Thin spin reorientation

The possibility to perform nuclear resonant scattering experiments in situ has allowed for observation of a thickness-driven spin reorientation transition in thin epitaxial Fe film on W( 110) [78-80]. The time spectra of NRS were collected during continuous evaporation of Fe on a freshly cleaned W( 110) single-crystalline substrate oriented to 3.9 mrad with... 

By chromophore-polymer composite materials, we refer to chromophores physically incorporated (dissolved) into commercially available polymer materials such as amorphous polycarbonate (APC) [58] finm Aldrich Chemicals. Chromophore and polymer are dissolved in a suitable spin-casting solvent, such as cyclopentanone. Spin-cast thin films are heated to near the glass transition temperature of the composite material (which will vary with chromophore concentration due to the plasticizing effect of the chromophore). Acentric chromophore order is induced by electric field poling. If one assumes that the presence of the polymer host does not stericaUy hinder the reorientation of the chromophores under the influence of the poling field, the order parameter can be readily calculated. We have already noted that if chromo-phore-chromophore intermolecular electrostatic interactions are neglected then (cos d) = fiF/5kT and the order parameter will be independent of chromophore concentration (or number density, N). Intermolecular electrostatic interactions can be treated at several levels of sophistication. 

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