Co-adsorption processes, kinetics and quantum mechanical modelling of nanofilm semiconductor gas sensors

2010 ◽  
Vol 207 (4) ◽  
pp. 924-929 ◽  
Author(s):  
Juan-Jesús Velasco-Vélez ◽  
Ulrich Kunze ◽  
Thomas Haas ◽  
Theodor Doll
Keyword(s):  
Gas Sensors ◽  
Co Adsorption ◽  
Quantum Mechanical ◽  
Mechanical Modelling ◽  
Adsorption Processes ◽  
Semiconductor Gas Sensors

Semiconductor gas sensors

2013 ◽  
Author(s):  
Raivo Jaaniso ◽  
Ooi Kiang Tan
Keyword(s):  
Gas Sensors ◽  
Semiconductor Gas Sensors

In situ AFM and XPS Investigation of U6+ Reduction by Fe2+ on Hematite and Pyrite

2012 ◽  
Vol 1444 ◽  
Author(s):  
Jingjie Niu ◽  
Udo Becker ◽  
Rodney Ewing
Keyword(s):  
Charge Transfer ◽  
Co Adsorption ◽  
Reduction Rate ◽  
Mulliken Charge ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Initial Ph ◽  
Adsorption Reduction ◽  
Tapping Mode Afm

ABSTRACTUranyl adsorption/reduction by Fe2+ on hematite and pyrite has been studied at neutral pH under anoxic and CO2-free conditions. XPS results confirm that more U3O8 precipitates on hematite than on pyrite reacted for 24 h in 160 μM uranyl nitrate and 160 μM Fe2+ solution at initial pH 7.3. These results are explained in terms of co-adsorption energy and U atom Mulliken charge transfer by quantum mechanical calculations. Moreover, in situ fluid tapping-mode AFM experiments on hematite indicate a deceleration of the U reduction rate within 24 h due to the passivation of the surface caused by the formation of orthorhombic U3O8 crystals. In addition, crystals observed using AFM show morphologies of orthorhombic schoepite appearing on hematite after 5 h.

Fabrication and Properties Study of the Dielectric Membranes Used as Constructive Basis for Sensitive Elements of Gas Sensors

2015 ◽  
Vol 799-800 ◽  
pp. 994-997 ◽  
Author(s):  
Denis Veselov
Keyword(s):  
Magnetron Sputtering ◽  
Qualitative Analysis ◽  
Gas Sensors ◽  
Silicon Oxide ◽  
Alkaline Solutions ◽  
Reactive Magnetron ◽  
Membrane Structures ◽  
Two Stage ◽  
Study Results ◽  
Semiconductor Gas Sensors

The article presents the properties study results of the dielectric membranes for sensitive elements of semiconductor gas sensors, obtained by different modes of the reactive magnetron sputtering of silicon with application of the two-stage unilateral anisotropic etching of silicon in the organic alkaline solutions. The qualitative analysis of the membranes stability to destructions and deformations in the course of their fabrication and heating is given. Optimum structures and modes of films formation for dielectric membrane structures are determined. The admissible thickness of the thermal silicon oxide underlay, which is does not promote to considerable membranes deformations in the course of their fabrication and heating, is identified.

Sign in / Sign up

Export Citation Format

Share Document