title: Structural elucidation of AgAsS2 glass by the analysis of clusters formed during laser desorption ionisation applying quadrupole ion trap time-of-flight mass spectrometry.
abstract: BACKGROUND
  The structure of AgA(s)S2 glass, which has a broad range of applications, is still not well understood and a systematic mass spectrometric analysis of AgA(s)S2 glass is currently not available. Elucidation of the structure should help in the development of this material.
  
  
  METHODS
  The AgA(s)S2 glass was prepared by the melt-quenched technique. Laser desorption ionisation (LDI) using quadrupole ion trap time-of-flight mass spectrometry (QIT-TOFMS) was used to follow the generation of Ag(m)As(n)S(x) clusters. The stoichiometry of the clusters generated was determined via collision-induced dissociation (CID) and modelling of isotopic patterns. The AgA(s)S2 glass was characterised by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy.
  
  
  RESULTS
  The LDI of AgA(s)S2 glass leads to the formation of unary (Ag+/− and As(3+)) species, 38 binary (As(n)S(x), Ag(m)S(x)), and 98 ternary (Ag(m)As(n)S(x)) singly charged clusters. The formation of silver-rich nano-grains during AgA(s)S2 glass synthesis has been identified using TEM analysis and also verified by QIT-TOFMS.
  
  
  CONCLUSIONS
  TOFMS was shown to be a useful technique to study the generation of Ag(m)As(n)S(x )clusters. SEM, TEM and EDX analysis proved that the structure of AgA(s)S2 glass is ‘grain-like’ where grains are either: (1) Silver-rich ‘islands’ (Ag(m,) m up to 39) connected by arsenic and/or sulfur or arsenic sulfide chains or (2) silver sulfide (Ag2S)m (m = 9-20) clusters also similarly inter-connected. This obtained structural information may be useful for the development of ultra-high-density phase-change storage and memory devices using this kind of glass as a base.
authors: Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5/A14, 625 00, Brno, Czech Republic.
authors: Ravi Madhukar
authors: RM
authors: Mawale
authors: Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5/A14, 625 00, Brno, Czech Republic.|Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic.
authors: Milan
authors: M
authors: Alberti
authors: Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 95, Pardubice, 53210, Czech Republic.
authors: Bo
authors: B
authors: Zhang
authors: Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 95, Pardubice, 53210, Czech Republic.
authors: Max
authors: M
authors: Fraenkl
authors: Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 95, Pardubice, 53210, Czech Republic.
authors: Tomas
authors: T
authors: Wagner
authors: Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5/A14, 625 00, Brno, Czech Republic.|Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic.|CEPLANT, R&D Centre for low-cost plasma and nanotechnology surface modifications, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic.
authors: Josef
authors: J
authors: Havel