MAGNETIC-PROPERTIES OF CU-2(OH)(3)(ALKANECARBOXYLATE) COMPOUNDS - DRASTIC MODIFICATION WITH EXTENSION OF THE ALKYL CHAIN

Magnetic properties of the layered materials Cu-2(OH)(3)(n-C(m)H2(m+1) COO) (m = 0, 1, 7, 8, and 9) have been examined. X-ray powder diffract ion patterns indicate that the interlayer distance increases in the or der of In. The interlayer distances of the m = 0 and 1 materials are s horter than the molecular heights of the intercalated carboxylates, re spectively, while the distances of the m = 7-9 materials are nearly do uble those of the molecular heights of the corresponding carboxylates, indicating a bilayer structure in them. The temperature dependence of the paramagnetic susceptibilities of the m = 0 and 1 materials sugges ts an intralayer ferromagnetic interaction and an interlayer antiferro magnetic interaction. The metamagnetic behavior is supported by S-shap e dependence of their magnetization curves. The temperature dependence of the paramagnetic susceptibilities of the m = 7-9 materials indicat es an intralayer antiferromagnetic interaction, in opposition to those in the former two. Further, they show a divergence of the ac magnetic susceptibility at 22 K, indicating a ferromagnetic order. The magneti zation curve is characterized by an immediate increase at lower fields , succeeded by a gradual increase without saturation at higher fields. The magnetic properties of the m = 7-9 materials are well understood in terms of the weak ferromagnetism. The change of the intralayer magn etic interaction could be caused by some structural change in the CuOH layer with the intercalation.