High ethanol gas sensing property and modulation of magnetic and AC-conduction mechanism in 5% Mg-doped La_(0.8)Ca_(0.1)Pb_(0.1)FeO_3 compound

摘要

The effect of 5% magnesium doping on the structural, magnetic and gas sensing properties of La0.8Ca0.1Pb0.1Fe0.95Mg0.05O3 (LCPFMO) has been investigated. The nanosize compound was prepared by the Sol-Gel method, using the citric acid route. The Structural study confirms that this compound crystallizes in the orthorhombic structure with the Pbnm space group. From the magnetic measurements, we were able to show that the effect of the Mg doping is to increase the saturated magnetization and to decrease the Ferromagnetic-Paramagnetic magnetic phase transition temperature (T-C). A theoretical modulation was derived in order to confirm the domination of the ferromagnetic contribution over the Antiferromagnetic one. The AC-conductivity dependence on both temperature and frequency was studied; the study confirmed the presence of two behaviors; at high-temperature region, it was found to be only temperature dependent, while at low temperatures, it depends on both frequency and temperature parameters. At low temperature, the conduction mechanism is studied according to the NSPT model, where all parameters were discussed. The electrical Sensitivity (S) of the prepared sample to different ethanol gas concentration was investigated, using a broadband dielectric spectroscopy. It was found that 5% of magnesium insertion leads to an improvement in the sensitivity of the LCPFMO sample. This sensitivity was found to be ethanol amount dependent.