Low dimensional magnetism in complex transition metal oxalate networks


Daniel Price
University of Glasgow

Time and Place

Thursday, 3 April 2014 - 11:00am
CSEC Seminar Room


The coordination chemistry of the oxalate dianion, C2O42- tends to show quasi-predictable local structures, which in turn are clearly linked to the variety of 3-D extended coordination network structures that we observed. Using moderately high temperature/pressure hydrothermal synthesis methods, we have been able to crystallise many new (low solubility) transition metal oxalate coordination networks. The generic features of these networks are a) that the number of oxalate bridged metal-metal linkages is low - at most 4 and b) that the metal-oxalate network has a confined spatial dimension (sometimes 3D, more often 2D or 1D). The local, geometrically predictable structure of the oxalate coordination is coupled with a well defined ability of the oxalate ion to mediate significant antiferromagnetic interactions between linked paramagnetic transition metal ions. This means that the materials that we form, are generally comprised of low-dimensional, (often low connectivity) magnetically coupled frameworks. We frequently observe a suppression of conventional long range magnetic ordering, making these materials candidates to show unusual quantum phases, such as Haldane antiferromagnetism. The talk will describe some of the low dimensional material that we form and look at the results of some preliminary magnetic studies.