Magnetic Properties of NaV₆O₁₁

XMCD and magnetism of the ferrimagnetic system NaV6O11

“…If the system is a ferromagnet, the full magnetic moments should be observed If, on the other hand, the coupling is antiferromagnetic, the deduced moment should be strongly reduced. The room temperature moment of NaV6Ott is 2.00 lab and the low temperature moment is 0.28 laB (Uchida 1991 ). If the system is purely ferrimagnetic, the white line intensity has to be reduced by a factor of 2.0 laB/0.28 lab = 7.14.…”

“…Below T,. and above 245K the behavior is metallic whereas it is semiconducting in between (Uchida 1991 ). XAS (above) and XMCD of NaV60~ at the V L2.3-and O K-edges…”

“…At temperatures above 245K NaV60~ is paramagnetic, belongs to the hexagonal spacegroup P63/mmc, shows a linear X ~ behavior and has an effective magnetic moment of 2.0laB. (Uchida 1991). Below 245K the symmetry is reduced to the hexagonal spacegroup P63mc.…”

Space-Group Determination of the Orthorhombic Form of NaV6O11

“…NaV6Oll shows two magnetic phase transitions at 64.2 K (= Tc) and 245 K (Kanke, Takayama-Muromachi, Kato & Matsui, 1990;Uchida et al, 1991). NaV6Oi i shows spontaneous magnetization below Tc and Curie-Weiss paramagnetism above 245 K (Uchida et al, 1991). NaV60 t 1 undergoes a second-order structural phase transition P63/mmc (high temperature)-P63mc (low temperature) at a temperature between 200 K and room temperature (Kanke et al, 1994).…”

“…Below Tc, NaV6O11 shows not only spontaneous magnetization but also metallic conductivity (Kanke et al, 1990;Uchida et al, 1991). Electric conductivity is governed by the band structure, which is influenced by the crystal symmetry.…”