Abstract:
From the similarity of the electronic configurations of the three transition series, similar magnetic behaviour should be expected. In each case, the incomplete sub shell lies outermost, which means that in solution or in the solid state the orbital contribution is reduced. Van Vleck (1) (1932) pointed out that complexes of the palladium and platinum series seemed to conform with neither the theory which explained magnetic behaviour of the rare earths nor the "spin only" theory which accounted for the iron compounds. He suggested that in the palladium and platinum series, the Hund Principle of maximum multiplicity is not obeyed.
Pauling(2) accounts for the lowering of the moment in terms of the effect of covalent bond formation on the number of unpaired electron spins. From this theory, he predicted the magnetic moments of the iron, palladium and platinum series, the Pauling predictions being given in Table I. For confirmation, he examined the iron, cobalt, nickel series, and reasonably good agreement was obtained.
