Plasma Focus Devices and Application
Dense Plasma Focus (DPF) devices is a co-axial plasma accelerator which involves the storage of energy in a capacitor and pumping this energy in to a pinch plasma column during…
Energy storage devices serve as one of the essential parts for human civilization. To date, there are sufficient researches for such devices, typically, ion batteries, …
39. Exploring high entropy alloys for efficient charge to spin interconversion
Spin orbit torque-based magnetization switching is going to be the leading contender for storage and logic technologies as it offers non-volatile functionality that can scale to high density, fast speed with unlimited endurance at ultra-low power. Here, we propose new high entropy alloy (HEA) based spin Hall material (SHM) with large spin Hall angle and high spin conductivity suitable for magnetization switching. We hypothesize that the broken inversion symmetry and intra-crystal potentials created within the HEAs could provide a new intrinsic mode of spin orbit coupling (SOC). The HEAs would contain > 50% light elements like Cu, Al for high spin conductivity and magnetic (Ni, Fe, Co) and non-magnetic (Pt, Pd, Au) elements to provide spin scattering sites for improved spin Hall angle. Methodology: We plan to synthesize phase stable HEA thin films using the high energy density pulsed plasma techniques which can provide the necessary heating and cooling rates for the direct synthesis using a HEA target. The morphological, structural, chemical, magnetic, and atomistic characterization of the HEAs will be pursued. The designed HEAs will be used to investigate the charge to spin conversion using the spin torque ferromagnetic resonance technique. To understand the dominant mechanism behind the high charge to spin conversion, temperature dependent spin transport measurements will be pursued. Impact: The academic significance of the project are (1) to achieve alternative technique for the synthesis of HEAs using high energy density pulsed plasmas, (2) explore the inherent structural deformation and chemical potentials within the HEAs to achieve large spin orbit coupling, (3) achieving high spin conductivity to improve the magnetization switching efficiency. The proposed project, if successful, could open new markets for HEA based SHMs and expedite the realization of ultrafast, energy efficient SOT based magnetization switching devices.
38. Phase Locked Spin Hall Nano-Oscillators for wireless communication
Duration: 3 Years
Role: Principal Investigator
Project: MOE Tier 2 ARC 1/19 RSR
Abstract: The recent trend of 3D ultra-large-scale-integration where various systems are stacked on single IC and are interconnected with copper wires suffer from unwanted resistive and inductive losses. To overcome this issue, the implementation of wireless interconnects on 3D IC is much required solution. Nanoscale and broad-range frequency tunable Spin Hall Nano-Oscillators (SHNO) are most suitable candidates for these wireless interconnects for chip to chip wireless communication which also offers the strong compatibility with standard CMOS processing and technology. However, low output power of SHNOs still remain an open challenge. The maximum output power of SHNO is in mW range and needs to be improved to sub-mW range for chip to chip wireless communications. The key target of the project is to improve output power in the array of SHNOs by phase lock scheme using spin Hall effect and Inverse spin Hall effect in high spin-Hall materials like Pt, W and Ta. In this project, we will focus on (i) Design, fabrication and optimization of PMA based Magnetic Tunnel Junction (MTJ) with large MR ratio at low temperature < 300 °C, (ii) Charge to spin conversion in spin-Hall material (Pt/Ta/W) thin film and its integration in single SHNO, and (iii) Realization of high output power and high quality factor in PMA based phase-locked SHNOs array device.
37. Spin Orbit Coupling based IntelligencE TechnologY (SOCIETY)
Duration: 5 Years
Role: Principal Investigator
Neuromorphic computing (NC) mimics the functions of the brain using a network of synthetic neurons interconnected through synaptic devices. NC is gaining attention worldwide due to its potential for AI and big data analysis at low power. The research objectives of this programme will be aligned towards developing spin-orbit coupling based NC hardware elements, such as synthetic neurons and synaptic elements and integrating them into NC architecture for technology translation. In this proposed programme, our research and development will focus on the physics, materials science and device aspects of scalable and enduring synthetic neurons and synaptic elements based on spin-orbit coupling (SOC) and demonstration and technology translation of low-power neuromorphic computing.
36. Nanoscale plasma engineering using low- and high-temperatures plasma for energy storage/conversion and spintronics applications
Duration: 2 Years (28 Aug 2018 to 27 Aug 2020)
Role: Principal Investigator
Project: NIE RS-SAA RS 6/18 RSR
Abstract: A plasma, as compared to solid, liquid or gaseous precursors, comprises of different precursor species (molecules, atoms, and radicals) in a large number of different energetic states (ionized, excited, metastables, and ground states). The basic premise of “nanoscale plasma engineering” is that these plasma precursors can be produced, transported and self-organized to assemble/process nano-phase materials with desired chemical and physical properties that are useful for applications in energy storage/conversion and spintronics. Plasmas feature a higher degree of complexity thus allowing nanoscale synthesis, efficient doping by simple mixing of plasma precursors or by post deposition plasma treatment, defect engineering and surface nano-structuring by imping ions and plasma sheath accelerated energetic electrons. We have demonstrated fcc to fct phase transition in FePt and nitrogen ion implantation in ZnO by energetic hot dense plasma exposure for spintronics applications and plasma as tool to engineer defects, surface texturing, and doping of catalysts to achieve enhanced performance in energy conversion and storage applications. In this project, we will synthesize (i) porous nanoassemblies of hydrogen/oxygen evolution reaction (HER / OER) energy conversion materials, (ii) carbon nanomaterial supported nanoassemblies for Li and Na ion energy storage materials, and (iii) high-energy ion implanted and hot plasma processed spin-Hall materials; using different types of non-equilibrium plasmas that include RF plasmas and high energy density pinch plasmas. In order to understand plasma-surface interactions and the role of plasma in nucleation and growth, plasma diagnostics such as optical emission spectroscopy, Langmuir probe, plasma imaging etc will be employed to measure many possible plasma parameters such as plasma species, densities and temperatures. Efforts will be dedicated to develop and optimize these plasma based strategies to keep the nano-assembly synthesis to be at mild temperatures (room temperature or at least <100 °C), relatively fast (from several tens of seconds to few minutes) and for large surface area (of about 10 cm2) nanomaterial synthesis.[/bg_collapse]
35. Rashba hetero-interface designing to tune charge-spin interconversion efficiency
Duration: Three Years (2 July 2018 to 1 July 2021)
Role: Principal Investigator
Project: MOE Tier 2 ARC 1/17 RSR MOE2017-T2-2-129
Abstract:Pure spin current offers advantages of reduced power dissipation, absence of stray Oersted fields, and decoupling of spin and charge noise; making them highly suitable for magnetization direction manipulation (write operation) in spin transfer torque – magnetic random access memory (STT-MRAM) technology. Current charge to spin conversion methods have limitations. For example (i) method using exchanged coupled magnetic layer in magnetic tunnel junction suffers from very high current density (106 A/cm2) requirement, (ii) Spin Hall Effect (SHE) method in heavy metal shows limited (<33%) conversion efficiency and (iii) the orthogonal locking of electrons’ momentum and spin in topological insulators suffers from reproducibility issues. To explore innovative scheme based on Rashba Effect along with development of new material hetero interfaces, which can generate very high spin current with nearly 100% charge to spin efficiency by achieving large spin orbit interaction, needed for reliable low power magnetization switching. Large spin orbit interaction and correspondingly higher charge to spin interconversion efficiency can be achieved by appropriately designing the Rashba hetero interface along with additional control using external electric field. We will focus on (i) Rashba interface design using metal decorated graphene on epitaxial YIG/GGG system to achieve tunable spin-orbit coupling using external electric field, (ii) charge to spin interconversion efficiency measurement – using spin torque ferromagnetic resonance (ST-FMR) technique and spin-pumping through inverse Rashba Edelstein effect (IREE), and (iii) realization of magnetization Switching in magnetic layer of the fabricated device.
34. Plasma focus device and diagnostics for plasma and fusion-relevant education
Duration: Four Years (7 May 2018 to 6 May 2022)
Role: Principal Investigator
Abstract: The collaborative education, training and research have been demonstrated to have far-reaching impact and influence on scientific manpower training, technology transfer and strong research output. This has been demonstrated amply by training and collaborative activities of Asian African Association for Plasma Training (AAAPT) a group of 52 member institutes in 24 different countries. The AAAPT developed its plasma education and training programme using 3 kJ UNU/ICTP PPF (United Nations University/International Centre for Theoretical Physics Plasma Fusion Facility) specially designed for that purpose. The UNU-ICTP type PPFs, developed under AAAPT training programs, are now actively operated in several Asian and African countries and research on it has produced more than 40 PhD theses, 50 Masters theses and 400 peer reviewed research papers. A lot more needs to be done as there are several research groups in developing countries who are keen to initiate plasma fusion research using small and medium sized alternative magnetic confinement devices and they certainly are looking for opportunities for training on more updated device and diagnostics technologies. Through this CRP we wish to contribute towards that. The major aim of this CRP therefore is this project is to promote and strengthen the fusion-relevant experimental plasma education and expertise development in developing countries and research groups participating in this CRP through hands-on training and research on medium-sized mid-energy plasma focus device using array of plasma and nuclear diagnostics and material characterization techniques.
We will develop few specialized training and research modules (T&R Modules) centered around five different specialized themes for trainees with different needs. The proposed T&R Modules are as follows.
(i) T&R Module 1 – Theoretical, simulation (Lee Code) and experimental training on plasma focus device.
(ii) T&R Module 2 – Soft and Hard X-ray diagnostics training and research.
(iii) T&R Module 3 – Deuteron and Neutron diagnostics training and research.
(iv) T&R Module 4 – Optical diagnostics training and research.
(v) T&R Module 5 – Material irradiation, synthesis and characterization training and research.
These training programmes/modules can be organized independently or in combinations. For person/trainee with no background but having interest and financial backing from home university/institute in starting fusion-relevant research using plasma focus device, the basic T&R Module 1 will be conducted. While, those who already have basic ongoing research on plasma focus devices but wish to expand their research capabilities then they can work with us on T&R Modules 2 to 5. At this stage is difficult to predict who will be the trainee and which T&R Module will run under this CRP as we would like to run those modules which will be requested by more trainee or fit our on-going experimental campaign at that point of time. We would like to highlight that each training module will be focused around a research question which can be addressed alongside the training. Hence, the training will be targeted to achieve the answer to a particular research question to make the training more productive and meaningful.
33. Graphene/metal hetero-interface based optical transistors by field controlled Surface Plasmons
Duration: Three years (1 March 2018 – 28 Feb 2021)
Role: Co-Principle Investigator
Project: MOE/NTU Tier 1 (2017-T1-002-087), $150,000
32. Novel plasma synthesis and surface nanoengineering of ternary electrocatalysts
Duration: Three Years (15 Nov 2017 to 14-Nov-2020)
Role: Co-Principle Investigator
Project: MOE-Tier 2 (MOE-2017-T2-1-073), $554,623
31. Vertical Graphene based Highly-Porous High-Performance Energy Storage Nanostructured Composite Assemblies using Novel Plasma Chemistry
Duration: 2 Yrs (9 May 2017 – 8 May 2019)Principal Investigator
RI 4/16 RSR
Abstract:Many types of energy resources store energy directly into them which can be used when required e.g. energy stored in coal, oil and gas can be extracted when needed. But in many situations we do not have the control over the availability of energy as they are intermittently available, particularly for renewable energy resources such as solar, wind, tidal, hydroelectric energy. If we do not store these energies they will be wasted. There are several methods of energy storage among which electrochemical energy storage (EES) methods/systems have received considerable attention to store these intermittent renewable energy. The EES systems are not only for energy storage but also capable of delivering the easily transportable energy in portable devices such as cell phones, laptops, vehicles, electrical vehicles etc. In this grant proposal our major objective is to develop energy efficient and environmentally friendly low temperature plasma chemistry based sustainable synthesis of highly porous vertical graphene based nanostructured hybrid assemblies for high-performance high-efficiency energy storage applications in lithium ion batteries (LIBs) and supercapacitors (SCs). The project will focus on (i) sustainable and efficient synthesis of vertically-oriented graphene nano-sheets (VGNS) using various environmentally-friendly precursors at lower temperatures using novel plasma chemistry; (ii) synthesis of highly-porous nanostructured hybrid assemblies of ActMat@VGNS by loading ultra-thin nanostructured active materials (ActMat) such as silicon, MoS2, NiO etc. on the surface of vertically-oriented graphene nano-sheets, and (iii) evaluate and optimize the electrochemical performance of Si@VGNS and other hybrid assemblies (ActMat@VGNS) in LIBs and SCs configurations with an aim to achieve highest possible specific capacity/capacitance along with enhanced cyclic stability and rate capability. This research is highly timely as there is increasing emphasis and need in developing energy and resource efficient strategies to reduce the carbon footprint along with the use of sustainable resources. The proposal is highly relevant to NSSE/NIE’s goals and directions to further strengthen the ongoing research and teaching of “Clean Energy Physics” in M.Sc. (Life Science) Clean Energy Physics and is also in line with national and global emphasis on research related to various aspects of clean and green energy. The project will aim to train 1 Research Associate, 1 PhD, 1 MSc and few FYP and NRP students on clean energy related research with competency and expertise in interdisciplinary field of vacuum science, plasma science, chemical synthesis of nanomaterials, hybrid materials, diagnostics and characterization plasmas and materials; and fabrication and characterization of energy storage devices such as LIBs and SCs.
Previous Research Project
|30.||High energy density pulsed plasma based alternate carbon overcoat deposition technology to push hard disk drives storage density beyond 4 Tb/in2||1.5 Yrs (1 July 2017 – 31 Dec 2018)||Principal Investigator||
NTUitive GAP Fund-High energy density
|Abstract:Carbon overcoats (COC) play an important role in the protection of hard disk media from corrosion and mechanical wear. They play a crucial role in protecting the magnetic layers of a hard disk medium and hence the data of the users.In current technology, the carbon overcoats are about 2-3 nm thick and are made using a combination of sputtering and plasma enhanced chemical vapour deposition (PECVD). It is essential to move towards thinner carbon overcoats, but the existing technologies cannot meet the requirements at sub-2 nm.|
|29.||Deterministic Plasma Approach for Synthesis of High Performance Cost-effective Commercial Carbon-Cloth based Hybrid Assemblies for Photocatalysis||2 Yrs (01-03-17 to 28-02-19)||Principal Investigator||
MOE/NTU Tier 1
RP 4/16 RSR
|Abstract: Specific Aims and Hypotheses: The main aim of this proposal is to use appropriate plasma diagnostics to deduce the plasma chemistry in RF Plasmas processing of commercial carbon cloths to develop controlled and deterministic plasma based synthesis of highly porous nanostructurized (nitrogen/sulphur) doped carbon cloths (nDCC) which will used as electrode for transition metal – nitrides and/or -dichalcogenides to prepare cost effect hybrid light harvesting assemblies of TMNs//TMDs@nDCC for enhanced photo-catalytic performance. Methodology and Approach: The three-dimensional (3D) hierarchical nano-architecture of nDCC will be achieved via one-step nitrogen/sulfur RF plasma processing. Different parameters including flow rate, background pressure of nitrogen gas/sulfur vapor, RF plasma power and discharge duration will be optimized using optical emission spectroscopy together the characteristics of nDCC obtained.|
|28.||Voltage controlled strain-mediated magnetization switching in ferromagnetic/ferroelectric heterostructures for low power non-volatile magnetic memory||Two years (Nov 2016 to Oct 2018)||Principal Investigator||
MOE/NTU Tier 1
RP 2/16 RSR
|Abstract: Specific Aims and Hypotheses: The main aim is to investigate voltage controlled strain mediated magnetization modulation in ferromagnetic/ferroelectric (FM/FE) heterostructures for applications in low power non-volatile memories. It is hypothesized that the power consumption in strain-mediated magnetization switching will be about two orders of magnitude lower than that of the magnetization switching driven by purely current and voltage assisted current driven magnetic memories. Methodology and Approach: Firstly, a suitable FM/FE heterostructures with large Converse Magneto-Electric (CME) coupling coefficient (a=50-100 Oe-cm/kV) will be synthesized using PLD and/or DC Magnetron Sputtering.|
|27.||Synthesis and irradiation of nanostructured tungsten and carbon in plasma focus device to investigate effects of nanostructurization on recrystallization and radiation embrittlement||One year (13-11-2017 to 12-11-2018)||Principal Investigator||
|26.||Surface functionalization of nanostructured electrodes by NIE plasma for performance enhancement||2 Yrs (Oct 2015 to Sept 2017)||Co-Principal Investigator||
MOE/NTU Tier 1
|25.||Carbon-based hybrid functional nanomaterials using various plasma routes||2 Yrs (21 August 2014 to 20 August 2016)||Principal Investigator||
RP 6/14 RSR
|Hybrid functional nanomaterials are nanoscale materials with two components one which is organic and the other inorganic. They are assembled for the purpose of generating desirable properties and functionalities with twofold aim: to enhance advantageous chemical, electrochemical, magnetic or electronic characteristics and at the same time to suppress undesirable properties.|
|24.||Perfectly ordered nano-heterojunction arrays for optoelectronic applications||3 Yrs (Jan 2014 to dec 2016)||Co-Principle Investigator||MOE AcRF Tier 2 $587386 ARC23/13|
|23.||Radio Frequency and Plasma Foucs Discharge Plasmas and their Possible Applications in Material Science||3 Yrs (May 2013- April 2016)||International Collaborator||FONDECYT, CONICYT, Chile Govt Approx – S$ 365,000|
|22.||Atmospheric Microplasmas: Novel tool for Nanofabrication||4 Yrs (Feb 2012 – Jan 2016)||Principal Investigator||
RI 7/11 RSR
This project aims to conceptualize, develop and optimize various atmospheric microplasma systems (which represent a special class of electrical discharges formed in geometrics where at least one dimension is reduced to sub-millimeter length scales) for processing of thin films or bulk substrate surface; or for creating plasma discharges on liquid surfaces of electrolyte; or by using gas-plasma coupling at atmospheric condition to synthesize nanoparticles and nanophase structures on thin films or on bulk surface or in electrolytic solution or in gases.
|21.||Physics and Technology of High Repetition Rate Plasma Focus Neutron Source and Its Application in Pulsed Fast Neutron Activation Analysis||4 Yrs (Mar 2012 – Feb 2016)||Principal Investigator||
MOE/NTU Tier 1
RP 1/11 RSR
|20.||Investigations of Materials under High Repetition and Intense Fusion-relevant Pulses||3 Yrs (Feb 2012 – Feb 2015)||Principal Investigator||External, € 4500 per year by International Atomic Energy Agency, Vienna|
Abstract:One of the key issues still to be resolved in the quest for fusion energy production is the characterization, qualification (testing) and development of advanced plasma facing materials capable of withstanding the e>-ireme radiation and heat loads expected in fusion reactors.
|19.||Plasma Assisted Synthesis of Strongly Doped Diamond||1 Year (2010-11)||Co-Principal Investigator||MD-NTU/09/09 $50,000|
|18.||Design and Development of a 2.5 kJ Plasma Focus Device with Experiments on Electrical and Soft X-ray Optimizations||6 Months||Principal Investigator||
Funded by Kansas State University, USA
Abstract:The proposed project collaboration, aims to design and develop a cost-effective, single shot (0.2 Hz), low energy (2.5kJ) PF device for Department of Mechanical and Nuclear Engineering, Kansas State University (KSU) to initiate the plasma focus research under the leadership of Dr Ali Abdou.
|17.||Dilute Magnetic Semiconductor Thin Films and nanoparticle synthesis by Pulsed Laser deposition and sol-gel for Room Temperature Spintronics||3.5 Yrs (Nov 2008 to May 2012)||Principal Investigator||
RI 7/08 RSR
|16.||Low-cost polycrystalline thin film silicon solar cells using controlled high-density reactive plasma processing||4 Yrs (1 July 2008 to 30 June 2012)||Collaborator||NRF – -$1,738,425|
|15.||Novel Fusion Material Studies and Pulsed Fast Neutron Analysis using High Performance Plasma Focus Device||3 Yrs (start Feb 2008)||Co- Principal Investigator||MOE/NTU Tier 1 – RP 4/07 TTL, $100,000|
|14.||Development of MOKE Setup for measurement of magnetic properties of thin films||1 Yr (March 2007 – May 2008)||Principal Investigator||SEP: RP 13/06 RSR $27,750.60|
|13.||Neutron emission studies from miniature and medium size plasma focus device||3 Yrs (Start Nov 2006)||Principal Investigator||
MOE/NTU Tier 1: RP 3/06 RSR
AASC, US– 75,000
Abstract:There is growing need to develop neutron generators that are compact, long-lasting, efficient and inexpensive to construct and yet capable of using safe deuterium deuterium reactions to produce a high neutron yield or flux and can be tailored to meet a variety of specifications.
|12.||TEA Nitrogen Laser shadowgraphy system for current sheath investigation in Plasma Focus||3 months (Jan-April 2007)||Principal Investigator||External, ICTP, Trieste, Italy, (Euro 3000)|
|11.||Time resolved spectroscopy and imaging of pulsed laser plasma||1 Yr (Feb 2006 – Feb 2007)||Principal Investigator||SEP: RP3/05RSR, $136,185|
|10.||Development of laser and Discharge based EUV sources||1 Yr (Feb 2006 – Feb 2007)||Co Investigator||SEP: RP4/05LCK $146,055|
|9.||DPF production of Positron Emission Tomography Isotopes-Supplementary||1 Yr (Feb 2006 – Feb 2007)||Co Investigator||SEP: RP2/05SVS, $36362.40|
|8.||Development of EUV sources for nanolithography||3yr (Start Dec 2005)||Co Investigator||AcRF: RI5/05LCK, 94,366|
|7.||Neutron emission studies on plasma focus with twisted cathode geometry||6 Months (Nov 2005–May 2006)||Principal Investigator||External-AASC, US, US$5000|
|6.||Dense Plasma Focus production of Positron Emission Tomography Isotopes||3 Yrs (2005-March 2008)||Co Investigator||AcRF $160,000|
|5.||Xenon Flashtube Plasma Characterization||1 Yr (March 2005 – Feb 2006)||Principal Investigator||External (Perkin Elmer) $89,300|
|4.||Dense Plasma focus sources for intense pulsed radiation and particle beams Applications||5 Yrs (Ongoing)||Co Investigator||External IAEA $42,000|
|3.||Pulsed laser Deposition of nano-sized Cr Co/FeCo magnetic thin films||4 Yrs – (Start June 2004 – May 2008)||Principal Investigator||NIE AcRF RI7/03 RSR, $149,276|
|2.||Multiple Radiation Source||3 Yrs (2001-2004)||Co Investigator||A*Star, $500,000|
|1.||Deposition and processing of thin films using repetitive plasma focus device||3 Yrs (2001-2004)||
|NIE AcRF: RP17/00 RSR $86,583|