Messanae Universitas Studiorum

Proprietà elettroniche del tiofosfato di nickel intercalato con litio

Neri, F. (1994) Proprietà elettroniche del tiofosfato di nickel intercalato con litio. Accademia Peloritana dei Pericolanti Classe FF.MM.NN., LXXII (Supplement 1). pp. 139-153.

[img] PDF - Published Version
Restricted to Registered users only

Download (4Mb)

    Abstract

    Electrical transport and Xray photoelectron spectroscopy measurements were made on lithium-intercalation complexes $Li_xNiPS_3$ Conductivity measurements werc made both during the intercalation process and after the intercalation was ceased. The intercalation process was characterized by means of the conductivity measurements ar a function of the intercalation time. Results for equilibrated samples are presented as a function of both the temperature and the lithium concentration. An overali and quick increase in the electrical conductivity, a contemporaneous decrease in the activation energy and a degenerate semiconducting behaviour at high lithium contents were observed, All these effects suggested that, with respect to the pure $NiPS_3$, a new conduction mechanism occurs at a different energy level since the very beginning of the intercalation process. In the early intercalation times a simple empirical model was formulated to correlate the data as a function of the intercalation time and those as a function of temperature. A detailed $XPS$ study was performed at the $2p$ core levels of the nickel atoms for various lithium contents. Comparison of the $Ni 2p$ peak structure, corresponding to $NiPS_3$ and $Li_xNiPS_3$ systems, shows some evident trends, In particular, a shift of the Ni main line towards lower hinding energies and a decrease in the intensity of the $Ni 2p$ satellite structures with lithium content are observed. All these findings suggest a change in the $3d$ electron configuration for high lithium concentrations. Taking the probable nickel reduction into account, a possible identification of the lithium 2s electron accepting levels was proposed.

    Item Type: Article
    Subjects: M.U.S. - Miscellanea > Atti Accademia Peloritana > Classe di Scienze Fisiche, Matematiche e Naturali > 1994 > Supplemento 1 parte 1
    M.U.S. - Miscellanea > Atti Accademia Peloritana > Classe di Scienze Medico-Biologiche > 1994 > Supplemento 1 parte 1
    M.U.S. - Miscellanea > Atti Accademia Peloritana > Classe di Scienze Giuridiche, Economiche e Politiche > 1994 > Supplemento 1 parte 1
    M.U.S. - Miscellanea > Atti Accademia Peloritana > Classe di Lettere, Filosofia e belle Arti > 1994 > Supplemento 1 parte 1
    Divisions: UNSPECIFIED
    Depositing User: Mr Nunzio Femminò
    Date Deposited: 01 Apr 2014 13:51
    Last Modified: 01 Apr 2014 13:51
    URI: http://cab.unime.it/mus/id/eprint/5134

    Actions (login required)

    View Item