The principal paramagnetic susceptibilities of potassium ferricyanide at low temperatures

The author's previous measurements of the principal magnetic susceptibilities of potassium ferricyanide have been repeated and extended to a temperature of 14.2° K. Two of the principal susceptibilities are approximately equal throughout the whole temperature range from 290 to 14° K., but that along the third principal axis is considerably smaller. The anisotropy is almost 400 per cent at 14° K. and is still increasing as the temperature falls. A brief comparison with Howard's theory of the magnetic properties of K 3 [Fe (CN) 6 ] is made.