Displaying publications 41 - 60 of 118 in total

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  1. Roy S, Ramiah H, Reza AW, Lim CC, Ferrer EM
    PLoS One, 2016;11(7):e0158954.
    PMID: 27391136 DOI: 10.1371/journal.pone.0158954
    Micro-electro mechanical system (MEMS) based oscillators are revolutionizing the timing industry as a cost effective solution, enhanced with more features, superior performance and better reliability. The design of a sustaining amplifier was triggered primarily to replenish MEMS resonator's high motion losses due to the possibility of their 'system-on-chip' integrated circuit solution. The design of a sustaining amplifier observing high gain and adequate phase shift for an electrostatic clamp-clamp (C-C) beam MEMS resonator, involves the use of an 180nm CMOS process with an unloaded Q of 1000 in realizing a fixed frequency oscillator. A net 122dBΩ transimpedance gain with adequate phase shift has ensured 17.22MHz resonant frequency oscillation with a layout area consumption of 0.121 mm2 in the integrated chip solution, the sustaining amplifier draws 6.3mW with a respective phase noise of -84dBc/Hz at 1kHz offset is achieved within a noise floor of -103dBC/Hz. In this work, a comparison is drawn among similar design studies on the basis of a defined figure of merit (FOM). A low phase noise of 1kHz, high figure of merit and the smaller size of the chip has accredited to the design's applicability towards in the implementation of a clock generative integrated circuit. In addition to that, this complete silicon based MEMS oscillator in a monolithic solution has offered a cost effective solution for industrial or biomedical electronic applications.
    Matched MeSH terms: Electronics, Medical*
  2. Alam MJ, Ahamed E, Faruque MRI, Islam MT, Tamim AM
    PLoS One, 2019;14(11):e0224478.
    PMID: 31714917 DOI: 10.1371/journal.pone.0224478
    Interferences and accuracy problem are one of the most talked issues in today's world for sensor technology. To deal with this contention, a microstrip framework consisting of a dual mode double negative (DNG) metamaterial based bandpass filter is presented in this article. To obtain the ultimate noise reduction bandpass filter, the proposed structure has to go through a series of development process, where the characteristics of the structure are tested to the limit. This filter is built on Rogers RT-5880 substrate with a 50Ω microstrip line. To pursue the elementary mode of resonant frequency, the ground layer of the structure is kept partially filled and a gradual analysis is executed on the prospective metamaterial (resonator) unit cell. Depending on the developed unit cell, the filter is constructed and fabricated to verify the concept, concentrating on GPS (1.55GHz), Earth Exploration-Satellite (2.70GHz) and WiMAX (3.60GHz) bands of frequencies. Moreover, the structure is investigated using Nicolson-Ross-Weir (NRW) approach to justify the metamaterial characteristics, and also tested on S-parameters, current distribution, electric and magnetic fields and quality factor. Having a propitious architecture and DNG characteristics, the proposed structure is suitable for bandpass filter for GPS, Earth Exploration-Satellite and WiMAX frequency sensing applications.
    Matched MeSH terms: Electronics
  3. Chuan MW, Wong KL, Riyadi MA, Hamzah A, Rusli S, Alias NE, et al.
    PLoS One, 2021;16(6):e0253289.
    PMID: 34125874 DOI: 10.1371/journal.pone.0253289
    Silicene has attracted remarkable attention in the semiconductor research community due to its silicon (Si) nature. It is predicted as one of the most promising candidates for the next generation nanoelectronic devices. In this paper, an efficient non-iterative technique is employed to create the SPICE models for p-type and n-type uniformly doped silicene field-effect transistors (FETs). The current-voltage characteristics show that the proposed silicene FET models exhibit high on-to-off current ratio under ballistic transport. In order to obtain practical digital logic timing diagrams, a parasitic load capacitance, which is dependent on the interconnect length, is attached at the output terminal of the logic circuits. Furthermore, the key circuit performance metrics, including the propagation delay, average power, power-delay product and energy-delay product of the proposed silicene-based logic gates are extracted and benchmarked with published results. The effects of the interconnect length to the propagation delay and average power are also investigated. The results of this work further envisage the uniformly doped silicene as a promising candidate for future nanoelectronic applications.
    Matched MeSH terms: Electronics
  4. Bakar AA, Lim YL, Wilson SJ, Fuentes M, Bertling K, Taimre T, et al.
    Physiol Meas, 2013 Feb;34(2):281-9.
    PMID: 23363933 DOI: 10.1088/0967-3334/34/2/281
    Optical sensing offers an attractive option for detection of surface biopotentials in human subjects where electromagnetically noisy environments exist or safety requirements dictate a high degree of galvanic isolation. Such circumstances may be found in modern magnetic resonance imaging systems for example. The low signal amplitude and high source impedance of typical biopotentials have made optical transduction an uncommon sensing approach. We propose a solution consisting of an electro-optic phase modulator as a transducer, coupled to a vertical-cavity surface-emitting laser and the self-mixing signal detected via a photodiode. This configuration is physically evaluated with respect to synthesized surface electrocardiographic (EKG) signals of varying amplitudes and using differing optical feedback regimes. Optically detected EKG signals using strong optical feedback show the feasibility of this approach and indicate directions for optimization of the electro-optic transducer for improved signal-to-noise ratios. This may provide a new means of biopotential detection suited for environments characterized by harsh electromagnetic interference.
    Matched MeSH terms: Electronics/instrumentation*
  5. Fum WKS, Wong JHD, Tan LK
    Phys Med, 2021 Apr;84:228-240.
    PMID: 33849785 DOI: 10.1016/j.ejmp.2021.03.004
    PURPOSE: This systematic review aims to understand the dose estimation approaches and their major challenges. Specifically, we focused on state-of-the-art Monte Carlo (MC) methods in fluoroscopy-guided interventional procedures.

    METHODS: All relevant studies were identified through keyword searches in electronic databases from inception until September 2020. The searched publications were reviewed, categorised and analysed based on their respective methodology.

    RESULTS: Hundred and one publications were identified which utilised existing MC-based applications/programs or customised MC simulations. Two outstanding challenges were identified that contribute to uncertainties in the virtual simulation reconstruction. The first challenge involves the use of anatomical models to represent individuals. Currently, phantom libraries best balance the needs of clinical practicality with those of specificity. However, mismatches of anatomical variations including body size and organ shape can create significant discrepancies in dose estimations. The second challenge is that the exact positioning of the patient relative to the beam is generally unknown. Most dose prediction models assume the patient is located centrally on the examination couch, which can lead to significant errors.

    CONCLUSION: The continuing rise of computing power suggests a near future where MC methods become practical for routine clinical dosimetry. Dynamic, deformable phantoms help to improve patient specificity, but at present are only limited to adjustment of gross body volume. Dynamic internal organ displacement or reshaping is likely the next logical frontier. Image-based alignment is probably the most promising solution to enable this, but it must be automated to be clinically practical.

    Matched MeSH terms: Electronics
  6. Sathasivam, Saratha, Mustafa Mamat, Mohd Shareduwan Mohd Kasihmuddin, Mohd. Asyraf Mansor
    MyJurnal
    Clonal selection algorithm and discrete Hopfield neural network are extensively employed for solving higher-order optimization problems ranging from the constraint satisfaction problem to complex pattern recognition. The modified clonal selection algorithm is a comprehensive and less iterative immune-inspired searching algorithm, utilized to search for the correct combination of instances for Very large-scale integrated (VLSI) circuit structure. In this research, the VLSI circuit framework consists of Boolean 3-Satisfiability instances with the different complexities and number of transistors are considered. Hence, a hybrid modified clonal selection algorithm with discrete Hopfield neural network is well developed to optimize the configuration of VLSI circuits with different number of electronic components such as transistors as the instances. Therefore, the performance of the developed hybrid model was assessed experimentally with the standard models, HNNVLSI-3SATES and HNNVLSI-3SATGA in term of circuit accuracy, sensitivity, robustness and runtime to complete the verification process. The results have demonstrated the developed model, HNNVLSI-3SATCSA produced a minimum error (consistently approaching 0), better accuracy (more than 80%) and faster computational time (less than 125 seconds) against changes in the complexity in term of the number of transistors. Furthermore, the developed hybrid model is able to minimize the computational burden and configurational noises for the variant of VLSI circuits.
    Matched MeSH terms: Electronics
  7. Nima Ghamarian, Azmah Hanim, M.A., Nahavandi, M., Zulkarnain Zainal, Lim, Hong Ngee
    MyJurnal
    In the recent years, electronic packaging provides significant research and development challenges
    across multiple disciplines such as performance, materials, reliability, thermals and interconnections.
    New technologies and techniques frequently adopted can be implemented in soldering alloys of
    semiconductor sectors in terms of optimisation. Wetting contact angle or wettability of solder alloys
    is one of the important factors which has got the attention of scholars. Hence in this study, due to the
    remarkable similarity over classical solder alloys (Pb-Sn), Bi-Ag solder was investigated. Data were
    collected through the effects of aging time variation and different weight percentages of Ag in solder
    alloys. The contact angle of the alloys with Cu plate was measured by optical microscopy. Artificial
    neural networks (ANNs) were applied on the measured datasets to develop a numerical model for further
    simulation. Results of the experiments and simulations showed that the coefficient of determination (R2
    )
    is around 0.97, which signifies that the ANN set up is appropriate for the evaluation.
    Matched MeSH terms: Electronics
  8. Ali T, Jan S, Alkhodre A, Nauman M, Amin M, Siddiqui MS
    PeerJ Comput Sci, 2019;5:e216.
    PMID: 33816869 DOI: 10.7717/peerj-cs.216
    Conventional paper currency and modern electronic currency are two important modes of transactions. In several parts of the world, conventional methodology has clear precedence over its electronic counterpart. However, the identification of forged currency paper notes is now becoming an increasingly crucial problem because of the new and improved tactics employed by counterfeiters. In this paper, a machine assisted system-dubbed DeepMoney-is proposed which has been developed to discriminate fake notes from genuine ones. For this purpose, state-of-the-art models of machine learning called Generative Adversarial Networks (GANs) are employed. GANs use unsupervised learning to train a model that can then be used to perform supervised predictions. This flexibility provides the best of both worlds by allowing unlabelled data to be trained on whilst still making concrete predictions. This technique was applied to Pakistani banknotes. State-of-the-art image processing and feature recognition techniques were used to design the overall approach of a valid input. Augmented samples of images were used in the experiments which show that a high-precision machine can be developed to recognize genuine paper money. An accuracy of 80% has been achieved. The code is available as an open source to allow others to reproduce and build upon the efforts already made.
    Matched MeSH terms: Electronics
  9. Chan KG, Pawi S, Ong MF, Kowitlawakul Y, Goy SC
    Nurse Educ Pract, 2020 Oct;48:102864.
    PMID: 32920369 DOI: 10.1016/j.nepr.2020.102864
    The aim of this study was to investigate factors influencing nursing students' intention to use a simulated web-application 'Integrated Nursing Education System' for practicing electronic health documentation. The cross-sectional study was conducted at a Malaysian University that provides undergraduate nursing degree program. A total of 133 undergraduate nursing students in their year 2 to year 4 of the program were recruited. They had accessed the simulated web-application as part of the teaching-learning activities during the academic year 2016/2017. Technology Acceptance Model was used to guide the study. Validated questionnaires were used to measure the students' perceived ease of use, perceived usefulness, attitudes and intention to use the application. Data collection was done at the end of the semester. Data analysis was done using SPSS (19.0) and AMOS (23.0). Perceived usefulness was the most influential factor of the students' intention to use the simulated web-application. Perceived ease of use influenced their perceived usefulness significantly. Nurse educators should explain the usefulness of the simulated web-application before assigning students to access it to practice electronic health documentation. The availability of a stable internet access and IT support is important to influence students' perceived ease of use and intention to use the application.
    Matched MeSH terms: Electronics
  10. Sathian B, Asim M, Banerjee I, Roy B, Pizarro AB, Mancha MA, et al.
    Nepal J Epidemiol, 2021 Mar;11(1):959-982.
    PMID: 33868742 DOI: 10.3126/nje.v11i1.36163
    Background: To date, there is no comprehensive systematic review and meta-analysis to assess the suitability of COVID-19 vaccines for mass immunization. The current systematic review and meta-analysis was conducted to evaluate the safety and immunogenicity of novel COVID-19 vaccine candidates under clinical trial evaluation and present a contemporary update on the development and implementation of a potential vaccines.

    Methods: For this study PubMed, MEDLINE, and Embase electronic databases were used to search for eligible studies on the interface between novel coronavirus and vaccine design until December 31, 2020.

    Results: We have included fourteen non-randomized and randomized controlled phase I-III trials. Implementation of a universal vaccination program with proven safety and efficacy through robust clinical evaluation is the long-term goal for preventing COVID-19. The immunization program must be cost-effective for mass production and accessibility. Despite pioneering techniques for the fast-track development of the vaccine in the current global emergency, mass production and availability of an effective COVID-19 vaccine could take some more time.

    Conclusion: Our findings suggest a revisiting of the reported solicited and unsolicited systemic adverse events for COVID-19 candidate vaccines. Hence, it is alarming to judiciously expose thousands of participants to COVID-19 candidate vaccines at Phase-3 trials that have adverse events and insufficient evidence on safety and effectiveness that necessitates further justification.

    Matched MeSH terms: Electronics
  11. Dey D, De D, Ahmadian A, Ghaemi F, Senu N
    Nanoscale Res Lett, 2021 Jan 29;16(1):20.
    PMID: 33512575 DOI: 10.1186/s11671-020-03467-x
    Doping is the key feature in semiconductor device fabrication. Many strategies have been discovered for controlling doping in the area of semiconductor physics during the past few decades. Electrical doping is a promising strategy that is used for effective tuning of the charge populations, electronic properties, and transmission properties. This doping process reduces the risk of high temperature, contamination of foreign particles. Significant experimental and theoretical efforts are demonstrated to study the characteristics of electrical doping during the past few decades. In this article, we first briefly review the historical roadmap of electrical doping. Secondly, we will discuss electrical doping at the molecular level. Thus, we will review some experimental works at the molecular level along with we review a variety of research works that are performed based on electrical doping. Then we figure out importance of electrical doping and its importance. Furthermore, we describe the methods of electrical doping. Finally, we conclude with a brief comparative study between electrical and conventional doping methods.
    Matched MeSH terms: Electronics
  12. Lim XB, Ong WJ
    Nanoscale Horiz, 2021 May 21.
    PMID: 34018529 DOI: 10.1039/d1nh00127b
    The ceaseless increase of pollution cases due to the tremendous consumption of fossil fuels has steered the world towards an environmental crisis and necessitated urgency to curtail noxious sulfur oxide emissions. Since the world is moving toward green chemistry, a fuel desulfurization process driven by clean technology is of paramount significance in the field of environmental remediation. Among the novel desulfurization techniques, the oxidative desulfurization (ODS) process has been intensively studied and is highlighted as the rising star to effectuate sulfur-free fuels due to its mild reaction conditions and remarkable desulfurization performances in the past decade. This critical review emphasizes the latest advances in thermal catalytic ODS and photocatalytic ODS related to the design and synthesis routes of myriad materials. This encompasses the engineering of metal oxides, ionic liquids, deep eutectic solvents, polyoxometalates, metal-organic frameworks, metal-free materials and their hybrids in the customization of advantageous properties in terms of morphology, topography, composition and electronic states. The essential connection between catalyst characteristics and performances in ODS will be critically discussed along with corresponding reaction mechanisms to provide thorough insight for shaping future research directions. The impacts of oxidant type, solvent type, temperature and other pivotal factors on the effectiveness of ODS are outlined. Finally, a summary of confronted challenges and future outlooks in the journey to ODS application is presented.
    Matched MeSH terms: Electronics
  13. Kim HP, Vasilopoulou M, Ullah H, Bibi S, Ximim Gavim AE, Macedo AG, et al.
    Nanoscale, 2020 Apr 14;12(14):7641-7650.
    PMID: 32207472 DOI: 10.1039/c9nr10745b
    Organo-metal halide perovskite field-effect transistors present serious challenges in terms of device stability and hysteresis in the current-voltage characteristics. Migration of ions located at grain boundaries and surface defects in the perovskite film are the main reasons for instability and hysteresis issues. Here, we introduce a perovskite grain molecular cross-linking approach combined with amine-based surface passivation to address these issues. Molecular cross-linking was achieved through hydrogen bond interactions between perovskite halogens and dangling bonds present at grain boundaries and a hydrophobic cross-linker, namely diethyl-(12-phosphonododecyl)phosphonate, added to the precursor solution. With our approach, we obtained smooth and compact perovskite layers composed of tightly bound grains hence significantly suppressing the generation and migration of ions. Moreover, we achieved efficient surface passivation of the perovskite films upon surface treatment with an amine-bearing polymer, namely polyethylenimine ethoxylated. With our synergistic grain and surface passivation approach, we were able to demonstrate the first perovskite transistor with a complete lack of hysteresis and unprecedented stability upon continuous operation under ambient conditions. Added to the merits are its ambipolar transport of opposite carriers with balanced hole and electron mobilities of 4.02 and 3.35 cm2 V-1 s-1, respectively, its high Ion/Ioff ratio >104 and the lowest sub-threshold swing of 267 mV dec-1 reported to date for any perovskite transistor. These remarkable achievements obtained through a cost-effective molecular cross-linking of grains combined with amine-based surface passivation of the perovskite films open a new era and pave the way for the practical application of perovskite transistors in low-cost electronic circuits.
    Matched MeSH terms: Electronics
  14. Aziz SB, Hassan AQ, Mohammed SJ, Karim WO, Kadir MFZ, Tajuddin HA, et al.
    Nanomaterials (Basel), 2019 Feb 06;9(2).
    PMID: 30736346 DOI: 10.3390/nano9020216
    : In this work the influence of carbon nano-dots (CNDs) on absorption of ultra violet (UV) spectra in hybrid PVA based composites was studied. The FTIR results reveal the complex formation between PVA and CNDs. The shifting was observed in XRD spectrum of PVA:CNDs composites compared to pure PVA. The Debye-Scherrer formula was used to calculate the crystallite size of CNDs and crystalline phases of pure PVA and PVA:CNDs composites. The FESEM images emphasized the presence and dispersion of C-dots on the surface of the composite samples. From the images, a strong and clear absorption was noticed in the spectra. The strong absorption that appeared peaks at 280 nm and 430 nm can be ascribed to the n-π* and π-π* transitions, respectively. The absorption edge shifted to lower photon energy sides with increasing CNDs. The luminescence behavior of PVA:CNDs composite was confirmed using digital and photo luminescence (PL) measurements. The optical dielectric constant which is related to the density of states was studied and the optical band gap was characterized accurately using optical dielectric loss parameter. The Taucs model was used to determine the type of electronic transition in the samples.
    Matched MeSH terms: Electronics
  15. Yang Y, Fedorov G, Shafranjuk SE, Klapwijk TM, Cooper BK, Lewis RM, et al.
    Nano Lett., 2015 Dec 09;15(12):7859-66.
    PMID: 26506109 DOI: 10.1021/acs.nanolett.5b02564
    Van Hove singularities (VHSs) are a hallmark of reduced dimensionality, leading to a divergent density of states in one and two dimensions and predictions of new electronic properties when the Fermi energy is close to these divergences. In carbon nanotubes, VHSs mark the onset of new subbands. They are elusive in standard electronic transport characterization measurements because they do not typically appear as notable features and therefore their effect on the nanotube conductance is largely unexplored. Here we report conductance measurements of carbon nanotubes where VHSs are clearly revealed by interference patterns of the electronic wave functions, showing both a sharp increase of quantum capacitance, and a sharp reduction of energy level spacing, consistent with an upsurge of density of states. At VHSs, we also measure an anomalous increase of conductance below a temperature of about 30 K. We argue that this transport feature is consistent with the formation of Cooper pairs in the nanotube.
    Matched MeSH terms: Electronics
  16. Tawfik EA, Cartwright MS, Grimm A, Boon AJ, Kerasnoudis A, Preston DC, et al.
    Muscle Nerve, 2021 05;63(5):651-656.
    PMID: 33382094 DOI: 10.1002/mus.27163
    Neuromuscular ultrasound is a rapidly evolving specialty with direct application for patient care. Competency assessment is an essential standard needed to ensure quality for practitioners, particularly for those newly acquiring skills with the technique. Our aim was to survey experts' opinions regarding physician competency assessment of neuromuscular ultrasound and to identify minimal competency of knowledge and skills. The opinions of 18 experts were obtained through the Delphi method using two consecutive electronic surveys. A high degree of consensus was achieved on items regarding framework and the conduct of neuromuscular ultrasound assessment and the knowledge and skills that a candidate needs to attain minimal competency in neuromuscular ultrasound. In this study, a group of neuromuscular ultrasound experts developed a general framework for neuromuscular ultrasound competency assessment and recommended testable areas of knowledge and skills suitable for establishing minimal competency.
    Matched MeSH terms: Electronics
  17. Junaid M, Md Khir MH, Witjaksono G, Ullah Z, Tansu N, Saheed MSM, et al.
    Molecules, 2020 Sep 14;25(18).
    PMID: 32937975 DOI: 10.3390/molecules25184217
    In recent years, the field of nanophotonics has progressively developed. However, constant demand for the development of new light source still exists at the nanometric scale. Light emissions from graphene-based active materials can provide a leading platform for the development of two dimensional (2-D), flexible, thin, and robust light-emitting sources. The exceptional structure of Dirac's electrons in graphene, massless fermions, and the linear dispersion relationship with ultra-wideband plasmon and tunable surface polarities allows numerous applications in optoelectronics and plasmonics. In this article, we present a comprehensive review of recent developments in graphene-based light-emitting devices. Light emissions from graphene-based devices have been evaluated with different aspects, such as thermal emission, electroluminescence, and plasmons assisted emission. Theoretical investigations, along with experimental demonstration in the development of graphene-based light-emitting devices, have also been reviewed and discussed. Moreover, the graphene-based light-emitting devices are also addressed from the perspective of future applications, such as optical modulators, optical interconnects, and optical sensing. Finally, this review provides a comprehensive discussion on current technological issues and challenges related to the potential applications of emerging graphene-based light-emitting devices.
    Matched MeSH terms: Electronics
  18. Taha BA, Addie AJ, Kadhim AC, Azzahran AS, Haider AJ, Chaudhary V, et al.
    Mikrochim Acta, 2024 Apr 08;191(5):250.
    PMID: 38587660 DOI: 10.1007/s00604-024-06314-3
    Rapid technological advancements have created opportunities for new solutions in various industries, including healthcare. One exciting new direction in this field of innovation is the combination of skin-based technologies and augmented reality (AR). These dermatological devices allow for the continuous and non-invasive measurement of vital signs and biomarkers, enabling the real-time diagnosis of anomalies, which have applications in telemedicine, oncology, dermatology, and early diagnostics. Despite its many potential benefits, there is a substantial information vacuum regarding using flexible photonics in conjunction with augmented reality for medical purposes. This review explores the current state of dermal augmented reality and flexible optics in skin-conforming sensing platforms by examining the obstacles faced thus far, including technical hurdles, demanding clinical validation standards, and problems with user acceptance. Our main areas of interest are skills, chiroptical properties, and health platform applications, such as optogenetic pixels, spectroscopic imagers, and optical biosensors. My skin-enhanced spherical dichroism and powerful spherically polarized light enable thorough physical inspection with these augmented reality devices: diabetic tracking, skin cancer diagnosis, and cardiovascular illness: preventative medicine, namely blood pressure screening. We demonstrate how to accomplish early prevention using case studies and emergency detection. Finally, it addresses real-world obstacles that hinder fully realizing these materials' extraordinary potential in advancing proactive and preventative personalized medicine, including technical constraints, clinical validation gaps, and barriers to widespread adoption.
    Matched MeSH terms: Electronics
  19. Nurjuliana M, Che Man YB, Mat Hashim D, Mohamed AK
    Meat Sci, 2011 Aug;88(4):638-44.
    PMID: 21420795 DOI: 10.1016/j.meatsci.2011.02.022
    The volatile compounds of pork, other meats and meat products were studied using an electronic nose and gas chromatography mass spectrometer with headspace analyzer (GCMS-HS) for halal verification. The zNose™ was successfully employed for identification and differentiation of pork and pork sausages from beef, mutton and chicken meats and sausages which were achieved using a visual odor pattern called VaporPrint™, derived from the frequency of the surface acoustic wave (SAW) detector of the electronic nose. GCMS-HS was employed to separate and analyze the headspace gasses from samples into peaks corresponding to individual compounds for the purpose of identification. Principal component analysis (PCA) was applied for data interpretation. Analysis by PCA was able to cluster and discriminate pork from other types of meats and sausages. It was shown that PCA could provide a good separation of the samples with 67% of the total variance accounted by PC1.
    Matched MeSH terms: Electronics
  20. Zeng H, Wu M, Wang HQ, Zheng JC, Kang J
    Materials (Basel), 2020 Dec 12;13(24).
    PMID: 33322841 DOI: 10.3390/ma13245686
    The magnetic and electronic properties of boron-doped SrTiO3 have been studied by first-principles calculations. We found that the magnetic ground states of B-doped SrTiO3 strongly depended on the dopant-dopant separation distance. As the dopant-dopant distance varied, the magnetic ground states of B-doped SrTiO3 can have nonmagnetic, ferromagnetic or antiferromagnetic alignment. The structure with the smallest dopant-dopant separation exhibited the lowest total energy among all configurations considered and was characterized by dimer pairs due to strong attraction. Ferromagnetic coupling was observed to be stronger when the two adjacent B atoms aligned linearly along the B-Ti-B axis, which could be associated with their local bonding structures. Therefore, the symmetry of the local structure made an important contribution to the generation of a magnetic moment. Our study also demonstrated that the O-Ti-O unit was easier than the Ti-B-Ti unit to deform. The electronic properties of boron-doped SrTiO3 tended to show semiconducting or insulating features when the dopant-dopant distance was less than 5 Å, which changed to metallic properties when the dopant-dopant distance was beyond 5 Å. Our calculated results indicated that it is possible to manipulate the magnetism and band gap via different dopant-dopant separations.
    Matched MeSH terms: Electronics
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