Impact of cadmium doping in Ni-Co ferrites on its magnetic properties and gas sensing behavior

Abstract

The Ni sub(0.5-x)Cd sub(x)Co sub(0.5)Fe sub(2)O sub(4) (x=0.0-0.5) ferrites series was synthesized by the combustion technique using succinic acid as a fuel. The ferrites were characterized by XRD, ICP-AES, FTIR, Raman, XPS, HRTEM, and BET surface area analyzer. The characterization results confirmed the formation of nanosized spinel ferrites and demonstrated that Cd substitution alters the structural, morphological, and surface properties of the ferrites. The magnetic characterization highlighted a distinct variation in magnetic behavior upon the substitution of nickel with cadmium, reflecting the impact of cation redistribution within the spinel lattice. Thick-film sensors fabricated from these ferrites on glass substrates were investigated for Cl sub(2) gas sensing among other gases. Among all ferrite compositions, the x=0.2 and x=0.3 exhibited superior sensing performance at room temperature and 100 degrees C, showing high sensitivity of 74-90 percent over a 50-300 ppm Cl sub(2) concentration range, along with ultrafast response and recovery times of less than 3 s and 4 s, respectively. The excellent selectivity, reproducibility, and rapid sensing behavior establish these ferrites as promising materials for chlorine gas sensor applications.