Kinds Of Copper Research Articles

Cathodic erosion in the vacuum arc

The cathodic erosion of Cu, Cr and Cd has been measured at DC currents below 2000 A, and was found to be, to a first approximation, dependent on the total charge passed through the arc only. The observed erosion rates were 76, 22 and 400 μg C−1 for Cu, Cr and Cd respectively.Measurements on different kinds of copper indicate that the crystal grain size is of influence on the erosion rate.Of the total energy dissipated in the arc, about 25% is transferred to the cathode and 75% is divided between the losses to the surroundings and input to the anode. An attempt is made to correlate the erosion rate to one or more of the material properties of the metal.

Absorption spectra of some mixed chelates of copper(II)

Spectrophotometric study of aqueous solutions containing two kinds of copper(II) chelates ([Cu A 2] ± a and [Cu B 2] ± b ; A and B = en, gly, bip, phen or ox) revealed the formation of mixed chelates [Cu gly en] +, [Cu en bip] 2+, [Cu en phen] 2+, [Cu gly bip] +, [Cu gly phen] +, [Cu ox bip] and [Cu ox phen]. Their formation constants are, in most cases, relatively high, and their visible absorption spectra do not obey the rule of Kida. This spectral anomaly can be explained by the existence of a strong steric hindrance in the formation of [Cu bip 2] 2+ and [Cu phen 2] 2+ and its absence in the formation of the mixed chelates. All these mixed species (except for [Cu gly en] +) were also obtained as solid complexes (perchlorates and nitrates in the case of cationic species), which were characterized by their X-ray diffraction patterns and powder reflection spectra. The chelate of the composition Cu ox bip was found to exist in two modifications, one of which seems to be formulated as [Cu bip 2] [Cu ox 2].