Study of Sm-doped ZnO samples sintered in a nitrogen atmosphere and deposited on n-Si(1 0 0) by evaporation technique

The samarium doping zinc oxide (Zn1-xSmxO) with (x=0.0, 0.04, 0.05 and 0.17) polycrystalline thin films have been deposited on n-Si(1 0 0) substrate using thermal evaporation technique. Ceramic targets for deposition were prepared by the standard solid-state reaction method and sintered in nitrogen atmospheres. X-ray diffraction and scanning electron microscopy analyses show that the bulk and films features reveal wurtzite crystal structure with a preferential (1 0 1) crystallographic orientation and grows as hexagonal shape grains. According to the results of the Hall effect measurements, all the films show p-type conductivity, possibly a result of nitrogen incorporation into the Sm-doped ZnO samples. Magnetic measurements show that ferromagnetic behavior depends on the Sm3+ concentration. For a film with lower Sm2O3 contents (x=0.04), a phenomenon of paramagnetism has been observed. While, with further increase of Sm3+ contents (x=0.05) the ferromagnetic behavior has been observed at room temperature. However, at higher doping content of Sm3+, the ferromagnetic behavior was suppressed. The decrease of ferromagnetism with increasing doping concentration demonstrates that ferromagnetism observed at room temperature is an intrinsic property of Zn1-xSmxO films. - Highlights: → Sintering in the atmosphere of N2, reveals a highly hole concentration p-type ZnO. → The X-ray diffraction patterns confirm that dominant phases are wurtzite in all the samples. → Lattice parameters c and a show variation by increasing the substitution level of samarium (Sm). → Hysteresis loops for x=0.05 film are clearly indicating low coercivity, revealing a ferromagnetic behavior. → SEM micrographs indicate the presence of well defined hexagonal like grains.