Raman scattering from Pt(CN)42− adsorbed on Pt colloids

Raman scattering from Pt(CN)₄^2? adsorbed on Pt colloids (average diameter of 16 A) is compared with the Raman signal from the same amount of Pt(CN)₄^2? in solution. The wavelength dependence of the adsorbate Raman intensity is measured from 308 to 647 nm and compared with a Lorenz/Mie calculation of the enhancement factor for the electromagnetic field intensity on the surface of a Pt sphere as a function of sphere radius and incident wavelength.     

Radiation Effects on Concentrated Potassium Hexacyanoferrate(III) Solutions

The neutron irradiated potassium hexacyanoferrate(III) solutions were analyzed for Fe(CN)₆^4?, Fe(CN)₆^3?, and Prussian blue. The retention values (1.1%) were constant throughout the pH and concentration ranges studied, and did not change with the length of irradiation. The complex behavior of the radiochemical yield of the Fe(CN)₆^4? and Prussian blue was attributed to the competition of the various reactions involved in the irradiation.     

Strong-coupling effects in high-T c superconductors

It is conceivable that the high-T _c superconducting perovskites are conventional electronphonon superconductors. In this case one expects significant strong-coupling effects because of the unusually high ratiok _B T _c / of the order 0.1 and greater. We use a set of reasonable models for the Eliashberg function ² F() (which takes into account available information on the phonon spectra and which fit the measuredT _c 's) and calculate strong-coupling effects in the specific heatc _s (T)/T _c , the ratio ₀/k _B T _c , the critical fieldsH _c (T) andH _c2 (T) including Pauli limiting, and other measurable quantities. Strongcoupling corrections turn out to be in the range of 0 to about 100%, depending on the quantity of interest. We discuss the perspectives of using strong-coupling effects as indicators for conventional electron-phonon superconductivity in the new materials.