Dynamic Response of CoSb(2)O(6) Trirutile-Type Oxides in a CO(2) Atmosphere at Low-Temperatures

Experimental work on the synthesis of the CoSb(2)O(6) oxide and its CO(2) sensing properties is presented here. The oxide was synthesized by a microwave-assisted colloidal method in presence of ethylenediamine after calcination at 600 °C. This CoSb(2)O(6) oxide crystallized in a tetragonal structure with cell parameters a = 4.6495 and c = 9.2763 Å, and space group P4(2)/mnm. To prove its physical, chemical and sensing properties, the oxide was subjected to a series of tests: Raman spectroscopy, Scanning Electron Microscopy (SEM) and impedance (Z) measurements. Microstructures, like columns, bars and hollow hemispheres, were observed. For the CO(2) sensing test, a thick film of CoSb(2)O(6) was used, measuring the impedance variations on the presence of air/CO(2) flows (0.100 sccm/0.100 sccm) using AC (alternating current) signals in the frequency-range 0.1–100 kHz and low relative temperatures (250 and 300 °C). The CO(2) sensing results were quite good.