Triyono Djoko, Yunida Y, Rafsanjani Rifqi Almusawi
Department of Physics, Faculty of Mathematics and Natural Science (FMIPA), Universitas Indonesia Depok, Depok 16424, Indonesia.
Materials (Basel). 2021 Dec 7;14(24):7501. doi: 10.3390/ma14247501.
In this study, the effect of heat treatment on the structural, magnetic and electrical properties of LaFeMnO prepared via the sol-gel and sintering method were investigated. The heat-treatment conditions, i.e., the calcination temperature (1023 K and 1173 K), sintering temperature and time (1273 K for 1 and 3 h) were carried out. X-ray diffraction (XRD) revealed orthorhombic (62) symmetry without any impurity phase for all samples. X-ray photoelectron spectroscopy confirmed the presence of Fe-Fe-Fe and Mn-Mn mixed states, and lanthanum and oxygen vacancies resulting in various magnetic exchange interactions. Furthermore, the magnetisation hysteresis showed enhanced hysteresis loops accompanied by an increase in magnetisation parameters with calcination temperature. The Raman phonon parameters induced a redshift in the phonon modes, alongside an increase in the intensity and compression of the linewidth, reflecting a decrease in lattice distortion, which was confirmed by XRD. The temperature-dependent conductivity showed that the conduction mechanism is dominated by p-type polaron hopping, and the lowest activation energy was approximately 0.237 ± 0.003 eV for the minimum heat-treatment conditions. These results show that varying heat-treatment conditions can significantly affect the structural, magnetic and electrical properties of the LaFeMnO system.
在本研究中，研究了热处理对通过溶胶-凝胶和烧结法制备的LaFeMnO的结构、磁性和电学性能的影响。进行了热处理条件，即煅烧温度（1023 K和1173 K）、烧结温度和时间（1273 K，1小时和3小时）。X射线衍射（XRD）表明，所有样品均为正交（62）对称性，无任何杂质相。X射线光电子能谱证实了Fe-Fe-Fe和Mn-Mn混合态的存在，以及镧和氧空位导致的各种磁交换相互作用。此外，磁化滞后显示出增强的磁滞回线，并且随着煅烧温度的升高，磁化参数增加。拉曼声子参数导致声子模式发生红移，同时线宽的强度和压缩增加，这反映了晶格畸变的减小，XRD证实了这一点。温度依赖性电导率表明，传导机制以p型极化子跳跃为主，在最低热处理条件下，最低活化能约为0.237±0.003 eV。这些结果表明，改变热处理条件会显著影响LaFeMnO体系的结构、磁性和电学性能。
