In this study,SrFe12-xTbxO19(0.00≤x≤0.1)hexaferrites(HFs)were prepared successfully by citrate solgel approach.X-ray powder diffraction analyses affirm the hexagonal structure of products.Impurity phase starts to ap...In this study,SrFe12-xTbxO19(0.00≤x≤0.1)hexaferrites(HFs)were prepared successfully by citrate solgel approach.X-ray powder diffraction analyses affirm the hexagonal structure of products.Impurity phase starts to appear for x≥0.04.The crystallites sizes were estimated to be in the range of 33-46 nm.All the products exhibit inhomogeneous distribution of grain size detected through SEM.The analyses of magnetization versus applied magnetic field,M(H),were performed.Magnetization measurements were done at room(300 K;RT)and low(10 K)temperatures.The different magnetic parameters including saturation magnetization Ms,remanence Mr,squareness ratio(SQR=Mr/Ms),coercivity Hc,and magnetic moment nB are deduced and discussed in detail.At both considered temperatures,M(H)results show ferrimagnetic nature for all compositions.It is shown that the Tb substitutions significantly affect M(H)data.A significant increase in the Ms,Mr,and nB is observed for x=0.02 sample.The SQR values are around 0.5 indicating the single domain nature with uniaxial anisotropy.The obtained magnetic results were investigated deeply with relation to structural and microstructural properties.Mossbauer spectroscopy results were also investigated.According to Mossbauer results,the Tb3+ions preferentially occupy 12 k and 4f2 sites.展开更多
In this comparative study,Tb and Tm substituted Sr-hexafe rrites(HFs) with the chemical compositions of SrTb_(x)Fe_(12-x)O_(19) and SrTm_(x)Fe_(12-x)O_(19)(x=0.00,0.02 and 0.04) were fabricated via citrate sol-gel app...In this comparative study,Tb and Tm substituted Sr-hexafe rrites(HFs) with the chemical compositions of SrTb_(x)Fe_(12-x)O_(19) and SrTm_(x)Fe_(12-x)O_(19)(x=0.00,0.02 and 0.04) were fabricated via citrate sol-gel approach.The AC susceptibility and FC-ZFC magnetization were investigated.The product structure and morphologies were also investigated via XRD,TEM and SEM along with EDX.Measurements of temperature dependence of magnetization M-T and AC magnetic susceptibility versus temperature were carried out.The various synthesized HFs displayed ferrimagnetic behavior within 10-325 K.At lower temperatures,super-spin glass-like behavior was noticed.Neel-Arrhenius and Vogel-Fulcher models were employed to explore the experimental data of AC susceptibility.展开更多
基金Project supported by the Institute for Research&Medical Consultations(Projects application No.2017-IRMC-S-3,No.2018-IRMC-S-1 and No.2018-IRMC-S-2)the Deanship of Scientific Research(Projects application No.2017-576-IRMC and No.2018-209-IRMC)of Imam Abdulrahman Bin Faisal University(Saudi Arabia).
文摘In this study,SrFe12-xTbxO19(0.00≤x≤0.1)hexaferrites(HFs)were prepared successfully by citrate solgel approach.X-ray powder diffraction analyses affirm the hexagonal structure of products.Impurity phase starts to appear for x≥0.04.The crystallites sizes were estimated to be in the range of 33-46 nm.All the products exhibit inhomogeneous distribution of grain size detected through SEM.The analyses of magnetization versus applied magnetic field,M(H),were performed.Magnetization measurements were done at room(300 K;RT)and low(10 K)temperatures.The different magnetic parameters including saturation magnetization Ms,remanence Mr,squareness ratio(SQR=Mr/Ms),coercivity Hc,and magnetic moment nB are deduced and discussed in detail.At both considered temperatures,M(H)results show ferrimagnetic nature for all compositions.It is shown that the Tb substitutions significantly affect M(H)data.A significant increase in the Ms,Mr,and nB is observed for x=0.02 sample.The SQR values are around 0.5 indicating the single domain nature with uniaxial anisotropy.The obtained magnetic results were investigated deeply with relation to structural and microstructural properties.Mossbauer spectroscopy results were also investigated.According to Mossbauer results,the Tb3+ions preferentially occupy 12 k and 4f2 sites.
文摘In this comparative study,Tb and Tm substituted Sr-hexafe rrites(HFs) with the chemical compositions of SrTb_(x)Fe_(12-x)O_(19) and SrTm_(x)Fe_(12-x)O_(19)(x=0.00,0.02 and 0.04) were fabricated via citrate sol-gel approach.The AC susceptibility and FC-ZFC magnetization were investigated.The product structure and morphologies were also investigated via XRD,TEM and SEM along with EDX.Measurements of temperature dependence of magnetization M-T and AC magnetic susceptibility versus temperature were carried out.The various synthesized HFs displayed ferrimagnetic behavior within 10-325 K.At lower temperatures,super-spin glass-like behavior was noticed.Neel-Arrhenius and Vogel-Fulcher models were employed to explore the experimental data of AC susceptibility.
