The improvisation of graphene oxide (GO)nanosheets by metal nanoparticles without any alterations on the sp2 network helps to enhance the surface enhanced Raman spectroscopy (SERS)effect. Herein, we describe a novel synthesis pathway to produce gold-graphene oxide (Au-GO) nanohybrid via pulsed laser ablation in liquid (PLAL). The gold nanoparticles (Au NP) decorated GO layers via PLAL are extremely pure without any surfactants and other chemical contaminants. The Optical and morphological studies were performed to validate the in situ loading of Au NPs on the GO sheets. Remarkably, these nanohybrids can act as an outstanding SERS platforms for sensing applications.
{"title":"Au-GO nanohybrids as SERS platforms fabricated via pulsed laser ablation","authors":"Parvathy Nancy, Sabu Thomas, N. Kalarikkal","doi":"10.1063/5.0061284","DOIUrl":"https://doi.org/10.1063/5.0061284","url":null,"abstract":"The improvisation of graphene oxide (GO)nanosheets by metal nanoparticles without any alterations on the sp2 network helps to enhance the surface enhanced Raman spectroscopy (SERS)effect. Herein, we describe a novel synthesis pathway to produce gold-graphene oxide (Au-GO) nanohybrid via pulsed laser ablation in liquid (PLAL). The gold nanoparticles (Au NP) decorated GO layers via PLAL are extremely pure without any surfactants and other chemical contaminants. The Optical and morphological studies were performed to validate the in situ loading of Au NPs on the GO sheets. Remarkably, these nanohybrids can act as an outstanding SERS platforms for sensing applications.","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76318726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li5La2.95Eu0.05M2O12 (M= Nb, Ta) compositions with garnet structure were prepared by conventional solid state reaction technique and photoluminescence was studied. The photoluminescence disclose that the 5D0→7F2 electric dipole transition at 611 nm is predominant in both cases; a clear evidence that Eu3+ occupies a non-centrosymmetric site in these host lattices. These emission results are contrary to the reported luminescence in Y3Al5O12 (YAG). From the Eu3+ emission studies, it can be concluded that the next nearest neighbors (NNN) cations influence the Eu3+ luminescence in these garnet phases.
{"title":"Eu3+ luminescence – A local structural probe in Li5La3M2O12 (M = Nb, Ta) with garnet structure","authors":"S. A. Naidu, Hansnath Tiwari","doi":"10.1063/5.0060894","DOIUrl":"https://doi.org/10.1063/5.0060894","url":null,"abstract":"Li5La2.95Eu0.05M2O12 (M= Nb, Ta) compositions with garnet structure were prepared by conventional solid state reaction technique and photoluminescence was studied. The photoluminescence disclose that the 5D0→7F2 electric dipole transition at 611 nm is predominant in both cases; a clear evidence that Eu3+ occupies a non-centrosymmetric site in these host lattices. These emission results are contrary to the reported luminescence in Y3Al5O12 (YAG). From the Eu3+ emission studies, it can be concluded that the next nearest neighbors (NNN) cations influence the Eu3+ luminescence in these garnet phases.","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75988826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A quantitative model for size-dependent vibrational frequency of nanomaterial explained by the quasispherical approach. We studied the variation of vibrational frequency with the change in cluster size. The maximum change in vibration frequency occurs within the size D < 30 nm, cos of the large surface/volume of that size. It is demonstrated that the vibrational frequency of nanomaterials decreases by increasing the cluster size for a positive sign while it increases with increasing the size for negative sign. It is found that the vibrational frequency of Silver (Ag) nanomaterial increases rapidly in smaller cluster size and then the rate of decrement becomes slower and tends to unity on increasing the cluster size. A blue shift (material lattice is compressed the Raman shift increases so it gains energy i.e. blue shift) occurs with +ve sign due to the lattice deformation while redshift (Heating, contraction of materials leads to frequency decrease i.e. redshift) occurs with -ve sign. Therefore, we concluded that the vibrational frequency of nanomaterials does not show a universal trend with size. Reasonable agreement between the experimental data and finding of our model for vibrational frequency has been found.
{"title":"Vibrational frequency of the silver nanomaterial","authors":"M. Manu, V. Dubey","doi":"10.1063/5.0061268","DOIUrl":"https://doi.org/10.1063/5.0061268","url":null,"abstract":"A quantitative model for size-dependent vibrational frequency of nanomaterial explained by the quasispherical approach. We studied the variation of vibrational frequency with the change in cluster size. The maximum change in vibration frequency occurs within the size D < 30 nm, cos of the large surface/volume of that size. It is demonstrated that the vibrational frequency of nanomaterials decreases by increasing the cluster size for a positive sign while it increases with increasing the size for negative sign. It is found that the vibrational frequency of Silver (Ag) nanomaterial increases rapidly in smaller cluster size and then the rate of decrement becomes slower and tends to unity on increasing the cluster size. A blue shift (material lattice is compressed the Raman shift increases so it gains energy i.e. blue shift) occurs with +ve sign due to the lattice deformation while redshift (Heating, contraction of materials leads to frequency decrease i.e. redshift) occurs with -ve sign. Therefore, we concluded that the vibrational frequency of nanomaterials does not show a universal trend with size. Reasonable agreement between the experimental data and finding of our model for vibrational frequency has been found.","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87679651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Impact of doping transition metal in optically sensitive CuS with as prepared CuS","authors":"T. V. Banumathi, J. Sudha","doi":"10.1063/5.0061043","DOIUrl":"https://doi.org/10.1063/5.0061043","url":null,"abstract":"","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90435869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Barman, P. Sadhukhan, V. Singh, Pramod Bhakuni, S. Barman
We establish a method of growing epitaxial Au-Sn compound films in ultra-high vacuum by in-situ deposition of Sn on Au(111) and subsequent heat treatment by post-annealing. The composition, electronic structure, and the surface ordering of these films have been studied using x-ray photoemission spectroscopy and low energy electron diffraction (LEED). The AuSn film grows at room temperature, whereas Au-rich films with compositions ranging from Au3Sn to Au6Sn are obtained post-annealing in the temperature range of 493 to 593 K. The thickness of the film is 11 nm for AuSn, which increases to 26 nm for Au5Sn. Sharp diffraction spots in the LEED pattern are observed, establishing that the post-annealed films are epitaxial.
{"title":"In-situ growth of epitaxial Au-Sn films on Au(111): An XPS and LEED study","authors":"S. Barman, P. Sadhukhan, V. Singh, Pramod Bhakuni, S. Barman","doi":"10.1063/5.0060984","DOIUrl":"https://doi.org/10.1063/5.0060984","url":null,"abstract":"We establish a method of growing epitaxial Au-Sn compound films in ultra-high vacuum by in-situ deposition of Sn on Au(111) and subsequent heat treatment by post-annealing. The composition, electronic structure, and the surface ordering of these films have been studied using x-ray photoemission spectroscopy and low energy electron diffraction (LEED). The AuSn film grows at room temperature, whereas Au-rich films with compositions ranging from Au3Sn to Au6Sn are obtained post-annealing in the temperature range of 493 to 593 K. The thickness of the film is 11 nm for AuSn, which increases to 26 nm for Au5Sn. Sharp diffraction spots in the LEED pattern are observed, establishing that the post-annealed films are epitaxial.","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83826028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The temperature-dependent electrical resistivity (T) of ZnO nanostructures in metallic phase is analysed by Bloch-Gruneisen [BG] model and in semiconducting phase is analyzed by small polaron conduction (SPC) model. (T) shows semiconducting phase in low temperature regime, shows an absolute minimum near 180 K and increases linearly with T at high temperatures. The contributions to the resistivity by inherent acoustic phonons (ac) as well as high frequency optical phonons (op) were estimated using Bloch-Gruneisen [BG] model of resistivity. Estimated contribution to resistivity by considering both phonons i.e., ac and op and the zero limited resistivity are added with electronelectron interaction e-e to obtain the total resistivity. Resistivity in Semiconducting phase is discussed with small polaron conduction (SPC) model at low temperatures below 180 K.
{"title":"Bloch-Gruneisen and small polaron conduction model of electrical resistivity of ZnO nanostructures","authors":"Reena Solanki, S. Goyal","doi":"10.1063/5.0061081","DOIUrl":"https://doi.org/10.1063/5.0061081","url":null,"abstract":"The temperature-dependent electrical resistivity (T) of ZnO nanostructures in metallic phase is analysed by Bloch-Gruneisen [BG] model and in semiconducting phase is analyzed by small polaron conduction (SPC) model. (T) shows semiconducting phase in low temperature regime, shows an absolute minimum near 180 K and increases linearly with T at high temperatures. The contributions to the resistivity by inherent acoustic phonons (ac) as well as high frequency optical phonons (op) were estimated using Bloch-Gruneisen [BG] model of resistivity. Estimated contribution to resistivity by considering both phonons i.e., ac and op and the zero limited resistivity are added with electronelectron interaction e-e to obtain the total resistivity. Resistivity in Semiconducting phase is discussed with small polaron conduction (SPC) model at low temperatures below 180 K.","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"96 10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83459876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The quantum effects on the propagation of an intense laser beam in an inhomogeneous cold quantum plasma (CQP) is investigated. As the intensity of laser beam increases the relativistic mass effect as well ponderomotive expulsion of electron modifies the dielectric function of the medium due to which the medium exhibits nonlinearity. Quantum plasma enhances nonlinear phenomena remarkably and hence cannot be ignored when density of the plasma electrons becomes very high that is when de Broglie wavelength of charged particle is equal to or greater average interparticle distance or equivalently temperature T is less than or equal to Fermi temperature. Based on WKB and paraxial theory, the steady state solution of an intense Gaussian electromagnetic beam is studied in CQP. By employing the expression for the dielectric function of CQP, a differential equation for beam width parameter with distance of propagation is evaluated
{"title":"Focusing/defocusing of intense laser beam in cold quantum plasma","authors":"M. Varshney, Sonu Sen, P. Sen","doi":"10.1063/5.0061323","DOIUrl":"https://doi.org/10.1063/5.0061323","url":null,"abstract":"The quantum effects on the propagation of an intense laser beam in an inhomogeneous cold quantum plasma (CQP) is investigated. As the intensity of laser beam increases the relativistic mass effect as well ponderomotive expulsion of electron modifies the dielectric function of the medium due to which the medium exhibits nonlinearity. Quantum plasma enhances nonlinear phenomena remarkably and hence cannot be ignored when density of the plasma electrons becomes very high that is when de Broglie wavelength of charged particle is equal to or greater average interparticle distance or equivalently temperature T is less than or equal to Fermi temperature. Based on WKB and paraxial theory, the steady state solution of an intense Gaussian electromagnetic beam is studied in CQP. By employing the expression for the dielectric function of CQP, a differential equation for beam width parameter with distance of propagation is evaluated","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86583640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
From the first principles in the framework of the density functional theory in LDA+U approximations, the band structure, the total and partial densities of electronic states, also the spatial distribution of the electron charge density of Cu7SiS5I and Ag7SiS5I superionic crystals had been calculated. The CuAg substitution in the Cu7SiS5I and Ag7SiS5I compounds, along with an increase of the total width of the valence band, leads to a broadening and a change in the topology of the upper bond of the valence band, due to the pd-hybridization emerging between copper (silver) and sulfur atoms. It follows from the calculations of the band structure that the Cu7SiS5I compound is a direct-gap while Ag7SiS5I indirect semiconductor. Based on the data of the total and partial densities of electronic states, the contributions of atomic orbitals to crystalline ones are determined, also the data of the chemical bond formation in the crystals under discussion are obtained.
{"title":"Influence of cationic substitution on the electronic structure of Cu7SiS5I and Ag7SiS5I compounds","authors":"D. Bletskan, V. Vakulchak, V. Lisý, I. Studenyak","doi":"10.1063/5.0060902","DOIUrl":"https://doi.org/10.1063/5.0060902","url":null,"abstract":"From the first principles in the framework of the density functional theory in LDA+U approximations, the band structure, the total and partial densities of electronic states, also the spatial distribution of the electron charge density of Cu7SiS5I and Ag7SiS5I superionic crystals had been calculated. The CuAg substitution in the Cu7SiS5I and Ag7SiS5I compounds, along with an increase of the total width of the valence band, leads to a broadening and a change in the topology of the upper bond of the valence band, due to the pd-hybridization emerging between copper (silver) and sulfur atoms. It follows from the calculations of the band structure that the Cu7SiS5I compound is a direct-gap while Ag7SiS5I indirect semiconductor. Based on the data of the total and partial densities of electronic states, the contributions of atomic orbitals to crystalline ones are determined, also the data of the chemical bond formation in the crystals under discussion are obtained.","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89609356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nikita Karma, M. Saleem, Poornima Karil, N. Kaurav, H. S. Dager
In this article, we studied theBi0.9La0.1FeO3 (BLFO) and BaTiO3 (BTO) and their composite (0.85) Bi0.9La0.1FeO3-(0.15) BaTiO3 for their structural and dielectric properties. The samples were prepared via conventional solid state reaction route. The X-ray diffraction spectroscopy analysis reveals the rhombohedral crystal structure for BLFO and Cubic structure for BTO. While, Bi0.9La0.1FeO3-(0.15) BaTiO3 depicts the presence of both the phases. The compositional and morphological studyof the composite was also carried out. The frequency dependent dielectric analysis shows that the samples exhibit a good dielectric property with low loss in directric values. The ac conductivity at lower frequency shows independent of the field but after the threshold value of frequency, the conductivity increases due to hopping of charge carriers. It is concluded that the samples are promising candidates for good energy storage capability, required in storage device applications.
{"title":"A study of structure, microstructure and dielectric property of composite of la doped BiFeO3 and BaTiO3","authors":"Nikita Karma, M. Saleem, Poornima Karil, N. Kaurav, H. S. Dager","doi":"10.1063/5.0061440","DOIUrl":"https://doi.org/10.1063/5.0061440","url":null,"abstract":"In this article, we studied theBi0.9La0.1FeO3 (BLFO) and BaTiO3 (BTO) and their composite (0.85) Bi0.9La0.1FeO3-(0.15) BaTiO3 for their structural and dielectric properties. The samples were prepared via conventional solid state reaction route. The X-ray diffraction spectroscopy analysis reveals the rhombohedral crystal structure for BLFO and Cubic structure for BTO. While, Bi0.9La0.1FeO3-(0.15) BaTiO3 depicts the presence of both the phases. The compositional and morphological studyof the composite was also carried out. The frequency dependent dielectric analysis shows that the samples exhibit a good dielectric property with low loss in directric values. The ac conductivity at lower frequency shows independent of the field but after the threshold value of frequency, the conductivity increases due to hopping of charge carriers. It is concluded that the samples are promising candidates for good energy storage capability, required in storage device applications.","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88466122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effects of impurity on the growth of crystal have been the reported by many investigators. In the present study, the effect of small amount of zinc in the solution of crystallization of struvite-K crystals was studied using the SEM, FTIR and EDAX spectroscopic techniques. It was found that, the concentration and volume of zinc ions transform the morphology of struvite-K crystals. However in FT-IR spectroscopy, the vibrational frequencies observed from pure and zinc doped struvite-K crystals, the zinc doped frequencies were found to be slightly different from pure struvite-K crystals. The observed change in the vibrations of zinc doped was due to influence of zinc ions. EDAX techniques revealed that the sample was of a mixed composition.
{"title":"Effect of zinc ions on the crystallization of urinary struvite-K crystals","authors":"V. B. Suryawanshi","doi":"10.1063/5.0061175","DOIUrl":"https://doi.org/10.1063/5.0061175","url":null,"abstract":"The effects of impurity on the growth of crystal have been the reported by many investigators. In the present study, the effect of small amount of zinc in the solution of crystallization of struvite-K crystals was studied using the SEM, FTIR and EDAX spectroscopic techniques. It was found that, the concentration and volume of zinc ions transform the morphology of struvite-K crystals. However in FT-IR spectroscopy, the vibrational frequencies observed from pure and zinc doped struvite-K crystals, the zinc doped frequencies were found to be slightly different from pure struvite-K crystals. The observed change in the vibrations of zinc doped was due to influence of zinc ions. EDAX techniques revealed that the sample was of a mixed composition.","PeriodicalId":18837,"journal":{"name":"NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75648971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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