High-pressure neutron and magnetization investigations of the magnetic ordering in CeSb

High-pressure magnetization and neutron-diffraction experiments have been performed on CeSb under hydrostatic pressure up to 21 kbar in the temperature range 3–32 K. The magnetic ordering in CeSb is very sensitive to hydrostatic pressure. The Néel temperature ${\mathit{T}}_{\mathit{N}}$ changes from 16 K at P=1 bar to 31 K at P=21 kbar. The stability ranges in temperature of the so-called antiferroparamagnetic (AFP) phases decrease continuously with pressure and disappear completely above P=10 kbar. At P=2.5 kbar, the type-I phase stabilizes at ${\mathit{T}}_{\mathit{N}}$ and the transition at ${\mathit{T}}_{\mathit{N}}$ crosses over from first to second order giving rise to the critical end point at P=2.5 kbar, T=18 K. At P=10 kbar two phases with magnetic ordering sequences (++--+-) and (++--+--++-) of the ferromagnetic (010) planes are successively observed between type-I and type-IA phases. The results have been discussed in terms of the p-f mixing model.