Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10713960 | Physica B: Condensed Matter | 2012 | 4 Pages |
Abstract
A study of the magnetic and structural properties of Zn1âxMxO powder (where x=0 or 0.01, and M=Mn, Fe or Co) produced by the proteic sol-gel process was undertaken. The sample crystal structure was analyzed by XRD and magnetic measurements were carried out in a SQUID magnetometer. Of the XRD analysis, all samples had hexagonal wurtzite crystal structure with P63mc space group, and no secondary phase was observed. It is observed of the M(H) measures at 2Â K, that the Co- and Mn-doped ZnO displayed saturation magnetizations (Ms) of approximately 2 and 3.2Â emu/g, respectively, and no remanence (Mr) was observed, indicating a superparamagnetic behavior in these samples. However, the Fe-doped sample showed a ferromagnetic behavior with Msâ¼0.34Â emu/g, Mrâ¼0.05Â emu/g, and coercivity (Hc)â¼1090Â Oe. Already at room temperature, the M(H) measurements reveal a purely paramagnetic behavior for Mn- and Fe-doped ZnO, indicating that the Curie temperature (Tc) is below 300Â K. However, a weak superparamagnetic behavior was observed in the Co-doped sample, indicating that Tc>300Â K.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Daniel A.A. Santos, Marcelo A. Macêdo,