Amghar Mohamed, Bougoffa Amira, Trabelsi Abdessalem, Oueslati Abderrazek, Dhahri Essebti
Laboratory of Applied Physics, Faculty of Sciences of Sfax, University of Sfax B. P. 1171 Sfax 3000 Tunisia
Laboratory of Spectroscopic Characterization and Optic Materials, University of Sfax, Faculty of Sciences of Sfax B. P. 1171 3000 Sfax Tunisia.
RSC Adv. 2022 May 26;12(25):15848-15860. doi: 10.1039/d2ra01800d. eCollection 2022 May 23.
In this paper, nanoparticles of ( = 0.05 and = 0.1) were synthesized by the sol-gel auto-combustion method and characterized by various techniques. X-ray diffraction (XRD) for structural characterization confirms the successful formation of a cubic spinel structure with the space group 3̄. Their morphology was evaluated with a scanning electron microscope (SEM) which shows an agglomeration of nanoparticles. To characterize the electrical behavior of our compounds, we used impedance spectroscopy at temperatures ranging from 313 K to 653 K and frequencies ranging from 0.1 Hz to 1 MHz. The experimental data for the real and imaginary impedance parts were mounted on the equivalent grain resistance ( )//fractal capacitance (CPE) circuit. Indeed, the activation energies extracted from the electrical conductivity and the resistance of the grain resistance ( ) closed and confirmed a transformation of the electrical behavior confirmed by a decrease in the resistance of the materials. The study of the alternating conductivity shows a Jonscher curve behavior and a thermally activated conduction process. The variation of the exponent "" as a function of temperature shows, on the one hand, the presence of two models of conduction correlated barrier jump (CBH) and non-overlapping small polaron tunneling (NSPT) for = 0.05 and, on the other hand, a CBH model for = 0.1.
在本文中,通过溶胶 - 凝胶自燃法合成了( = 0.05和 = 0.1)的纳米颗粒,并采用各种技术对其进行了表征。用于结构表征的X射线衍射(XRD)证实成功形成了具有空间群3̄的立方尖晶石结构。用扫描电子显微镜(SEM)评估了它们的形态,结果显示纳米颗粒发生了团聚。为了表征我们化合物的电学行为,我们在313 K至653 K的温度范围和0.1 Hz至1 MHz的频率范围内使用了阻抗谱。将实部和虚部阻抗的实验数据拟合到等效晶粒电阻( )//分形电容(CPE)电路上。实际上,从电导率和晶粒电阻( )的电阻中提取的活化能相近,并证实了材料电阻降低所确认的电学行为转变。交流电导率的研究显示出琼谢尔曲线行为和热激活传导过程。指数“ ”随温度的变化表明,一方面,对于 = 0.05存在两种传导模型,即相关势垒跳跃(CBH)和非重叠小极化子隧穿(NSPT),另一方面,对于 = 0.1存在CBH模型。