Pure CuCl Research Articles

Zeeman Effect of the Exciton Bands of CuCl-CuBr Solid Solutions

Magnetic circular dichroism (hereafter abbreviated as MCD) spectra of the two exciton absorption bands at the absorption edge of CuCl, CuBr and solid solutions of CuCl and CuBr were measured. The MCD spectra of a solid solution having a small separation of the exciton absorption bands showed a strong magnetic field-induced interaction between the two exciton states. The MCD spectra of the higher energy exciton absorption band in pure CuCl and in a solid solution with low concentration of Br showed a negative g -value. This negative g -value of exciton absorption band is explained by theory similar to that used in explaining the negative value of spin-orbit interaction of CuCl, and is attributed to the mixing of the d orbital of Cu + with the p orbital of halogen ions.

Thermoelectric Power of CuCl Containing CdCl2

The thermoelectric power of CuCl has been measured as a function of temperature between 200° and 400°C, using Cu-metal electrodes. Measurements were made on pure material, and also on material doped with CdCl2 in concentrations between 0.01 and 1.0 mole %. The results for pure CuCl are intermediate between previous results for AgBr and AgCl, and the effect of doping is very similar to that in AgBr. Comparison of the CuCl results with those for the silver halides suggests that in CuCl cation Frenkel defects are predominant, with the Cu+ interstitial more mobile. Quantitative values for the defect parameters could not be derived, apparently because of the limited solubility of CdCl2, but they are probably comparable with the silver halides. Additions of CaCl2, SrCl2, ZnCl2, and PbCl2 gave less informative results; PbCl2 showed what is believed to be an electronic effect at high temperatures. Conductivity measurements were also made on all specimens. The activation energy for pure CuCl was 1.06 eV.

Mechanism of Electrical Conduction in Molten Cu S-Cu Cl and Mattes

The specific conductance and its temperature dependence were measured over the entire composition range of the molten Cu2S-CuCI system. At a typical temperature of 1200°C, 10 mol pct of the ionically conducting CuCl reduced the specific conductance from about 77 ohm−1cm−1 for pure Cu2S to about 32 ohm−1cm−1, and 50 mol pct CuCl reduced the conductance to that for pure CuCl—about 5 ohm−1cm−1. The nature of electrical conduction in molten Cu2S, FeS, CuCl, and mixtures was studied by measuring the current efficiency of electrolysis at about 1100°C. The Cu2S, FeS, and mattes were found to conduct exclusively by electrons, but addition of 15 wt pct CuS to Cu2S produces a small amount of electrolysis. Addition of CuCl to Cu2S suppresses electronic conduction, and ionic conduction reaches almost 100 pct at a CuCl concentration of about 50 mol pct. These facts are interpreted in terms of electron energy level diagrams by analogy to the situation in solids.