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Influence of Cu doping in Magnesium Hydroxide Nanoparticles for Bandgap Engineering

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Journal of Wuhan University of Technology(Materials science) 2023年第3期38卷 485-489页

作者： sYED Masood Raza s naseem shah ADEEL Tahir YAsMEEN Bibi Department of Physics Federal Urdu University of ArtsScience&TechnologyKarachiPakistan Department of Chemistry Federal Urdu University of ArtsScience&TechnologyKarachiPakistan

Cu doped Mg(OH)_(2) nanoparticles were synthesized with varying concentrations from 0 to 10%by a chemical synthesis technique of coprecipitation.X-rays diffraction (XRD) of the samples confirms that all the samples acquire the hexagonal crystal *** results indicated the solubility limit of dopant in the host material and the secondary phase of CuO was observed beyond 3%Cu doping in Mg(OH)_(2).The reduction in the size of nanoparticles was observed from 166 to 103 nm for Mg(OH)_(2) and 10% Cu doped Mg(OH)_(2)samples,*** shift in absorption spectra exhibited the systematical enhancement in optical bandgap from 5.25 to 6.085 eV.A good correlation was observed between the bandgap energy and crystallite size of the nanocrystals which confirmed the size induced effect in the *** transformation in the sample morphology was observed from irregular spherical particles to sepals like shapes with increasing the Cu concentration in the host *** energy dispersive X-Ray (EDX) analysis confirmed the purity of mass percentage composition of the elements present in the samples.

关键词： Cu doped Mg(OH)_(2) nanoparticles phase purity optical band gap morphologies

Large scale silver nanowires network fabricated by MeV hydrogen (H＋) ion beam irradiation

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Chinese Physics B 2016年第4期25卷 268-273页

作者： Honey s naseem s Ishaq A Maaza M Bhatti M T Wan D Center of Excellence in solid state Physics University of the Punjab Lahore Pakistan National Center for Physics Quaid-i-Azam University Islamabad 44000 Pakistan UNEsCO-UNIsA Africa Chair in Nanosciences/Nanotechnology College of Graduate Studies University of South Africa Muckleneuk ridge P. O. Box 392 Pretoria South Africa Nanosciences African Network (NANOAFNET) iThemba LABS National Research Foundation Old Faure road P. O. Box 722 Somerset West 7129 South Africa Department of Physics Bahauddin Zakariya University Multan 60800 Pakistan school of Materials science and Engineering Shanghai University Shanghai 201900 China

A random two-dimensional large scale nano-network of silver nanowires （Ag-NWs） is fabricated by MeV hydrogen （H＋） ion beam irradiation. Ag-NWs are irradiated under H＋ ion beam at different ion fluences at room temperature. The Ag-NW network is fabricated by H＋ ion beam-induced welding of Ag-NWs at intersecting positions. H＋ ion beam induced welding is confirmed by transmission electron microscopy （TEM） and scanning electron microscopy （sEM）. Moreover, the structure of Ag NWs remains stable under H＋ ion beam, and networks are optically transparent. Morphology also remains stable under H＋ ion beam irradiation. No slicings or cuttings of Ag-NWs are observed under MeV H＋ ion beam irradiation. The results exhibit that the formation of Ag-NW network proceeds through three steps： ion beam induced thermal spikes lead to the local heating of Ag-NWs, the formation of simple junctions on small scale, and the formation of a large scale network. This observation is useful for using Ag-NWs based devices in upper space where protons are abandoned in an energy range from MeV to GeV. This high-quality Ag-NW network can also be used as a transparent electrode for optoelectronics devices.

关键词： Ag nanowires H+ ion irradiation nanowelding large scale nano-network optical properties

structural,electronic,and magnetic properties of Co-doped ZnO

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Chinese Physics B 2012年第9期21卷 414-421页

作者： Bakhtiar Ul Haq A. Afaq R. Ahmed s. naseem Center of Excellence in solid state Physics University of the Punjab Quid-e-Azam CampusLahore-54590 Pakistan Department of Physics Faculty of Science Universiti Teknologi Malaysia Skudai Johar Malaysia Center of Excellence in solid state Physics University of the Punjab Quid-e-Azam Campus Lahore-54590 Pakistan

Density functional theory based calculations have been carried out to study structural, electronic, and magnetic properties of Znl-xCoxO （x = 0, 0.25, 0.50, 0.75） in the zinc-blende phase, and the generalized gradient approximation proposed by Wu and Cohen has been used. Our calculated lattice constants decrease while the bulk moduli increase with the increase of Co2＋ concentration. The calculated spin polarized band structures show the metallic behavior of Co-doped ZnO for both the up and the down spin cases with various doping concentrations. Moreover, the electron population is found to shift from the Zn-O bond to the Co-O bond with the increase of Co2~ concentration. The total magnetic moment~ the interstitial magnetic moment, the valence and the conduction band edge spin splitting energies, and the exchange constants decrease, while the local magnetic moments of Zn, Co, O, the exchange spin splitting energies, and crystal field splitting energies increase with the increase of dopant concentration.

关键词： density functional theory magnetic semiconductors generalized gradient approximation

Effect of Cu/Zn substitution in MgO Nanostructures for Tuning the Optical Bandgap and structural Properties

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Journal of Wuhan University of Technology(Materials science) 2022年第6期37卷 1035-1040页

作者： ATIF Dawar s naseem shah M AsIF siddiqui YAsMEEN Bibi Department of Physics Federal Urdu University of ArtsScience and TechnologyKarachiPakistan Department of Chemistry Federal Urdu University of ArtsScience and TechnologyKarachiPakistan

Low cost co-precipitation method was used to synthesize Cu(0-0.05)doped MgO samples with fixed concertation of Zn=0.01.X-ray diffraction(XRD)spectra confirmed the phase purity of the samples for 0≤Cu≤0.03 doping *** secondary phase for 0.04≤Cu≤0.05 exhibited the formation of mixed metal *** crystallite size was found to increase from 17.5 to 23.5 nm for 0≤Cu≤0.03 and then decreased from 22 to 18.5 nm for 0.04≤Cu≤*** estimated bandgap first reduced from 5.48 to 4.88 eV and then increased from 5.21 to 5.36 *** morphology of the samples transformed from spheroidal shape to star-like *** obtained results reveal that the structural and optical property are in good agreement with the morphological *** peak shifting towards the lower values of vibrational frequency from 694 to 579 cm^(-1) confirms the incorporation of Cu/Zn in Mg-O *** tuning of optical bandgap and structural properties with varying dopant concentration in MgO nanomaterials can be used for multifunctional modern energy storage and optoelectronic devices.

关键词： Cu/Zn doping MgO optical bandgap morphology vibrational modes

structural and dielectric study of nano-crystalline single phase sn1-xNixs(XNi=0-10%) showing room temperature ferromagnetism

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Progress in Natural science:Materials International 2017年第3期27卷 303-310页

作者： B.Parveen M.Hassan s.Atiq s.Riaz s.naseem M.Asif Toseef Materials Growth and simulation Laboratory Department of PhysicsUniversity of the Punjab Centre of Excellence in solid state Physics University of the Punjab Department of Physics Govt. Islamia College

sns is a promising Ⅳ-Ⅵ semiconductor,which is very less explored for diluted magnetic semiconducting and dielectric *** this study,the Ni doping(xNi=0-10mol%) effects on sns host lattice were investigated.A simple and low cost co-precipitation technique was employed to grow Ni doped sns *** X-ray diffraction confirmed single phase orthorhombic structure with a nano-crystalline nature that was further verified through the surface structure observed by scanning electron *** edge x-ray absorption fine structure spectroscopy revealed a shift in the Ni absorption edge towards higher energy,depicting the formation of Ni+3oxidation *** impedance measurements,in the frequency range 1 kHz to 20 MHz,depict that owing to the excellent sensitivity to the electromagnetic radiations at the low energy,the Ni doped sns finds potential applications in various energy related *** sample magnetometer measurements have elucidated room temperature ferromagnetism,which depicts potential memory device applications.

关键词： Diluted magnetic semiconductors Room temperature ferromagnetism Near edge x-ray absorption fine structure spectroscopy Dielectric properties Co-precipitation method

Fabrication of Amorphous silver Nanowires by Helium Ion Beam Irradiation

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Chinese Physics Letters 2015年第9期32卷 93-95页

作者： shehla H. Ali A. Zongo s. Javed I. Ishaq A. Khizar H. naseem s. Maaza M. National Center for Physics Quaid-i-Azam University Islamabad 44000 Pakistan Center of Excellence in solid state Physics University of the Punjab Lahore Pakistan UNEsCO-UNIsA Africa Chair in Nanosciences/Nanotechnology College of Graduate Studies University of South Africa Muckleneuk ridge Pretoria-South Africa Nanosciences African Network (NANOAFNET) iThemba LABS-National Research Foundation 10ldFaure road Somerset West 7129 South Africa Laboratory of Nanoscience and Technology Department of Physics International Islamic University Islamabad Pakistan Department of Physics Mirpur University of Science and Technology Mirpur Azad Jammu & Kashmire

Amorphous silver nanowires （a-Ag NWs） are fabricated from crystalline Ag NWs by using 5 MeV helium （He＋） ion beam irradiation. At low dose （5 × 1015 ion/cm2）, few defects are created in Ag NWs. As dose increases, more damage to the crystalline structure of Ag NWs is observed. Finally at high dose （8 × 1016 ion/cm2）, the face-centered cubic structure of Ag NWs is transformed into the amorphous structure with similar morphology as Ag NWs. Phase transformation of crystalline Ag NWs upon irradiation with 5 MeV He＋ ions is observed through high resolution transmission electron microscopy. synthesis of large scale amorphous metal nanowires and metal nanowire alloy systems are discussed.

关键词： Ag

Plasmon-Enhanced Upconversion Fluorescence in Er^(3+):Ag Phosphate Glass:the Effect of Heat Treatment

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Chinese Physics Letters 2013年第2期30卷 182-185页

作者： Raja J.Amjad M.R.sahar s.K.Ghoshal M.R.Dousti s.Riaz A.R.samavati M.N.A Jamaludin s.naseem Advanced Optical Material Research Group Faculty of ScienceUniversiti Teknologi Malaysia81310 SkudaiJohorMalaysia Centre for solid state Physics University of the PunjabQACLahore-54590Pakistan

The melt quenching method is used to prepare erbium-doped silver nanoparticle(NP)embedded phosphate *** effect of annealing on the glass on the formation of silver NPs produced by the reduction of silver(Ag^(+)→Ag^(o))is *** glass samples are characterized by x-ray diffraction,UV-vis-NIR absorption,photoluminescence spectroscopy and transmission electron microscopy(TEM)*** absorption spectra reveal not only the peaks due to Er^(3+)ions,but also the surface plasmon resonance band of silver NPs located around~442 *** TEM imaging shows the homogeneous distribution of silver NPs of almost spherical shape with an average diameter of~5 *** luminescence spectra show two major emissions at 550 and 638 nm,originating from the 4s_(3/2)and 4F_(9/2)energy levels of the Er^(3+)ions,*** enhancement in the luminescence intensity of both the green and red bands is found to be due to the effective local field of the silver NPs as well as the energy transfer from the nanoclusters,comprised of centers with silver ions bound to silver atoms in dimers or trimers to Er^(3+)ions,whereas quenching occurred due to the energy transfer from erbium ions to silver NPs(Er^(^(3^(+)))→Ag^(o)).

关键词： silver quenching luminescence

BER Performance of space-Time Coded MMsE DFE for Wideband Code Division Multiple Access (WCDMA)

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International Journal of Communications, Network and system sciences 2009年第4期2卷 276-282页

作者： sanjay Kumar sHARMA s. naseem AHMAD Dept. of Electronics and Communication Engg Jamia Millia Islamia Delhi India Dept. of Electronics and Communication Engg. Krishna Institute of Engg. and Technology Ghaziabad India

In recent times, there has been growing interests in integration of voice, data and video traffic in wireless communication networks. With these growing interests, WCDMA has immerged as an attractive access technique. The performance of WCDMA system is deteriorated in presence of multipath fading environment. The paper presents space-time coded minimum mean square error (MMsE) Decision Feedback Equalizer (DFE) for wideband code division multiple access (WCDMA) in a frequency selective channel. The filter coefficients in MMsE DFE are optimized to suppress noise, intersymbol interference (IsI), and multiple access interference (MAI) with reasonable system complexity. For the above structure, we have presented the estimation of BER for a MMsE DFE using computer simulation experiments. The simulation includes the effects of additive white Gaussian noise, multipath fading and multiple access interference (MAI). Furthermore, the performance is compared with standard linear equalizer (LE) and RAKE receiver. Numerical and simulation results show that the MMsE DFE exhibits significant performance improvement over the standard linear equalizer (LE) and RAKE receiver.

关键词： Decision Feedback Equalizer Multiple Access Interference (MAI) RAKE Receiver Transmit Diversity Wideband Code-Division Multiple-Access (WCDMA) Bit Error Rate (BER)

Image Fusion Using Wavelet Transformation and XGboost Algorithm

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Computers, Materials & Continua 2024年第4期79卷 801-817页

作者： shahid naseem Tariq Mahmood Amjad Rehman Khan Umer Farooq samra Nawazish Faten s.Alamri Tanzila saba Department of Information sciences Division of S&TUniversity of EducationLahore54770Pakistan Artificial Intelligence and Data Analytics(AIDA)Lab CCIS Prince Sultan UniversityRiyadh11586Saudi Arabia Faculty of Information sciences University of EducationVehari CampusVehari61100Pakistan Department of Computer science University of Engineering and TechnologyTaxila47050Pakistan Department of Mathematical sciences College of SciencePrincess Nourah Bint Abdulrahman UniversityRiyadh84428Saudi Arabia

Recently,there have been several uses for digital image *** fusion has become a prominent application in the domain of imaging *** create one final image that provesmore informative and helpful compared to the original input images,image fusion merges two or more initial images of the same *** fusion aims to produce,enhance,and transform significant elements of the source images into combined images for the sake of human visual *** fusion is commonly employed for feature extraction in smart robots,clinical imaging,audiovisual camera integration,manufacturing process monitoring,electronic circuit design,advanced device diagnostics,and intelligent assembly line robots,with image quality varying depending on *** research paper presents various methods for merging images in spatial and frequency domains,including a blend of stable and curvelet transformations,everageMax-Min,weighted principal component analysis(PCA),HIs(Hue,Intensity,saturation),wavelet transform,discrete cosine transform(DCT),dual-tree Complex Wavelet Transform(CWT),and multiple wavelet *** fusion methods integrate data from several source images of an identical target,thereby enhancing information in an extremely efficient *** precisely,in imaging techniques,the depth of field constraint precludes images from focusing on every object,leading to the exclusion of certain *** tackle thess challanges,a very efficient multi-focus wavelet decomposition and recompositionmethod is *** use of these wavelet decomposition and recomposition techniques enables this method to make use of existing optimized wavelet code and filter *** simulated outcomes provide evidence that the suggested approach initially extracts particular characteristics from images in order to accurately reflect the level of clarity portrayed in the original *** study enhances the performance of the eXtreme Gradient Boosting(XGBoos

关键词： Image fusion max-min average CWT XGBoost DCT inclusive innovations spatial and frequency domain