The acetone-sensing properties of the undoped and Pd doped perovskite-type oxides NdFeO3 were investigated from room temperature to 400°C. The perovskite-type NdFeO3 was synthesized by a sol-gel method, and the dopants Pd with the content from 1wt% to 5wt% were implanted into NdFeO3 nanoparticles by thermal diffusion. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques show that NdFeO3 is an orthorhombic structure with the average particle size of about 40 nm. A giant acetone-sensing response of 675.7 is observed when the Pd content in NdFeO3 powders is about 3wt%. The response and recovery time of the sensor to the 5×10–4 acetone gas are 16 and 1 s, respectively. At the same time, it performs a good selectivity to acetone gas and may be a new promising material candidate for the acetone-sensor development.
Zhan-lei WuRu ZhangMa ZhaoShao-ming FangZhou-xiang HanJi-fan HuKai-ying Wang
NdFe1–xCoxO3 (x=0.0–0.5) powders were prepared by a sol-gel citric method. X-ray diffraction was used to confirm the phase composition of the powders. All the samples are orthorhombic structure. The unit cell volume and grain size decreased with an increase of Co content x. The conduction type of the NdFe1–xCoxO3 perovskite oxides changed with the increasing Co content x. When x<0.3, the oxides showed p-type conduction behavior, and then changed to n-type when x>0.3. All the sensors presented higher r...