Manganese-doped feroxyhyte nano-urchins produced by chemical methods

Mn-doped feroxyhyte (#delta#-FeOOH) nanoparticles were synthesized using a wet chemical method, starting from a mixture of iron and manganese salts. The particles obtained were needle-like, around 100 nm in length, and formed had a nano-urchin structure. The compositions of the four samples obtained were calculated to be #delta#-Fe_0.92Mn_0.08OOH, #delta#-Fe_0.75Mn_0.25OOH, #delta#-Fe_0.56Mn_0.44OOH, and #delta#-Fe_0.32Mn_0.68OOH. The superparamagnetic behavior of the nanoparticles was determined from their room-temperature Mössbauer spectra. The hyperfine magnetic field of the Mn-doped #delta#-FeOOH nanoparticles decreased when iron atoms were substituted by Mn atoms. Furthermore, Mn atoms were locally doped into #delta#-FeOOH.