Electronic structure of bridging halogen atoms in metal halide dimers studied by the AM1 method and NQR spectroscopy

✦ Synopsis

A nuclear quadrupole resonance (NQR) study of the electronic structure of bridging halogen atoms in dimers of transition and non-transition metal halides has been performed. An explanation of the differences in the NQR frequencies for transition and non-transition metal halides is proposed. The population of the bridging halogen atom orbitals and the metal-halogen bond lengths have been estimated by the AM1 method. The aim of this paper was to obtain a relationship describing the lengths of the metal-halogen bonds.

Oxygen interaction of CdS-based gas sens

Oxygen interaction of CdS-based gas sensors with different stoichiometric compositions was studied by X-ray photoelectron spectroscopy (XPS) and thermal-desorption mass spectroscopy observations combined with conductivity measurements. Three different types of film with different atomic ratios of Cd/S were used in the study of oxygen chemisorption in a low-temperature range between 300 and 570 K. Spray pyrolysis was used for the deposition of the films on glass substrates; XPS and energy dispersive spectroscopy of X-ray together with atomic force microscopy and scanning electron microscopy were used for the characterization of the composition and structure of the films. It was possible to distinguish different temperature ranges for the thermal desorption of the different adsorbed oxygen species. A comparison of the data from XPS and mass-spectroscopy observations with conductance measurements allows to conclude that metallic surface atoms are responsible for different interactions of oxygen species with CdS surfaces.

📂 Article 📅 1995 🏛 Elsevier Science 🌐 English ⚖ 379 KB