论文标题
通过微波燃烧法合成的纳米结构CR取代的NI-ZN尖晶石铁氧体的结构，光学和磁性
Structural, optical and magnetic properties of nanostructured Cr-substituted Ni-Zn spinel ferrites synthesized by a microwave combustion method
论文作者
论文摘要
CR3+ - 取代的Ni-Zn铁液的纳米颗粒具有通用公式NI0.4ZN0.6-XCRXFE2O4（x = 0.0-0.6），已通过宽敞的微波燃烧途径合成。结晶相的特征是XRD，TEM，FT-I和XP的表征，揭示了尖晶石铁氧体结构而没有额外的相。通过XRD分析估计的23-32 nm的晶属尺寸在Williamson -Hall方法对晶体污渍进行校正后与TEM观察到的平均粒径相当，这表明成功合成了纳米晶体。 XRD模式的Rietveld改进分析已推断出与Vegard的实心解决方案定律序列一致的晶格参数的单调降低行为。此外，阳离子分布增加，反转因子增加表明CR3+离子的B点偏好。 XPS结果指示的氧化态和阳离子分布意味着Zn2+离子的CR3+掺杂，而Fe3+将Fe3+的部分还原为Fe2+，以在（Ni2+）0.4（Zn2+，CR3+）0.6（Fe2+，Fe2+，Fe3+）2（Fe2+，Fe3+）2（Fe2+，Fe3+）2（o2（O2-o2（O2-）中，将电荷平衡保持在（ni2+）0.4（Zn2+）中。通过光学紫外线光谱探索了光学性能，表明允许带有带隙能的直接过渡，从而用cr掺杂从3.9 eV降低到3.7 eV。此外，研究了甲基橙（MO）染料降解的光催化活性，显示在Ni0.4CR0.6Fe2O4上高达30％的Mo Dye的光二次分解6小时。室温下的振动样品磁力测定法（VSM）测量显示，Ni0.4Zn0.6Fe2O4的饱和磁化磁化强度在NI-ZN铁液中最高的Ni-Zn0.6Fe2O4，从约60至70 emu/g，CR浓度的增加到x = 0.1，而CR的浓度增加到x = 0.1，而连贯性则显示了一般范围内的CR范围。
Nanoparticles of Cr3+-substituted Ni-Zn ferrites with a general formula Ni0.4Zn0.6-xCrxFe2O4 (x = 0.0 - 0.6) have been synthesized via a facile microwave combustion route. The crystalline phase has been characterized by XRD, TEM, FT-I and XPS revealing the spinel ferrite structure without extra phases. Crystallite sizes of 23 - 32 nm as estimated by XRD analyses, after corrections for crystal stains by Williamson-Hall method, are comparable to the average particle sizes observed by TEM which indicates successfully synthesized nanocrystals. Rietveld refinement analyses of the XRD patterns have inferred a monotonic decrease behavior of the lattice parameter with Cr doping in agreement with Vegard's law of solid solution series. Furthermore, cations distribution with an increased inversion factor indicate the B-site preference of Cr3+ ions. The oxidation states and cations distribution indicated by XPS results imply the Cr3+ doping on the account of Zn2+ ions and a partial reduction of Fe3+ to Fe2+ to keep the charge balance in a composition series of (Ni2+)0.4(Zn2+, Cr3+)0.6(Fe2+, Fe3+)2(O2-)4. The optical properties were explored by optical UV-Vis spectroscopy indicating allowed direct transitions with band gap energy that decreases from 3.9 eV to 3.7 eV with Cr doping. Furthermore, the photocatalytic activity for the degradation of methyl orange (MO) dye was investigated showing largely enhanced photodecomposition up to 30% of MO dye over Ni0.4Cr0.6Fe2O4 for 6 hours. A vibrating sample magnetometry (VSM) measurements at room temperature show further enhancement in the saturation magnetization of Ni0.4Zn0.6Fe2O4 , the highest in Ni-Zn ferrites, from about 60 to 70 emu/g with the increase of Cr concentration up to x = 0.1, while the coercivity shows a general increase in the whole range of Cr doping.
