Colossal dielectric response and complex impedance analysis of LaFeO_(3)ceramics  

作　　者：Sushrisangita Sahoo K.P.Andryushin P.K.Mahapatra R.N.P.Choudhary 

机构地区：[1]Research Institute of Physics,Southern Federal University 344090,Rostov-on-Don,Russia [2]Department of Physics,Siksha O Anusandhan(Deemed to be University)Bhubaneswar,India

出　　处：《Journal of Advanced Dielectrics》2022年第5期60-66,共7页先进电介质学报（英文）

基　　金：supported by the Ministry of Science and Higher Education of the Russian Federation State task in the field of scientific activity,scientific project No.(0852-2020-0032)/(BAZ0110/20-3-07IF)。

摘　　要：The present investigations mainly focused on the colossal dielectric response and complex impedance analysis of LaFeO3 ceramics.The studied sample was prepared by a citrate gel method.Structural and microstructural properties are analyzed from the XRD pattern and SEM micrograph.The anomalies in the dielectric constant versus temperature plots are analyzed on the basis of polarization induced by the Maxwell-Wagner mechanisms and ferromagnetic interaction between the Fe3+ions driven by the oxygen vacancy mediated Fe^(3+)-Vo-Fe3+exchange interaction A giant dielectric permittivity in the order of~105 was observed in the sample even at the room temperature for 100 Hz.The colossal dielectric constant in LaFeO3 is mainly driven by the internal barrier layer capacitor(IBLC)formation.The formation of IBLC was explained on the basis of highly insulating grain boundary and less resistive/semiconducting grain,which was confirmed from both the resistance and capacitance of grain and grain boundary from the impedance analysis.The non-Debye-type relaxation process associated with the grain and grain boundary effect was investigated from the broad and asymmetric relaxation peak.The relaxation time for both the grain and grain boundary effect was also calculated.In addition to this,we have also analyzed the normalized bode plot of imaginary part of impedance and electrical modulus which suggests the relaxation process dominated by the short-range movement of charge carriers.

关 键 词：FERRITE giant dielectric constant non-Debye relaxation. 

分 类 号：TM28[一般工业技术—材料科学与工程]