Defect-induced magnetism in undoped and Mn-doped wide band gap zinc oxide grown by aerosol spray pyrolysis

Phase formation of hexagonal wurtzite ZnO through decomposition of Zn(OH)2 at various growth temperatures using CBD method

“…It is well known that ZnO has three stable structures, namely cubic rock-salt, zinc-blende and hexagonal wurtzite [10]. Among all metal oxide semiconductors ZnO is important both scientifically and industrially due to its wide band gap of 3.37 eV, and large exciton binding energy of 60 meV at room temperature (RT) [11,12].…”

A study on the sensing of NO2 and O2 utilizing ZnO films grown by aerosol spray pyrolysis

“…12, two absorption peaks associated with paramagnetic (PM) and ferromagnetic (FMR) resonant fields were observed at approximately 150 mT and 300 mT, respectively. The observed PM feature could be due to the different magnetic clusters of defects situated near the surface [57]. It is clear from the spectra that a FM signal is observed for the film grown for 20 min.…”

“…A sharper peak was also observed at 300 mT(a) and (b) indicating that the PM is dominant in this film. The decrease in FM ordering with an increase in deposition time is due to the larger crystallite sizes [57,58]. In addition, the hyperfine coupling structures, which are most likely from Zn 2þ nucleus electron interaction, vanish with increasing deposition time.…”

Characteristics of the mechanical milling on the room temperature ferromagnetism and sensing properties of TiO2 nanoparticles

“…The observed RTFM is thought to be due to higher V O on the TiO 2 NPs surface (see PL results) and structure defect induced by milling process which result in coalescence of ferromagnetic domains [43] such as reduced crystallites size (see Table 1). Previous studies [9,[44][45][46] showed that larger crystals are detrimental to magnetic properties. Moreover, the origin of ferromagnetism for TiO 2 NPs diluted magnetic semiconductors can be explained by various carrier mediated mechanisms that include double-exchange, super-exchange or Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange interactions [43].…”