  The modification and tailoring the characteristics of nanostructured
materials are of great interest due to controllable and unusual inherent
properties in such materials. A simple spray pyrolysis technique is used to
prepare pure and La-doped ZnO films. The influence of La concentration (0,
0.33, 0.45, 0.66, 0.92 and 1.04 at. %) on the structural, optical, and magnetic
properties of ZnO was investigated. The exact nominal compositions of the
prepared films were determined from the field emission scanning electron
microscope occupied with EDX. X-ray diffraction confirmed that the samples
possessed single-phase hexagonal wurtzite structure. The main crystal size was
decreased from 315.50 {\AA} to 229.04 {\AA} depending on La dopant
concentration. This decrease is due to the small ionic radius of Zn ions in
compared to La ions. The band gap values were found to be depend strongly on
La3+ ion content. Introducing La into ZnO induces a clear magnetic moment
without any distortion in the geometrical symmetry, it also reveals the
ferromagnetic coupling. The saturation magnetic moment of 1.04 at% La-doped ZnO
shows the highest value of 0.014 emu, which is ~23 times higher than pure ZnO
sample. The obtained results were discussed and compared with other literature
data and showed an acceptable agreement.
