Metal insulator phase transition and magnetic properties of VnO2n-1

Magnetic properties of V
n
O
2n-1
system, which shows the temperature induced metal insulator phase transition at T
t
, were studied by the measurement of magnetic susceptibility and Mössbauer effect. It was observed that V
3
O
5
, V
4
O
7
, V
5
O
9
, V
6
O
11
, V
7
O
13
, and V
8
O
15
order anti-ferromagnetically at 70, 40, 30, 23, 51, and 7 K, respectively. V
3
O
5
behaves like a low dimensional antiferromagnet. V
7
O
13
is a metallic antiferromagnet. Above T
t
(metallic phase) the total susceptibility χ
mol
can be represented by χ
mol
= C
obs
/ T-θ + χ
0
. C
obs
is in a good agreement with calculated value C
cal
, assuming that the material is ionic (V
⁺³
and V
⁺⁴
in a paramagnetic state). Density of electronic state of Fermi level
D_{(\epsilon_{f})_{x}_{0}
was calculated from χ
0
assuming Pauli paramagnetism and compared with the
D_{(\epsilon_{f})_\gamma
obtained by specific heat measurement.