Lin Qing, Xu Jianmei, Yang Fang, Yang Xingxing, He Yun
1 College of Medical Informatics, Hainan Medical University, Haikou, China.
2 Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology, Guangxi Normal University, Guilin, China.
J Appl Biomater Funct Mater. 2018 Jan;16(1_suppl):17-25. doi: 10.1177/2280800017753948.
The nanocrystalline structure of LaCa FeO was prepared by a sol-gel method involving an auto-combustion process. The incorporation of rare-earths in LaFeO induces strain in magnetic properties, especially in terms of the following parameters: replacement amount, oxygen partial pressure, and calcination temperature.
To determine the effects of the amount of Ca ion doping agent and the calcination temperature on the microstructure, particle morphology, and magnetic properties of LaFeO crystal, we performed the following respective analytical methods: X-ray powder diffraction, Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy, and vibrating sample magnetometer tests.
The orthorhombic structure of LaFeO perovskite did not change even when it was doped with Ca ions, and its space group continued to be Pnma (No.62). FT-IR spectra confirmed that the main band appearing at 568 cm is due to the antisymmetric stretching vibration of Fe-O-Fe bonds in FeO. The introduction of Ca inhibits the growth of grains but the morphology of particles is improved. With an increasing concentration of Ca ions, magnetic behavior of the samples also witnessed an increasing trend in a proportionate manner. With an increase in calcination temperature, the enclosed area of the magnetic hysteresis curve of the sample reduced remarkably.
The growth of nanoparticles can be restrained with an increase of Ca content that is used as doping agent. The magnetic behavior of LaCa FeO tilts towards G-type antiferromagnetism; the magnetic orientation is achieved from the super exchange interaction of Fe ions with oxygen ions.
采用溶胶 - 凝胶法结合自燃烧过程制备了LaCaFeO的纳米晶结构。在LaFeO中掺入稀土会引起磁性能的应变，特别是在以下参数方面：掺杂量、氧分压和煅烧温度。
为了确定Ca离子掺杂剂的量和煅烧温度对LaFeO晶体的微观结构、颗粒形态和磁性能的影响，我们分别进行了以下分析方法：X射线粉末衍射、傅里叶变换红外（FT - IR）光谱、扫描电子显微镜和振动样品磁强计测试。
即使掺入Ca离子，LaFeO钙钛矿的正交结构也没有改变，其空间群仍然是Pnma（编号62）。FT - IR光谱证实，在568 cm处出现的主带是由于FeO中Fe - O - Fe键的反对称伸缩振动。Ca的引入抑制了晶粒生长，但改善了颗粒形态。随着Ca离子浓度的增加，样品的磁行为也呈比例增加趋势。随着煅烧温度的升高，样品磁滞回线的封闭面积显著减小。
随着用作掺杂剂的Ca含量增加，纳米颗粒的生长可以受到抑制。LaCaFeO的磁行为倾向于G型反铁磁性；磁取向是通过Fe离子与氧离子的超交换相互作用实现的。
