Three metal molybdate hydrates,Fe（H2O） 2（MoO4）2·H3O（FeMo）,NaCo 2（MoO4） 2（H3O2）（CoMo） and Mn 2（MoO4）3·2H3O（MnMo）,were synthesized by the mixed-solvent-thermal methods and characterized by sing...Three metal molybdate hydrates,Fe（H2O） 2（MoO4）2·H3O（FeMo）,NaCo 2（MoO4） 2（H3O2）（CoMo） and Mn 2（MoO4）3·2H3O（MnMo）,were synthesized by the mixed-solvent-thermal methods and characterized by singlecrystal X-ray diffraction.X-Ray photoelectron spectroscopy and bond-valence sums were applied to confirming the valance of Fe,Co,Mn and Mo.Thermo-gravimetric analysis and X-ray powder diffraction measurements indicate that the samples were converted to different structural compounds upon heating in air at 600 ℃ for 1 h.The magnetic properties of these compounds were studied.The dominant magnetic interactions are antiferromagnetic in nature.However,different synthesis conditions led to the diversity of magnetic properties of compound CoMo.展开更多
Transition metal molybdate(RMoO4)has been extensively studied in optics,electricity and catalysis due to its low cost and multivalent Mo atoms,while its poor electrical conductivity limits its application in electroma...Transition metal molybdate(RMoO4)has been extensively studied in optics,electricity and catalysis due to its low cost and multivalent Mo atoms,while its poor electrical conductivity limits its application in electromagnetic wave absorption(EMA).Compounding molybdate with conductive materials is an effective way to improve its electrical conductivity.In this work,a homogeneous coating on the molybdate surface was achieved by utilizing a pyrrole oxidation polymerization mechanism,and then stabilized composites of Molybdate@Carbon(RMoO4@C)were obtained by high-temperature pyrolysis.The EMA properties of the nanocomposites were tuned by substituting the species of transition metal elements(RMoO_(4)@C,R=Fe,Co,Cu).Among them,Fe_(2)(MoO_(4))_(3)@C has a minimum reflection loss of−60.62 dB at an ultra-low thickness of 1.7 mm,and the effective absorption bandwidth(EAB)can reach 4.75 GHz at 3.00 mm.This work expands the range of applications for molybdate and provides a new material basis for building high-performance EMA materials.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.20971054,90922034)the Key Project of the Ministry of Education of China(No.2009-49)
文摘Three metal molybdate hydrates,Fe（H2O） 2（MoO4）2·H3O（FeMo）,NaCo 2（MoO4） 2（H3O2）（CoMo） and Mn 2（MoO4）3·2H3O（MnMo）,were synthesized by the mixed-solvent-thermal methods and characterized by singlecrystal X-ray diffraction.X-Ray photoelectron spectroscopy and bond-valence sums were applied to confirming the valance of Fe,Co,Mn and Mo.Thermo-gravimetric analysis and X-ray powder diffraction measurements indicate that the samples were converted to different structural compounds upon heating in air at 600 ℃ for 1 h.The magnetic properties of these compounds were studied.The dominant magnetic interactions are antiferromagnetic in nature.However,different synthesis conditions led to the diversity of magnetic properties of compound CoMo.
基金the National Natural Science Foundation of China(No.52273267)the Fundamental Research Funds for the Central Universities(No.30920041102)。
文摘Transition metal molybdate(RMoO4)has been extensively studied in optics,electricity and catalysis due to its low cost and multivalent Mo atoms,while its poor electrical conductivity limits its application in electromagnetic wave absorption(EMA).Compounding molybdate with conductive materials is an effective way to improve its electrical conductivity.In this work,a homogeneous coating on the molybdate surface was achieved by utilizing a pyrrole oxidation polymerization mechanism,and then stabilized composites of Molybdate@Carbon(RMoO4@C)were obtained by high-temperature pyrolysis.The EMA properties of the nanocomposites were tuned by substituting the species of transition metal elements(RMoO_(4)@C,R=Fe,Co,Cu).Among them,Fe_(2)(MoO_(4))_(3)@C has a minimum reflection loss of−60.62 dB at an ultra-low thickness of 1.7 mm,and the effective absorption bandwidth(EAB)can reach 4.75 GHz at 3.00 mm.This work expands the range of applications for molybdate and provides a new material basis for building high-performance EMA materials.
