Electrochemical behavior of Am at liquid Cd electrode

Hayashi, Hirokazu ; Akabori, Mitsuo; Minato, Kazuo ; Haire, R. G.*

The electrochemical behavior of Am at a liquid Cd cathode and the alloying behavior of Am with Cd were analyzed. In the cyclic voltammograms obtained with Mo electrode, the redox reactions of Am(III)/Am(II) and Am(II)/Am were observed, while peaks assigned to Am(III)/Am (in Cd) were observed with liquid Cd electrode. The observed electric potentials for the peaks with liquid Cd electrode were more positive than those with Mo electrode. The difference in the potentials E(Am-Cd) was 0.39V, which is similar to E(Pu-Cd) and much larger than E(U-Cd) and E(Np-Cd). It is reported that E(An-Cd) (An=U, Np, Pu) corresponds to G of An-Cd compound formed at Cd electrode (UCd, NpCd, PuCd). On the other hand, to identify the stable chemical form on Am-Cd phase diagram, Am-Cd intermetallic compounds were prepared by heating Am metal with liquid Cd. The product prepared by heating at 723K was identified as cubic AmCd with a=1.559 0.002 nm by powder X-ray diffraction. AmCd is considered to be formed at Cd electrode on the electrochemical experiments because it is the stable product at 723K.