Kanwal Sidra, Khan Muhammad Tahir, Mehboob Nasir, Amami Mongi, Zaman Abid
Department of Physics, Riphah International University, 44000 Islamabad, Pakistan.
Department of Chemistry College of Sciences, King Khalid University, P.O. Box 9004, 61421 Abha, Saudi Arabia.
ACS Omega. 2022 Aug 31;7(36):32184-32193. doi: 10.1021/acsomega.2c03375. eCollection 2022 Sep 13.
In current work, pure ZnO and Zn CuCo O (0 ≤ ≤ 0.05) nanoparticles were synthesized by the co-precipitation method. Structural analysis and phase determination of the formed nanoparticles was carried out using X-ray diffraction (XRD) and Williamson-Hall plots. The hexagonal wurtzite structure was manifested by all the samples with divergent microstructures. The change in lattice parameters, bond length, dislocation density, and lattice strain indicates that Cu and Co were successfully incorporated. Average crystallite size was found to be in the range of 32.16-45.42 nm for various doping concentrations. Field emission scanning electron microscopy results exhibited that the surface morphology is an amalgam of spherical-like and hexagon-like structures. Spherical-shaped grains were homogeneous and evenly distributed all over the structure. Fourier transform infrared spectra indicated that the absorption bands were blue-shifted with increasing Co concentration. The UV-visible absorption spectra showed high absorption in the UV region and weak absorption in the visible region. An increase in the energy band gap for the maximum absorption peak was observed from 3.49 eV for ZnO to 3.88 eV for ZnCuCoO. The Burstein-Moss effect explained the noticed blue shift in absorption spectra and energy band gaps. The vibrating sample magnetometer study revealed the change in the diamagnetic behavior of pure ZnO to the ferromagnetic behavior of the prepared nanoparticles at room temperature for different doping concentrations. In the current study, we have developed the room-temperature ferromagnetism (RTFM) for Cu and Co co-doped ZnO nanoparticles. Since RTFM is the key objective for dilute magnetic semiconductors, therefore it can be served as the desirable expectant for spintronics applications with improved functionalities and device concepts.
在当前工作中，采用共沉淀法合成了纯ZnO和ZnCuCoO（0≤≤0.05）纳米颗粒。使用X射线衍射（XRD）和威廉姆森-霍尔图对形成的纳米颗粒进行了结构分析和相测定。所有样品均呈现出六方纤锌矿结构，且微观结构各异。晶格参数、键长、位错密度和晶格应变的变化表明Cu和Co已成功掺入。对于不同的掺杂浓度，平均晶粒尺寸在32.16 - 45.42 nm范围内。场发射扫描电子显微镜结果显示，表面形态是球形和六边形结构的混合体。球形晶粒均匀且遍布整个结构。傅里叶变换红外光谱表明，吸收带随着Co浓度的增加发生蓝移。紫外可见吸收光谱显示在紫外区域有高吸收，在可见光区域有弱吸收。观察到最大吸收峰的能带隙从ZnO的3.49 eV增加到ZnCuCoO的3.88 eV。伯斯坦-莫斯效应解释了吸收光谱和能带隙中观察到的蓝移现象。振动样品磁强计研究表明，对于不同的掺杂浓度，在室温下纯ZnO的抗磁性行为转变为所制备纳米颗粒的铁磁性行为。在当前研究中，我们开发了用于Cu和Co共掺杂ZnO纳米颗粒的室温铁磁性（RTFM）。由于RTFM是稀磁半导体的关键目标，因此它可作为具有改进功能和器件概念的自旋电子学应用的理想期望。
