ESR studies of inter- and intra-lamellar cation exchange processes in Cd2P2S6

The transition metal chalcogenides, M2P2S6 (M = divalent transition metal cation), are lamellar materials that undergo an unusual cation exchange process when their crystals are placed in contact with a solution of a transition metal salt. EPR spectroscopy has been used to examine the exchange of paramagnetic Co2+ for Cd2+ in diamagnetic Cd2P2S6. It has been possible to study the uptake of ions by the lamellar lattice and to examine the cation coordination environment through its effect on the parameters of the spin-Hamiltonian. In order to extract details of the Co2+ coordination from the observed EPR spectra, theoretical values of the g-value have been computed as a function of several crystal field parameters. The results for Co2+ are compared with previous results for the insertion of Mn2+ into Cd2P2S6 by cation exchange. The relative occupancy of the inter- and intra-lamellar sites is a function of the cation type and the solvent employed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28953/1/0000790.pd

Quid pro quo:reflections on the value of problem structuring workshops

Attracting clients who are willing to invest in using a problem structuring method (PSM) can be particularly difficult for the emerging generation of modellers. There are many reasons for this, not least that the benefits of a problem structuring intervention are vague and evidence of benefits are often anecdotal for example, claims of constructing a deeper understanding of the problem or building the commitment of a group to implementing an outcome. This paper contributes to the evaluation of problem structuring methods by reflecting on the quid pro quo that a client and problem structuring modeller can enjoy from collaboration. The paper reflects on 21 cases, where Journey Making (a problem structuring method) was used with 16 organizations to help managers agree a suite of actions to tackle a complex strategic issue. The reflections are clustered around those benefits that pertain to: PSMs in general; PSMs that use computer-supported workshops; the Journey Making methodology