Studies on Conductance and Gas-sensing Properties of Y1-xMgxFeO3

The paper reports the preparation and the gas-sensing properties of Y1-xMgxFeO3 prepared by chemical co-precipitation method.Y2O3,Fe(NO3)3·H2O,Mg(NO3)2and HNO3· were used as starting materials.Y2O3 was dissolved in HNO3 and mixed with Fe(NO3)3 and Mg(NO3)2 solution according to intended ratio,the(NH4)2CO3 solution was dropped into the mixed solution to make Fe3+,Mg2+and Y3+ coprecipitate.The coprecipitate were washed by distilled water,filtered,dried at 100℃，milled and calcined at 900℃for 4h Mg2+ doping decreases the lattice constants and size of the material.Whenx≤0.8,the curie temperature of Y1-xMgxFeO3 is 100℃than that of YFeO3 and the conductivity of the sensor based on Y1-xMgxFeO3 is higher than that of the sensor based on YFeO3.The reason forit is that Mg2+dopingm forms many holes which can be indicated by the equation:MgWTBXY*→MgY'+h.The sensitivity to C2H5OH of the sensor based on Y1-xMgxFeO3 is higher than that of sensor based on YFeO3,but the sensitivity to other gases of the sensor based on Y1-xMgxFeO3 is almost equal to that of sensor based on YFeO3 which may be because Mg2+play a catalytic role in the reaction of C2H5OH oxidation.The sensor based on Y0.94Mg0.06FeO3 exhibits highest sensitivity to C2H5OH at 257℃，and S4.5*mol/LC2H5OH/S45*mol/Lpetrol≈4.0.It is a promising gas-sensing material.