Browsing Det matematisk-naturvitenskapelige fakultet by Author "Vajeeston, Ponniah"

Now showing items 1-19 of 19

  • A first-principles investigation of the Li difusion mechanism in the super-ionic conductor lithium orthothioborate Li3BS3 structure 
    Bianchini, Federico; Fjellvåg, Helmer; Vajeeston, Ponniah (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2018)
  • A first-principle study of NaMPO4(M = Mn, Fe, Co, Ni) possible novelstructures as cathode materials for sodium-ion batteries: Structural andelectrochemical characterisation 
    Bianchini, Federico; Fjellvåg, Helmer; Vajeeston, Ponniah (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2018)
    Transition metal containing polyanion compounds are effective excellent electrode materials for sodium-ion batteries due to their high intrinsic electrochemical potentials and to the resulting high energy density. Iron ...
  • Anisotropy of the proton kinetic energy in ice Ih 
    Yacov, Finkelstein; Raymond, Moreh; Bianchini, Federico; Vajeeston, Ponniah (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)
    The partial vibrational density of states (pVDOS) of ice Ih, as simulated by first principle modeling based on density functional theory (DFT), is utilized for computing the Cartesian components of the proton and oxygen ...
  • Carbon-dioxide as annealing atmosphere to retain the electrical properties of indium-tin oxide 
    Mayandi, Jeyanthinath; Finstad, Terje; Venkatesan, Ragavendran; Vajeeston, Ponniah; Karazhanov, Smagul; Venkatachalapathy, Vishnukanthan (Journal article / Tidsskriftartikkel / SubmittedVersion, 2020)
    In practical applications of indium-tin-oxide (ITO) annealing at temperatures ~400 °C without degrading its electrical and optical properties is an important challenge. In the present work, commercial Indium-tin oxide (ITO) ...
  • First-Principle Calculation of High Absorption-TlGaTe2 for Photovoltaic Application 
    Rasukkannu, Murugesan; Velauthapillai, Dhayalan; Vajeeston, Ponniah (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    We use first-principle calculations based on hybrid functional and the Bethe-Salpeter equation method to investigate the electronic and optical properties of dichalcogenide TlGaTe2. Based on theoretical studies, TlGaTe2 ...
  • First-Principles Study of the Structural Stability and Dynamic Properties of Li2MSiO4 (M = Mn, Co, Ni) Polymorphs 
    Vajeeston, Ponniah; Bianchini, Federico; Fjellvåg, Helmer (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    In recent years, the scientific community has shown an increasing interest in regards to the investigation of novel materials for the intercalation of lithium atoms, suitable for application as cathodes in the new generations ...
  • High entropy alloy CrFeNiCoCu sputter deposited films: Structure, electrical properties, and oxidation 
    Mayandi, Jeyanthinath; Schrade, Matthias; Vajeeston, Ponniah; Stange, Marit Synnøve Sæverud; Lind, Anna Maria; Sunding, Martin Fleissner; Deuermeier, Jonas; Fortunato, Elvira; Løvvik, Ole Martin; Ulyashin, Alexander; Diplas, Spyridon; Almeida Carvalho, Patricia; Finstad, Terje Gunnar (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2022)
    High entropy alloy (HEA) films of CrFeCoNiCu were deposited by sputtering. Their structure was characterized and their electric transport properties were studied by temperature-dependent Hall and Seebeck measurements. The ...
  • Hybrid Density Functional Study of Au2Cs2I6, Ag2GeBaS4, Ag2ZnSnS4, and AgCuPO4 for the Intermediate Band Solar Cells 
    Rasukkannu, Murugesan; Velauthapillai, Dhayalan; Vajeeston, Ponniah (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We present a comprehensive investigation of the structural, electronic, mechanical, and optical properties of four promising candidates, namely Au2Cs2I6, Ag2GeBaS4, Ag2ZnSnS4, and AgCuPO4, for application in photovoltaic ...
  • In-depth first-principle study on novel MoS 2 polymorphs 
    Eidsvåg, Håkon; Rasukkannu, Murugesan; Velauthapillai, Dhayalan; Vajeeston, Ponniah (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Molybdenum disulphide (MoS2) is a rising star among transition-metal dichalcogenides in photovoltaics, diodes, electronic circuits, transistors and as a photocatalyst for hydrogen evolution. A wide range of MoS2 polymorphs ...
  • Insights into Crystal Structure and Diffusion of Biphasic Na2Zn2TeO6 
    Li, Xinyu; Bianchini, Federico; Wind, Julia; Pettersen, Christine; Vajeeston, Ponniah; Wragg, David; Fjellvåg, Helmer (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    The layered oxide Na2Zn2TeO6 is a fast Na+ ion conductor and a suitable candidate for application as a solid-state electrolyte. We present a detailed study on how synthesis temperature and Na-content affect the crystal ...
  • One-pot synthesis of cobalt-rhenium nanoparticles taking the unusual beta-Mn type structure 
    Zacharaki, Eirini; Bremmer, Marien G.; Vajeeston, Ponniah; Kalyva, Maria Evangelou; Fjellvåg, Helmer; Kooyman, Patricia J.; Sjåstad, Anja Olafsen (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Using a facile one-pot colloidal method, it is now possible to obtain monodisperse Co1−xRex nanoparticles (NPs), with excellent control of Re stoichiometry for x < 0.15. Re-incorporation in terms of a solid solution ...
  • Operando Investigations of Lithiation and Delithiation Processes in the BiVO4 Anode Material 
    Ruud, Amund; Sottmann, Jonas; Vajeeston, Ponniah; Fjellvåg, Helmer (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2018)
  • Pressure Dependence of Superconducting Properties, Pinning Mechanism, and Crystal Structure of the Fe0.99Mn0.01Se0.5Te0.5 Superconductor 
    Murugesan, Kannan; Lingannan, Govindaraj; Ishigaki, Kento; Uwatoko, Yoshiya; Sekine, Chihiro; Kawamura, Yukihiro; Junichi, Hayashi; Joseph, Boby; Vajeeston, Ponniah; Maheswari, Pankaj Kumar; Awana, V.P.S.; Sonachalam, Arumugam (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    We have investigated the pressure (P) effect on structural (up to 10 GPa), transport [R(T): up to 10 GPa], and magnetic [(M(T): up to 1 GPa)] properties and analyzed the flux pinning mechanism of the Fe0.99Mn0.01Se0.5Te0.5 ...
  • Pressure-dependent modifications in the LaAuSb2 charge density wave system 
    Govindaraj, Lingannan; Boby, Joseph; Vajeeston, Ponniah; Chia Nung, Kuo; Chin Shan, Lue; Ganesan, Kalaiselvan; Piu, Rajak; Sonachalam, Arumugam (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Hydrostatic pressure response of LaAuSb2 charge density wave (CDW) system is investigated using electrical transport, x-ray diffraction (XRD), and density-functional theory (DFT). Resistivity data at ambient pressure ...
  • Pressure‑induced structural transition and huge enhancement of superconducting properties of single‑crystal Fe0.99Ni0.01Se0.5Te0.5 unconventional superconductor 
    Kalaiselvan, Ganesan; Govindaraj, Lingannan; Kannan, Murugesan; Christopher S., Perreault; Gopi K., Samudrala; Pankaj Kumar, Maheshwari; V. P. S., Awana; Vajeeston, Ponniah; Yogesh K., Vohra; Sonachalam, Arumugam (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
    We report high-pressure structural studies (52 GPa) at room temperature combined with magnetic [(M(T):1GPa] and electrical resistivity [(ρ(T):0-21GPa)] measurements down to 2 K on Fe0.99Ni0.01Se0.5Te0.5 superconductor using ...
  • Properties of novel non-silicon materials for photovoltaic applications: A first-principle insight 
    Rasukkannu, Murugesan; Velauthapillai, Dhayalan; Bianchini, Federico; Vajeeston, Ponniah (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    Due to the low absorption coefficients of crystalline silicon-based solar cells, researchers have focused on non-silicon semiconductors with direct band gaps for the development of novel photovoltaic devices. In this study, ...
  • The average and local structure of TiVCrNbDx (x = 0, 2.2, 8) from total scattering and neutron spectroscopy 
    Nygård, Magnus Moe; Fjellvåg, Øystein; Sørby, Magnus Helgerud; Sakaki, Kouji; Ikeda, Kazutaka; Armstrong, Jeff; Vajeeston, Ponniah; Slawinski, Wojciech Andrzej; Kim, Hyunjeong; Machida, Akihiko; Nakamura, Yumiko; Hauback, Bjørn (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    The volumetric hydrogen density of 160 kg H/m 3 in TiVCrNbH 8 is among the highest for interstitial hy- drides, but the reported reversible capacity is only about 2/3 of the full theoretical capacity at room temperature. ...
  • TiO2 as a Photocatalyst for Water Splitting—An Experimental and Theoretical Review 
    Eidsvåg, Håkon; Bentouba, Said; Vajeeston, Ponniah; Shivatharsiny, Yohi; Velauthapillai, Dhayalan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Abstract: Hydrogen produced from water using photocatalysts driven by sunlight is a sustainable way to overcome the intermittency issues of solar power and provide a green alternative to fossil fuels. TiO2 has been used ...
  • Vibrational properties of High Entropy Alloy based metal hydrides probed by inelastic neutron scattering 
    Ek, Gustav; Fjellvåg, Øystein; Vajeeston, Ponniah; Armstrong, Jeff; Sahlberg, Martin; Häussermann, Ulrich (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    The vibrational properties of several High Entropy Alloy (HEA) based metal hydrides are investigated by inelastic neutron scattering (INS). HEAs have recently emerged as a new type of materials with a wide range of intriguing ...