Laser desorption time-of-flight mass spectrometry of atomic switch memory Ge2Sb2Te5 bulk materials and its thin films.

Rationale: Although the structure of atomic switch Ge2Sb2Te5 (GST) thin films is well established, the composition of the clusters formed in the plasma plume during pulsed-laser deposition (PLD) is not known. Laser Desorption Ionization Time-of-Flight Mass Spectrometry (LDI-TOF MS) is an effective method for the generation and study of clusters formed by laser ablation of various solids and thus for determining their structural fragments.

Methods: LDI of bulk or PLD-deposited GST thin layers and of various precursors (Ge, Sb, Te, and Ge-Te or Sb-Te mixtures) using a nitrogen laser (337 nm) was applied while the mass spectra were recorded in positive and negative ion modes using a TOF mass spectrometer equipped with a reflectron while the stoichiometry of the clusters formed was determined via isotopic envelope analysis.

Laser ablation of AgSbS(2) and cluster analysis by time-of-flight mass spectrometry.

Thin films of AgSbS(2) are important for phase-change memory applications. This solid is deposited by various techniques, such as metal organic chemical vapour deposition or laser ablation deposition, and the structure of AgSbS(2)(s), as either amorphous or crystalline, is already well characterized. The pulsed laser ablation deposition (PLD) of solid AgSbS(2) is also used as a manufacturing process.

In-situ measurement of reversible photodarkening in ion-conducting chalcohalide glass.

We report the kinetics of below band-gap light induced photodarkening in (80-x)GeS(2)-20Ga(2)S(3)-xAgI (x = 0 and 20 mol %) bulk chalcogenide glasses by measuring the time evolution of transmission spectra at every 10 milliseconds. The results prove clearly the enhancement of photosensivity upon doping of AgI compound in glasses. It is interesting to find that PD observed in AgI-doped glass totally disappears two hours later after the laser exposing even at room temperature.

Chalcogenide coatings of Ge15Sb20S65 and Te20As30Se50.

Chalcogenide coatings are investigated to obtain either optical components for spectral applications or optochemical sensors in the mid-infrared. The deposition of Ge(15)Sb(20)S(65) and Te(20)As(30)Se(50) chalcogenide glasses is performed by two physical techniques: electron-beam and pulsed-laser deposition. The quality of the film is analyzed by scanning electron microscopy, atomic force microscopy, and energy dispersive spectroscopy to characterize the morphology, topography, and chemical composition.