Ca掺杂对BiFeO_(3)纳米颗粒的灵敏度和工作温度的影响

Effect of Ca doping on the sensitivity and working temperatureof BiFeO_(3) nanoparticles

BiFeO_(3)是一种在气体传感器中具有潜在应用前景的气敏材料.文中采用Ca改性BiFeO_(3)纳米颗粒构建气敏元件,且利用X射线衍射(XRD)和扫描电子显微镜(SEM)表征纳米颗粒的晶体结构和表面形貌.结果表明,Ca掺杂的BiFeO_(3)属于菱形晶体结构(R3c空间群),晶粒尺寸均匀、约为100 nm.Ca掺杂使BiFeO_(3)气敏元件的最佳工作温度从244℃降低至205℃.在最佳工作温度下,Bi_(0.95) Ca_(0.05) FeO_(3)对气体体积浓度为100×10^(-4)%的丙酮和乙醇的灵敏度为43.92和53.32,分别提高了1.65和2.70倍.文中采用气体吸附脱附和化学反应解释了Ca掺杂BiFeO_(3)的气敏机理,为优化BiFeO_(3)的气敏参数提供思路.

BiFeO_(3) is a gas sensing material with potential applications in gas sensors.In this paper,Ca modified BiFeO_(3) nanoparticles were fabricated and gas sensitive elements were constructed.The crystal structure and surface morphology were characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM).The results show that Ca doped BiFeO_(3) is of rhombohedral crystal structure(space group R3c)and has a uniform grain size(about 100 nm).Ca dopant makes the optimum operating temperature of BiFeO_(3) gas sensor reduce from 244℃to 205℃.At the optimum temperature,the sensitivities of Bi_(0.95) Ca_(0.05) FeO_(3) to acetone and ethanol(100×10^(-4)%)are 43.92 and 53.32,which are 1.65 and 2.70 times higher than those of pure BiFeO_(3),respectively.The gas sensing mechanism of BiFeO_(3) is explained by gas adsorption/desorption and chemical reaction,which provides an idea for optimizing the gas sensing parameters of BiFeO_(3) gas sensors.