On the Magnetic Properties of Systems with Low Dimensional Linkage of VO_5 Pyramids

抄録

[N(CH₃)₄]V₃O₇, (en)₂ZnV₆O₁₄ (en=ethylenediamine) and(C₆H₁₄N₂)V₆O₁₄· H₂O withedge-sharing VO₅ chains have been prepared hydrothermally and studied bymagnetic susceptibility measurements and by NMR.Observed magnetic properties, which indicate the existence of the spin gap, can be explained by a model of isolated spin dimers of V⁴⁺ ions, where a very large exchange interaction J exists only betweenthe electrons at V sites within two edge-sharing VO₅ pyramidswhose apical oxygens are on the same side of the basal planes.It can be understood by considering the kinetic exchange mechanism actingbetween the electrons in the xy orbitals.