The formaldehyde sensitivity of LaFe1-xZnxO3-based gas sensor

Rare earth oxides LaFe1-x Zn (x) O-3 were synthesized by sol-gel method. The X-ray diffraction patterns (XRD) showed that LaFe1-x Zn (x) O(3)oxides are single phase with orthorhombic perovskite structure, they all show p-type semiconducting properties. Among nanocrystalline LaFe1-x Zn (x) O-3 oxides, LaFe0.77Zn0.23O3 exhibits the highest sensitivity of 44.5 to 100 ppm formaldehyde. The optimal working temperature was found to be around 240 degrees C. Moreover the LaFe0.77Zn0.23O3 exhibites short response and recovery time to 100 ppm formaldehyde. The lattice parameter doesn't agree with Vegard's law with the increasing Zn content, and the relative density was 70-80%.