Kadyrzhanov Kayrat K, Egizbek Kamila, Kozlovskiy Artem L, Zdorovets Maxim V
Engineering Profile Laboratory, L.N. Gumilyov Eurasian National University, Astana 010008, Kazakhstan.
Laboratory of Solid State Physics, The Institute of Nuclear Physics, Almaty 050032, Kazakhstan.
Nanomaterials (Basel). 2019 Jul 27;9(8):1079. doi: 10.3390/nano9081079.
The work is dedicated to the study of the structural and optical characteristics, as well as the phase transformations, of ferrite nanoparticles of CeO-FeO. To characterize the results obtained, the methods of scanning and transmission microscopy, X-ray diffraction (XRD) spectroscopy, and Mössbauer spectroscopy were applied. It was found that the initial nanoparticles are polycrystalline structures based on cerium oxide with the presence of X-ray amorphous inclusions in the structure, which are characteristic of iron oxide. The study determined the dynamics of phase and structural transformations, as well as the appearance of a magnetic texture depending on the annealing temperature. According to the Mossbauer spectroscopy data, it has been established that a rise in the annealing temperature gives rise to an ordering of the magnetic properties and a decrease in the concentration of cationic and vacancy defects in the structure. During the life test of synthesized nanoparticles as cathode materials for lithium-ion batteries, the dependences of the cathode lifetime on the phase composition of nanoparticles were established. It is established that the appearance of a magnetic component in the structure result in a growth in the resource lifetime and the number of operating cycles. The results show the prospects of using these nanoparticles as the basis for lithium-ion batteries, and the simplicity of synthesis and the ability to control phase transformations opens up the possibility of scalable production of these nanoparticles for cathode materials.
这项工作致力于研究CeO-FeO铁氧体纳米颗粒的结构和光学特性以及相变。为了表征所获得的结果，应用了扫描和透射显微镜、X射线衍射（XRD）光谱和穆斯堡尔光谱方法。发现初始纳米颗粒是基于氧化铈的多晶结构，结构中存在X射线非晶夹杂物，这是氧化铁的特征。该研究确定了相和结构转变的动力学，以及取决于退火温度的磁织构的出现。根据穆斯堡尔光谱数据，已确定退火温度的升高会导致磁性能的有序化以及结构中阳离子和空位缺陷浓度的降低。在将合成的纳米颗粒作为锂离子电池阴极材料的寿命测试中，确定了阴极寿命与纳米颗粒相组成的关系。已确定结构中磁性成分的出现会导致资源寿命和操作循环次数的增加。结果表明了使用这些纳米颗粒作为锂离子电池基础的前景，并且合成的简单性和控制相变的能力为大规模生产这些用于阴极材料的纳米颗粒开辟了可能性。
