Low-dimensional magnetism and related properties of VOMoO4

Powder X-ray, neutron diffraction and Raman scattering were measured in VOM oO4. The bond length between the V and O sites along the c-axis shows a min imum at around 100 K, Shrinkage of MoO4 tetrahedra with decreasing temperat ure was observed. The Raman peak near 380 cm(-1) splits into two peaks at l ower temperatures. This reflects the growth of an unharmonic phonon mode in the V-O bond, Molecular orbital calculation shows that the band overlap be tween V and MoO4 tetrahedra is small near the Fermi level. Results suggest a V-O chain like structure of this compound. The previously reported 1D mag netic behavior is related to the observed phonon mode. (C) 2000 Elsevier Sc ience B.V. All rights reserved.