Sangeetha R, Muthukumaran S, Ashokkumar M
PG and Research Department of Physics, Government Arts College, Melur 625 106, Madurai, Tamilnadu, India.
PG and Research Department of Physics, Government Arts College, Melur 625 106, Madurai, Tamilnadu, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2015 Jun 5;144:1-7. doi: 10.1016/j.saa.2015.02.056. Epub 2015 Feb 21.
Zn(0.96-x)Cu0.04Mn(x)O (0⩽x⩽0.04) nanoparticles were synthesized by sol-gel method. The X-ray diffraction pattern indicated that doping of Mn and Cu did not change the ZnO hexagonal wurtzite structure. The Mn doped nanoparticles had smaller average crystallite size than un-doped Zn0.96Cu0.04O nanoparticles due to the distortion in the host ZnO lattice. This distortion prevented the subsequent growth and hence the size reduced by Mn doping. The changes in lattice parameters, average crystallite size, peak position and peak intensity confirmed the Mn substitution in Zn-Cu-O lattice. The Mn and Cu co-doping increased the charge carrier density in ZnO nanoparticles which led to increase the dielectric constant. The dielectric constant also varied by depend the size of the nanoparticles. The change in morphology by Mn-doping was studied by transmission electron microscope. The optical absorption and band gap were changed with respect to both compositional and size effects. The band gap was initially increased from 3.65 to 3.73 eV at 1% of Mn doping, while decreasing trend in band gap was noticed for further increase of Mn. The band gap was decreased from 3.73 to 3.48 eV when Mn concentration was increased from 2% to 4%. Presence of chemical bonding and purity of the nanoparticles were confirmed by FTIR spectra. The antibacterial study revealed that that the antibacterial activity of Zn0.96Cu0.04O is enhanced by Mn doping.
采用溶胶-凝胶法合成了Zn(0.96-x)Cu0.04Mn(x)O（0⩽x⩽0.04）纳米颗粒。X射线衍射图谱表明，Mn和Cu的掺杂并未改变ZnO的六方纤锌矿结构。由于主体ZnO晶格中的畸变，Mn掺杂的纳米颗粒的平均晶粒尺寸比未掺杂的Zn0.96Cu0.04O纳米颗粒更小。这种畸变阻碍了后续的生长，因此通过Mn掺杂尺寸减小。晶格参数、平均晶粒尺寸、峰位置和峰强度的变化证实了Mn在Zn-Cu-O晶格中的取代。Mn和Cu的共掺杂增加了ZnO纳米颗粒中的电荷载流子密度，从而导致介电常数增加。介电常数也因纳米颗粒的尺寸而异。通过透射电子显微镜研究了Mn掺杂引起的形貌变化。光吸收和带隙随成分和尺寸效应而变化。在1%的Mn掺杂时，带隙最初从3.65 eV增加到3.73 eV，而随着Mn的进一步增加，带隙出现下降趋势。当Mn浓度从2%增加到4%时，带隙从3.73 eV降低到3.48 eV。FTIR光谱证实了纳米颗粒中化学键的存在和纯度。抗菌研究表明，Mn掺杂增强了Zn0.96Cu0.04O的抗菌活性。
