The point defect and electronic structure of K doped LaCo_(0.9)Fe_(0.1)O_(3)perovskite with enhanced microwave absorbing ability  

作　　者：Fan Wang Weihua Gu Jiabin Chen Yue Wu Ming Zhou Shaolong Tang Xingzhong Cao Peng Zhang Guangbin Ji 

机构地区：[1]College of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China [2]National Laboratory of Solid State Microstructures,Nanjing University,Nanjing 210093,China [3]Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Nano Research》2022年第4期3720-3728,共9页纳米研究（英文版）

基　　金：We are thankful for the financial support from the National Nature Science Foundation of China(No.51971111).

摘　　要：ABO_(3)perovskites,owning unique properties,have great research prospect in electromagnetic wave absorption field.Normally,doping can significantly regulate the dielectric loss,whereas the magnetic loss can be ignored.In this work,the crystal structure and electromagnetic properties can be regulated systematically by the K,Fe co-doping for LaCoO_(3)perovskites(LKCFO)under the condition of fixed F content.In addition,the obtained samples show the obvious interfacial polarization effect on accounting to the small size effect,which is conducive to the effective microwave absorption.By analyzing the evolution of the positron annihilation lifetime and the first-principles calculation of the oxygen density of states for the series of LKCFO perovskites,it is found that the charge transport characteristics will be controlled by the point defect generated by allelic doping.The point defect content decreases and then increases as the doping level rises.The prepared perovskite exhibits the lowest defect density and the largest dielectric loss capability,which indicates that the lower point defects promote electron migration and thus enhance the dielectric loss;thus,the electromagnetic wave absorption bandwidth up to 6.2 GHz is reached.In contrast,both insufficient and excessive K doping are detrimental to the enhancement of microwave absorption.Especially,the practical application value was investigated using Computer Simulation Technology(CST)simulations.The LKCFO-2 exhibits the smallest RCS value(below-10 dBm^(2))at almost-90°-90°with a thickness of 2 mm,providing an effective method for study excellent microwave absorption and scattering property.

关 键 词：microwave absorption perovskites DOPING effective bandwidth point defect 

分 类 号：TB3[一般工业技术—材料科学与工程]