Spontaneous formation of vanadium "molecules" in a geometrically frustrated crystal: AlV2O4.
We investigated the charge-ordered (CO) state in spinel AlV2O4 by electron diffraction, synchrotron x-ray diffraction, and magnetic measurements. It was found that the CO structure appearing below 700 K is characterized by the formation of V clusters (heptamers), each of which is consisting of 7 vanadium atoms and is in a spin-singlet state as a total. Theoretical consideration indicates that this unique molecularlike V heptamer is stabilized by a strong bonding of vanadium t(2g) orbitals.
Horibe
Y
Y
Department of Physics, Osaka Prefecture University, Osaka 599-8531, Japan.
Shingu
M
M
Kurushima
K
K
Ishibashi
H
H
Ikeda
N
N
Kato
K
K
Motome
Y
Y
Furukawa
N
N
Mori
S
S
Katsufuji
T
T