“…When the nominal composition is slightly Co rich (in addition to sufficient Ce, for example, Ce 0.5 Co 4.2 Sb 11.8, red empty triangle) the sample is in the three-phase region between CoSb 2 , Ce-CoSb 3 (ref. 23 ) and Ce x Co 4 Sb 12 with x =0.120±0.005 (red point). Also if the nominal composition is slightly Sb rich (for example, Ce 0.5 Co 3.9 Sb 12.1, yellow empty triangle) the sample is in the three-phase region between CeSb 2 , Ce-CoSb 3 and Ce x Co 4 Sb 12 with, coincidentally, the same x =0.120±0.005 (red point) as found in the cobalt-rich three-phase region.…”