Magnetic phase transitions in R2Fe17 compounds under pressure

The effect of the pressure up to 1.4 GPa on the Curie temperature T_c in the R₂Fe₁₇ intermetallics with R=Nd, Er and Y was measured using a low field susceptibility technique. The identical character of the temperature dependence of susceptibility X(T) of the R₂Pe₁₇ intermetallics observed at ambient pressure (sharp step-like drop at T_c) is preserved at high pressures only in the case of Nd₂Fe₁₇. Pronounced broadening and splitting of the sharp drop of X(T) was observed in Er₂Fe₁₇ and Y₂Fe₁₇ respectively. The initial pressure slopes of dTc/dp are large and negative for all studied compounds, having nearly the same values (dTc/dp=-36K/GPa for Nd₂Fe₁₇ compound). Our results are discussed from the point of view of the sensitivity of T_c on the crystal structure, the number of nearest neighbours of Fe atoms and the possible effect of “disordered” structures in the R₂Fe₁₇ intermetallics