Synthesis and characterization of lanthanum-doped yttrium iro n garnet(YIG)in the compositional se ries of Y_(3-x)La_(x)Fe_(5)O_(12)(x=0.0,0.1,0.3,and 0.5)were carried out.All compositions were made by using solid sta...Synthesis and characterization of lanthanum-doped yttrium iro n garnet(YIG)in the compositional se ries of Y_(3-x)La_(x)Fe_(5)O_(12)(x=0.0,0.1,0.3,and 0.5)were carried out.All compositions were made by using solid state reaction method with ball-milling technique.The phase formation,surface morphology,magnetic properties,and microwave absorbing ability of all compositions were characterized by using an X-ray diffractometer,a scanning electron microscope,a vibrating sample magnetometer,and a Vector network analyzer.The results reveal that all compositions are crystallized into Y_(3)Fe_(5)O_(12)phase(space group la-3d(230).It was observed that the lattice constant is increased from 1.2373 to 1.2421 nm with the increase of lanthanum substitution level from x=0.0-0.5.The crystallite size of Y_(3-x)La_(x)Fe_(5)O_(12)series calculated by Scherrer method is found to decrease from 78 nm in x=0.0-63 nm in x=0.5.The particle size distribution from the surface morphology image analysis is shifted to lower-range number with the increase of lanthanum substitution level from x=0.0 to 0.5.The substitution process also affects the lattice distortion in La-doped samples and changes the bond angles and bond lengths of the YIG structure.As the results,a linear correlation between the Fe'-O-Fe bond angle with magnetic properties parameters of saturation magnetization(M_(s))and remanence magnetization(M_(r))was studied.Due to the lanthanum substitution process,all La^(3+)-doped samples possess higher M_(s)and M_(r)values compared to the original composition.The results of Vector network analyzer show that the improvement of the M_(s)and M_(r)plays an important role in enhancing the microwave absorbing ability of the materials.The minimum RL changes from-8.22 dB(~85.22%microwave absorption)in x=0.0 to-14.21 dB(~96.25%microwave absorption)in x=0.5.The enhancement is mainly ascribed to the natural magnetic resonance loss and dipoIe-polarization loss due to the substitution process.The decreasing particle size also enhances the microwave absorbing ability of the La-doped samples via multiple-reflections mechanism.展开更多
基金Project supported by the Ministry of Finance Indonesia for the research grant through the competitive research program of RISPRO Kompetisi(PRJ-45/LPDP/2020)。
文摘Synthesis and characterization of lanthanum-doped yttrium iro n garnet(YIG)in the compositional se ries of Y_(3-x)La_(x)Fe_(5)O_(12)(x=0.0,0.1,0.3,and 0.5)were carried out.All compositions were made by using solid state reaction method with ball-milling technique.The phase formation,surface morphology,magnetic properties,and microwave absorbing ability of all compositions were characterized by using an X-ray diffractometer,a scanning electron microscope,a vibrating sample magnetometer,and a Vector network analyzer.The results reveal that all compositions are crystallized into Y_(3)Fe_(5)O_(12)phase(space group la-3d(230).It was observed that the lattice constant is increased from 1.2373 to 1.2421 nm with the increase of lanthanum substitution level from x=0.0-0.5.The crystallite size of Y_(3-x)La_(x)Fe_(5)O_(12)series calculated by Scherrer method is found to decrease from 78 nm in x=0.0-63 nm in x=0.5.The particle size distribution from the surface morphology image analysis is shifted to lower-range number with the increase of lanthanum substitution level from x=0.0 to 0.5.The substitution process also affects the lattice distortion in La-doped samples and changes the bond angles and bond lengths of the YIG structure.As the results,a linear correlation between the Fe'-O-Fe bond angle with magnetic properties parameters of saturation magnetization(M_(s))and remanence magnetization(M_(r))was studied.Due to the lanthanum substitution process,all La^(3+)-doped samples possess higher M_(s)and M_(r)values compared to the original composition.The results of Vector network analyzer show that the improvement of the M_(s)and M_(r)plays an important role in enhancing the microwave absorbing ability of the materials.The minimum RL changes from-8.22 dB(~85.22%microwave absorption)in x=0.0 to-14.21 dB(~96.25%microwave absorption)in x=0.5.The enhancement is mainly ascribed to the natural magnetic resonance loss and dipoIe-polarization loss due to the substitution process.The decreasing particle size also enhances the microwave absorbing ability of the La-doped samples via multiple-reflections mechanism.
