Highly Anisotropic Pressure Dependence of the Fermi Surface of CeSb

We report a de Haas–van Alphen effect study of CeSb under pressure in the ferromagnetic phase. The frequencies of the electron Fermi surfaces and one particular hole surface increase considerably with increasing pressure, while those of the other hole surfaces decrease slightly. On the other hand, the effective masses increase similarly for all the hole surfaces with pressure, while those of the electron surfaces change little. The frequency changes seem to be explained qualitatively by considering the anisotropic $p$- $f$ mixing model. However, it is difficult to understand the changes of the effective masses in terms of the $f$ content expected for the $p$- $f$ mixing model.