Fe doped hydroxyapatite thick films modified via swift heavy ion irradiation for CO and CO2 gas sensing application

Swift Heavy Ion irradiation (SHI) technique is utilized to modify the structure and surface morphology of Fe doped Hydroxyapatite (Fe-HAp) thick films for CO and CO2 gas sensing applications. Nano-crystalline HAp is synthesized by wet chemical precipitation route and ion exchange process is employed to replace of Ca ion with Fe ions. Thick film Fe-HAp sensors, having variable Fe doping concentrations, are prepared by using screen printing technique. The Fe-HAp thick films are irradiated using Ag7+ ion (100 MeV) with variable ion fluences ranging from 3 x 10(10) to 3 x 10(13) ions/cm(2) for modifying the sensor surface. Structural and morphological changes with respect to ion fluence are observed by means of XRD, SEM and AFM analysis. The parameters such as operating temperature, response/recovery time, and uptake capacity for pristine and modified Fe-HAp sensors are experimentally determined. The investigations reveal that the SHI irradiated Fe-HAp film (3 x 10(11) ions/cm(2)) shows improved gas sensing characteristics at relatively lower operating temperature in comparison to pristine film. It is concluded that Fe-HAp film can be a potential candidate for developing low cost, energy saver and high performance CO and CO2 sensor. (C) 2013 Elsevier B.V. All rights reserved.