High pressure effect on magnetic properties and volume anomalies of Ce2Fe17

We present the results of high pressure studies of magnetization, magnetic phase transitions, and related volume anomalies for the intermetallic compound Ce2Fe17 under hydrostatic pressures up to 10 kbar. The giant negative pressure effect on the ferromagnetic ordering temperature Theta(T)=94 K was determined: d Theta(T)/dP = -(38 +/- 2) K/kbar. This extraordinary decrease of Theta(T) under pressure is not accompanied by the related pronounced decrease of the saturated magnetization under pressure below 2.5 kbar. The effect of pressure on the Neel temperature T-N = 206 K is less pronounced: dT(N)/dP = -(1.7 +/- 0.2) K/kbar. A large positive spontaneous volume magnetostriction that is observed below T-N is suppressed by the application of high pressure and it disappears above 2.5 kbar. A competition of positive and negative exchange interactions between iron atoms is discussed and is thought to be the main reason for the volume anomalies observed. The role of the f electrons of Ce, their possible hybridization with d states of Fe, and their role in magnetic properties of the Ce2Fe17 compound is not yet clear. (C) 1999 American Institute of Physics. [S0021-8979(99)01723-5].