Title of article :
Synthesis and electronic structure of proton-type partially substituted birnessite by period-four transition metal
Author/Authors :
Takei، نويسنده , , Takahiro and Dong، نويسنده , , Qiang and Yonesaki، نويسنده , , Yoshinori and Kumada، نويسنده , , Nobuhiro and Kinomura، نويسنده , , Nobukazu، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2011
Pages :
6
From page :
1896
To page :
1901
Abstract :
Partially substituted proton-type birnessite were prepared by solid state reaction and their structures were refined. The formed birnessite with no substitution is identified to rhombohedral phase. In the case of substitution treatment by V and Cr for Mn, birnessite phase was not formed. On substituting Fe, hexagonal phase increased with increase of the amount of the Fe. For Co and Ni-substitution, monoclinic phase emerged at substitution ratio of around 0.37 and 0.02, respectively. For the substitution of Cu, only the monoclinic birnessite formed irrespective of the ratio. The electric conductivity of the partially substituted birnessites was examined at room temperature. The general trend is lower conductivity with increasing ratio of contained substituents. On several mol% of the substitution by Ni and Cu, the conductivity slightly increased. From DOS calculation of these compounds, the partially substitution for Mn by Fe, Co and Ni in the birnessite poses splitting of crystal field to emerge new bands at around −1 and +1 eV by Mn(IV) 3d orbital.
Keywords :
A. Layered compounds , C. X-ray diffraction , D. Electrical properties , D. Electronic structure
Journal title :
Materials Research Bulletin
Serial Year :
2011
Journal title :
Materials Research Bulletin
Record number :
2101225
Link To Document :
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