Pressure induced non-collinear magnetic structures in Fe-rich intermetallics

摘要

The results of a complementary study of magnetic properties, magnetovolume effects and neutron diffraction studies under pressure in R{sub}2Fe{sub}17 compounds with non-magnetic R (R-Y, Ce, Lu) are presented. The collinear ferromagnetic phase existing at low temperature in all three compounds is suppressed at high pressures. The critical pressure P{sub}C depends on the compound studied (P{sub}C≌2.5 kbar for Ce{sub}2Fe{sub}17, P{sub}C≌3.5 kbar for Lu{sub}2Fe{sub}17,P{sub}C≌12 kbar for Y{sub}2Fe{sub}17). Incommensurate non-collinear magnetic structures that replace the ferromagnetic ones under high pressures have similar features - magnetic moments in each layer of atoms (perpendicular to z-axis) are parallel each other, their direction helically changes from layer to layer. A generalized phase diagram of the studied R{sub}2Fe{sub}17 compounds was determined with use of the recent compressibility data.