Tuning of electronic structures of quasi-one-dimensional bromo-bridged Ni(III) complexes with strong electron-correlation by doping of Co(III) ions, [Ni(1-x)Co(x)(Chxn)(2)Br]Br(2).
We have succeeded in synthesizing the Ni(III) complexes doped by Co(III) ions, [Ni(1-x)Co(x)(chxn)(2)Br]Br(2) (x = 0, 0.043, 0.093, and 0.118) by using an electrochemical oxidation method. The single-crystal reflectance spectrum of x = 0.118 shows an intense CT band about 0.5 eV, which is lower than that of [Ni(chxn)(2)Br]Br(2) (1.3 eV). The single-crystal electrical conductivities at room temperature of these compounds increase with increase of the amounts of doping of Co(III) ions. In the ESR spectra, peak-to-peak line widths DeltaH(pp) at room temperature change about 600 G in [Ni(chxn)(2)Br]Br(2) to 200 G in x = 0.118. Such a large x dependence of DeltaH(pp) seems to be ascribed to the increasing contribution from the increasing Curie spins which have smaller line width. Therefore, we have tuned the electronic structures of quasi-one-dimensional bromo-bridged Ni(III) complexes with strong electron correlations by doping of Co(III) ions.
Yamashita
M
M
Graduate School of Science, Tokyo Metropolitan University and PRESTO (JST), 1-1 Minamiohsawa, Hachioji, Tokyo 192-0397, Japan. yamashit@comp.metro-u.ac.jp
Yokoyama
K
K
Furukawa
S
S
Manabe
T
T
Ono
T
T
Nakata
K
K
Kachi-Terajima
C
C
Iwahori
F
F
Ishii
T
T
Miyasaka
H
H
Sugiura
K
K
Matsuzaki
H
H
Kishida
H
H
Okamoto
H
H
Tanaka
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H
Hasegawa
Y
Y
Marumoto
K
K
Ito
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H
Kuroda
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