[摘要]：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.
