Effect of Eu-Er substitution on structural,optical,dielectric,and electrical properties of Ba_(0.5)Sr_(0.5)Eu_(x)Er_(x)Fe_(12-2x)O_(19) hexaferrite  

作　　者：Jayashri Mahapatro Sher Singh Meena Sadhana Agrawal 

机构地区：[1]Department of Physics,National Institute of Technology Raipur,Raipur,492010,India [2]Solid State Physics Division,Bhabha Atomic Research Centre,Mumbai,400085,MS,India

出　　处：《Journal of Rare Earths》2025年第1期115-123,I0005,共10页稀土学报(英文版)

摘　　要：The present work reports the structural,optical,dielectric,and electrical properties of Eu-Er substituted M-type Ba_(0.5)Sr_(0.5)Eu_(x)Er_(x)Fe_(12-2x)O_(19)(x=0.0.05,0.1,0.15,and 0.2)hexaferrites synthesized by sol-gel combustion method.The hexagonal structure of the Ba_(0.5)Sr_(0.5)Eu_(x)Er_(x)Fe_(12-2x)O_(19) samples was confirmed from X-ray diffraction(XRD)analysis.The values of lattice parameters of the Ba_(0.5)Sr_(0.5)Eu_(x)Er_(x)Fe_(12-2x)O_(19)samples are increased as compared to Ba_(0.5)Sr_(0.5)Fe_(12)O_(19) sample.This increase in the value of lattice parameters is attributed to the substitution of larger cations(Eu^(3+)and Er^(3+))in place of smaller cations(Fe^(3+)ions).The crystallite sizes of the Ba0.5Sr0.5EuxErxFe12-2x019 samples also increase due to the substitution of larger cations.The force constants(K_o and K_t)increases with increasing Eu-Er concentration.The octahedral cluster shifts towards the higher wavenumber side whereas the tetrahedral cluster shifts towards the lower wavenumber side due to Eu-Er substitution in the Fourier transform infrared(FTIR)spectra.The photoluminescence(PL)emission spectra for the Ba_(0.5)Sr_(0.5)Eu_(x)Er_(x)Fe_(12-2x)O_(19) samples are observed at 365 nm.The dielectric dispersion in the Ba_(0.5)Sr_(0.5)Eu_(x)Er_(x)Fe_(12-2x)O_(19) samples can be understood by Koop's theory and Maxwell-Wagner type of inte rfacial polarization.Using Jonscher's power law and the co rrelated barrier hopping(CBH)model,the frequency and temperature-dependent be haviour of ac conductivity of Ba_(0.5)Sr_(0.5)Eu_(x)Er_(x)Fe_(12-2x)O_(19) samples are described.The temperature-dependent behaviour of the dc conductivity of the Ba_(0.5)Sr_(0.5)Eu_(x)Er_(x)Fe_(12-2x)O_(19) samples is explained by the variable range hopping(VRH)model.The Motto temperature of the sample varies from 4.55×10^(9) to 2.31×10^(8) K.The estimated maximum barrier height(WM)of the compound varies from 0.6603 to 0.1199 eV.The temperature coefficient and activation energy of the samples were also calculated as a funct

关 键 词：Sol-gel process POROSITY Dielectric properties Ferrites Rare earths 

分 类 号：O61[理学—无机化学]