TY - JOUR
T1 - Size, surface structure, and doping effects on ferromagnetism in SnO 2
AU - Alanko, Gordon A.
AU - Thurber, Aaron
AU - Hanna, Charles B.
AU - Punnoose, Alex
PY - 2012/4/1
Y1 - 2012/4/1
N2 - The effects of crystallite size, surface structure, and dopants on the magnetic properties of semiconducting oxides are highly controversial. In this work, Fe:SnO 2 nanoparticles were prepared by four wet-chemical methods, with Fe concentration varying from 0 to 20. Analysis confirmed pure single-phase cassiterite with a crystallite size of 2.6 ± 0.1 nm that decreased with increasing. Fe% doped substitutionally as Fe 3+. Pure SnO 2 showed highly reproducible weak magnetization that varied significantly with synthesis method. Interestingly, doping SnO 2 with Fe < 2.5 produced enhanced magnetic moments in all syntheses; the maximum of 1.6 × 10 -4 B/Fe ion at 0.1 Fe doping was much larger than the 2.6 × 10 -6 B/Fe ion of pure Fe oxide nanoparticles synthesized under similar conditions. At Fe ≥ 2.5, the magnetic moment was significantly reduced. This work shows that (1) pure SnO 2 can produce an intrinsic ferromagnetic behavior that varies with differences in surface structure, (2) very low Fe doping results in high magnetic moments, (3) higher Fe doping reduces magnetic moment and destroys ferromagnetism, and (4) there is an interesting correlation between changes in magnetic moment, bandgap, and lattice parameters. These results support the possibility that the observed ferromagnetism in SnO 2 might be influenced by modification of the electronic structure by dopant, size, and surface structure.
AB - The effects of crystallite size, surface structure, and dopants on the magnetic properties of semiconducting oxides are highly controversial. In this work, Fe:SnO 2 nanoparticles were prepared by four wet-chemical methods, with Fe concentration varying from 0 to 20. Analysis confirmed pure single-phase cassiterite with a crystallite size of 2.6 ± 0.1 nm that decreased with increasing. Fe% doped substitutionally as Fe 3+. Pure SnO 2 showed highly reproducible weak magnetization that varied significantly with synthesis method. Interestingly, doping SnO 2 with Fe < 2.5 produced enhanced magnetic moments in all syntheses; the maximum of 1.6 × 10 -4 B/Fe ion at 0.1 Fe doping was much larger than the 2.6 × 10 -6 B/Fe ion of pure Fe oxide nanoparticles synthesized under similar conditions. At Fe ≥ 2.5, the magnetic moment was significantly reduced. This work shows that (1) pure SnO 2 can produce an intrinsic ferromagnetic behavior that varies with differences in surface structure, (2) very low Fe doping results in high magnetic moments, (3) higher Fe doping reduces magnetic moment and destroys ferromagnetism, and (4) there is an interesting correlation between changes in magnetic moment, bandgap, and lattice parameters. These results support the possibility that the observed ferromagnetism in SnO 2 might be influenced by modification of the electronic structure by dopant, size, and surface structure.
UR - http://www.scopus.com/inward/record.url?scp=84861744416&partnerID=8YFLogxK
U2 - 10.1063/1.3679455
DO - 10.1063/1.3679455
M3 - Article
AN - SCOPUS:84861744416
SN - 0021-8979
VL - 111
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 7
M1 - 07C321
ER -