Electrical and dielectric properties of Ni_(0.5)Co_(0.5)Ga_(x)Fe_(1.8-x)O_(4)(x≤1.0)spinel ferrite microspheres  

作　　者：S.Akhtar M.A.Almessiere B.Unal A.Demir Korkmaz Y.Slimani N.Tashkandi A.Baykal A.Ul-Hamid A.Manikandan 

机构地区：[1]Department of Biophysics,Institute for Research and Medical Consultations(IRMC),Imam Abdulrahman Bin Faisal University,P.O.Box 1982,Dammam,31441,Saudi Arabia [2]Department of Physics,College of Science,Imam Abdulrahman Bin Faisal University,P.O.Box 1982,Dammam,31441,Saudi Arabia [3]Institute of Forensic Sciences and Legal Medicine,Istanbul University-Cerrahpasa,Buyukcekmece Campus,Buyukcekmece-Istanbul,34500,Turkey [4]Department of Chemistry,Istanbul Medeniyet University,Uskudar/Istanbul,34700,Turkey [5]Department of Nanomedicine Research,Institute for Research and Medical Consultations(IRMC),Imam Abdulrahman Bin Faisal University,P.O.Box 1982,Dammam,31441,Saudi Arabia [6]Core Research Facilities,King Fahd University of Petroleum&Minerals,Dhahran,13261,Saudi Arabia [7]Department of Chemistry,Bharath Institute of Higher Education and Research(BIHER),Bharath University,Chennai,Tamil Nadu,600073,India [8]Center for Catalysis and Renewable Energy,Bharath Institute of Higher Education and Research(BIHER),Chennai,Tamil Nadu,600073,India

出　　处：《Journal of Rare Earths》2023年第2期259-267,共9页稀土学报（英文版）

摘　　要：Microspheres of Ni_(0.5)Co_(0.5)Ga_(x)Fe_(2-x)O_(4)(x≤1.0)microsphere spinel ferrites(NiCoGaFe-MSFs)and carbon spheres were prepared via a hydrothermal technique.The micro structure of microspheres was investigated through scanning and transmission electron microscopy(SEM and TEM),respectively,and X-ray diffraction(XRD).The electrical and dielectric properties of NiCoGaFe-MSF at temperatures ranging from20 to 120℃(between 293,1×10^(3)and 393.1×10^(3))for f≤3.0 MHz were systematically studied as a result of 3D graphical drawing of the data obtained from an impedance analyzer.Relevant parameters such as ac/dc conductivity,dielectric loss,dielectric constant,activation energy,dissipation factor and Cole-Cole impedance spectra were extensively evaluated for various Ga ion mole ratios in the substitution where x≤1.0.We notice that the ac conductivity mostly obeys exponential power law rules,which vary significantly with the substitution ratios of Ga ions.Impedance analyses confirm that differences in conduction mechanisms in NiCoGaFe-MSFs are mainly due to grain-to-grain boundaries related to Ga ion substitution ratios.The change in dielectric constant of NiCoGaFe-MSFs is strongly dependent on the substitution rates and results in a normal dielectric distribution with frequency.The tangential loss for all micro spheres is observed to vary with measured temperatures and their frequency dependencies can be attributed to the conduction mechanism similar to Koop’s phenomenological model.It is clearly seen that the formation of semicircles is dominated by all the NiCoGaFe-MSFs and the diameter of the semicircles mostly decreases with increasing temperature,as evidence of a temperaturedependent relaxation mechanism.

关 键 词：Spinel ferrites MICROSPHERES Electrical properties Ac/dc conductivity Dielectric properties Rare earths 

分 类 号：TG146.45[一般工业技术—材料科学与工程]