The spatial distribution of the paramagnetically aligned moments in the high-temperature insulating phase of V2O3

The spatial distribution of the magnetization induced in V2O3 at 600 K by a field of 9 T has been determined using polarized neutron diffraction. At t his temperature V2O3 has the rhombohedral corundum structure and behaves as an insulator, whereas at lower temperature the same structure exhibits met allic conduction. The susceptibilities of the conducting and insulating sta tes are similar, similar or equal to 10(-5) emu g(-1), and the moment align ed by 9 T at 600 K is 0.014 mu (B)/V. The magnetic structure factors were d etermined from the polarization dependence of the intensities of the Bragg reflections. The results show that there is a significant change in the par amagnetic moment distribution between 180 K and 600 K. At the higher temper ature the moment distribution around the V atoms has nearly cylindrical sym metry about the triad axis. The negative moment associated with the oxygen sites which was induced at 180 K was also found at 600 K where it amounts t o some 5% of the total moment.