Ethanol Gas Sensing of Mn-Doped CoFe $_{2}$ O $_{4}$ Nanoparticles

Undoped and Mn-doped cobalt ferrite (CoFe₂O₄) nanoparticles were synthesized and characterized for thermal conductivity and magnetic properties. Room temperature ferromagnetism and an increase in saturation magnetization due to Mn doping (65.4 emu/g for 3 at.% of Mn and 20.8 emu/g for undoped CoFe₂O₄ nanoparticles) are observed. The ethanol gas sensitivity of undoped and Mn-doped (3 at.%) CoFe₂O₄ nanoparticles were experimented at ambient temperature using optical fiber based on clad-modified method. By modifying the clad exposure to gas vapor, the sensitivities were estimated to be 7 and 12 counts/100 ppm for undoped and Mn-doped CoFe₂O₄ nanoparticles, respectively, showing significant enhancement in ethanol gas sensitivity.