Crystallography, Impurities and Magnetic Properties of Mn-Doped ZnO Nanoparticles Prepared by Coprecipitation Method

Abstract

Introduction of Mn2+ions into ZnO in the form of Zn(1-x)MnxO (0.00≤x≤0.25) has been done by means of coprecipitation method at low temperature using Zn(CH3COO)2·2H2O, Mn(CH3COO)2·4H2O, HCl, and NH4OH as starting materials. The XRD analysis showed that the produced Zn(1-x)MnxO (0.00≤x≤0.09) samples were crystallized in single phase of wurtzite with hexagonal structures. Besides the wurtzite, the presence of the secondary phase of hetaerolite ZnMn2O4with tetragonal structures was detected in the samples having 0.10≤x≤0.25. The nanometer-sized Zn(1-x)MnxO crystals obtained from XRD analysis were well confirmed by SEM and TEM images. The electron diffraction data showed that the secondary phase formed even for 0.01 and 0.10 Mn-doping samples were ZnMn2O4and MnO2. The VSM data indicate that the paramagnetic properties of Mn doping occurred at 0.00≤x≤0.06 and 0.10≤x≤0.25 as well as superparamagnetic properties occur in Mn doping 0.07≤x≤0.09. The most interesting fact in this study was the formation of secondary phases in all Mn-doped ZnO samples, even for the smallest x of 0.01.

Coupling between γ-irradiation and synchrotron-radiation-based XAFS techniques for studying Mn-doped ZnO nanoparticles

“…Meanwhile, the increase of Mn content may lead to Mn clusters in the ZnO matrix. Many authors (Harsono et al, 2017;Luo et al, 2014;Subramanian et al, 2011;Hao et al, 2012) have also reported the same trend for our samples.…”

“…As mentioned above, due to the unique optoelectronic performance of ZnO nanostructures, they have wide application in LEDs, lasers, solar cells and optical/ radiation sensors (O ¨zgu ¨r et al, 2005;Schmidt-Mende & MacManus-Driscoll, 2007). Many researchers in nanotechnology have used a variety of methods to synthesize zinc oxide NPs doped with mono-doping or co-doping transition metal ions (Mn, Fe, Co, Ni, Cr); for example, sol-gel (Khorsand Zak et al, 2012;Liu et al, 2010), spray (Shinde et al, 2006), radio-frequency magnetron sputtering (Ashida et al, 2006), pulsed laser deposition (Tiwari et al, 2002), metal organic deposition (Tuan et al, 2004) and co-precipitation (Harsono et al, 2017;Tan et al, 2014;Bagheri et al, 2013). Also, -ray irradiation has been used for the preparation of metal oxides (Imam et al, 2021a).…”

Effects of Mn Substitution on Magnetic Properties of ZnO Nanoparticles

“…The series of Zn(1-x)MnxO (MZO) nanoparticles were prepared by the coprecipitation method as reported in [16]. Here, we focus on MZO with x= 0.03 (MZO3), 0.05 (MZO5) and 0.07 (MZO7) as a crossover of paramagnetic to superparamagnetic-like state has been suggested to occurs at this concentration range [16].…”

“…Therefore, one can expect the increase in the magnetic moment of MZO by increasing the concentration of either Mn or charge carriers via the introduction of oxygen vacancy. The magnetism of MZO has been intensively studied [9,[11][12][13][14][15][16][17]. It was reported that MZO thin films have ferromagnetic feature at room temperature [12,13], while polycrystalline MZO exhibits paramagnetic behavior even at 15% of Mn-concentration [11,16].…”

“…The magnetism of MZO has been intensively studied [9,[11][12][13][14][15][16][17]. It was reported that MZO thin films have ferromagnetic feature at room temperature [12,13], while polycrystalline MZO exhibits paramagnetic behavior even at 15% of Mn-concentration [11,16]. Mukherjee et al [13] stated that effective carrier densities are the key in the magnetism of MZO thin films.…”