Novel organic-inorganic layered oxide with spin ladder structure

Abstract

Structural analysis of a layered manganese tungstate diaminoalkane hybrid series suggests that this compound forms a spin-5/2 spin-ladder structure. We use X-ray diffraction, electron microscopy and x-ray absorption spectroscopy results to infer the structure. DC magnetization of the manganese compound and a possible copper analogue appear to show that the manganese system behaves like 1-dimensional antiferromagnetic Heisenberg chains (i.e. $J_{\parallel }\gg J_{\perp })$ while the copper system is fitted well by a $S=1/2$ spin ladder model, giving the parameters $g=1.920\pm 0.008$, $J_{\parallel }/k_B=-0.3\pm 1.4$K; $J_{\perp }/k_B=213.6\pm 1.1$K. The ability to tune adjacent inorganic layers of the hybrid materials by altering the length of the organic `spacer' molecules gives enormous promise for the use of these materials, especially when doped, to provide a greater understanding of spin ladder systems.

7 pages, 9 figures