The gyromagnetic effect for paramagnetic substances. II.—Results on salts of the iron group

Abstract

In a previous paper (referred to hereafter as Part I) a method for measuring the gyromagnetic ratio for paramagnetic substances was described. Owing to the smallness of the angular moment produced by a change in the magnetic moment of a paramagnetic substance, a low frequency resonance method was employed to build up the amplitude to a measurable magnitude. An account of the method of measurement and elimination of errors was given in detail. The results of experiments on one paramagnetic substance, Dy +++ in dysprosium oxide (Dy 2 O 3 ), showed the Landé splitting factor for this ion to be 1·28, which indicates that the magnetic moment arises from both orbital and spin contributions. This agrees well with the theoretical value 1·33, corresponding to the state 6 H 15/2 deduced by Hund as the most probable ground state of this ion. The present contribution deals with results on salts of the iron group. The magnetic susceptibilities range from 10 -5 to 10 -4 compared with 2·4 × 10 -4 in the case of the Dy 2 O 3 previously used. This necessitates a greater sensi­tivity than that used in Part I, and the means employed to achieve this are described below.