Abstract: Smooth coherent metal chalconide film is electroplated onto a cathode from an electroplating bath comprising a solution in an organic polar solvent metal salt and elemental chalcogen at elevated temperature and low current density.

Abstract: Metal chalconide films having improved photo-electrical properties are obtained from electrodeposition baths containing solvents having a low power for solvating metal cations such that decreased quantities of solvent molecules become intercalated into the chalconide film.

Abstract: The production of an ultra-hard particle composed substantially of carbon as the dominant element is taught. The ultra-hard particle is the product of the reaction of a metal carbide selected from the group consisting of Al.sub.4 C.sub.3 and Be.sub.2 C with a member selected from the group consisting of CH.sub.n X.sub.A Y.sub.(4-n)-A' C.sub.2 H.sub.n' X.sub.A' Y.sub.(6-n')-A', C.sub.2 H.sub.n" X.sub.A" Y.sub.(4-n")-A" and X.sub.2 wherein X and Y are different halogens selected from the group consisting of chlorine, bromine, iodine and fluorine, and wherein A is an integer from 0 to 4, A' is an integer from 0 to 6 and A" is an integer from 0 to 4, and wherein n is an integer from 0 to 4, n' is an integer from 0 to 6 and n" is an integer from 0 to 4, wherein A, A', A", n, n' or n" is the same integer in any particular member selected and wherein n+A=4, n'+A'= 6 and n"+A"=4.