
Article
Na is a probable alternative for Li in rechargeable batteries due to its lower cost and higher abundance. Na, however, has a larger ionic radius and smaller ionisation potential compared to Li. Given these shortcomings, to design a Na ion based cathode material comparable in performance to Li, all mechanisms that may increase the capacity and volta...
Article
Full-text available
Resorting to oxygen redox in addition to that of transition metal in oxide cathode materials can increase the capacity of rechargeable Na ions batteries. Through comprehensive density functional calculations, we demonstrate dominant oxygen participation in the redox reaction in cation disordered hexagonal and ordered monoclinic polymorphs of Na 2 −...
Article
This work for the first time unfurls a novel room temperature time-effective concept to manipulate the crystallization kinetics and magnetic response of thin films grown on amorphous substrate. Conventionally, metal induced crystallization is adopted to minimize the crystallization temperature of the upper-layer thin film. However, due to the limit...
Article
Full-text available
We used density functional theory approach, with the inclusion of a semiempirical dispersion potential to take into account van der Waals interactions, to investigate the water adsorption and dissociation on cobalt sulfide Co9S8 and Co3S4(100) surfaces. We first determined the nanocrystal shape and selected representative surfaces to analyze. We th...
Article
Full-text available
Utilising reversible oxygen redox in Na and transition metal oxides offers unprecedented opportunities for the design of high voltage, high capacity and affordable cathodes for application in rechargeable Na-ion batteries. Through a judicious materials search and theoretical investigations, we identified new compounds with excellent energy storage...
Article
Full-text available
Designing high potential cathodes for Na-ion batteries, which are comparable in performance to Li-ion cathodes, remains a challenging task. Through comprehensive density functional calculations, we disentangle the relationship between the cathode potential and the ionicity of TM–O bonds in O3 NaTMO2 compounds in which TM ions is a fourth- or fifth-...
Article
Full-text available
The interplay between the coordination environment and magnetic properties in O3 layered sodium transition metal oxides (NaTMO2) is a fascinating and complex problem. Through detailed and comprehensive density functional investigations on O3 NaTMO2 compounds, we demonstrate that the TM ions in O3 NaMnO2, NaFeO2 and NaCoO2 adopt a high spin state. S...
Article
Full-text available
We theoretically investigated the electronic, electrochemical and magnetic properties of Sb doped NaxCoO2 (x = 1, 0.75 and 0.50). SbCo dopants adopt 5+ oxidation state in NaxCoO2 host lattice for all Na concentrations (x). Due to high oxidation states, Sb⁵⁺ strongly repels Na ions and therefore it decreases the Na⁺/Na electrochemical potential. The...
Article
Full-text available
The effect of Ru doping on the magnetic coupling among Co ions and on the Seebeck effect in Na0.5CoO2 was systematically studied using density functional theory. It was found that the Ru dopant takes the 4+ oxidation state and replaces a Co(4+) ion. In addition, the remaining Co(4+) ions in Na0.5CoO2:Ru were stabilized in a low spin state. Magnetic...
Article
Full-text available
Using density functional theory, we calculated the formation energy of native point defects (vacancies, interstitials and antisites) in MAX phase Ti2GeC and Ti3GeC2 compounds. Ge vacancy with a formation energy of 2.87 eV was the most stable defect in Ti2GeC while C vacancy with a formation energy of 2.47 eV was the most stable defect in Ti3GeC2. G...