Magnetic properties of the Ce2Fe17-xMnx helical magnets up to high magnetic fields

Magnetic properties of the Ce2Fe17-xMnx, x = 0-2, alloys in magnetic fields up to 40T are reported. The compounds with x = 0.5-1 are helical anti ferromagnets and those with I < x <= 2 are helical ferromagnets or helical antiferromagnets at low and high T, respectively. Mn ions in the system carry average magnetic moment of 3.0 +/- 0.2 YB that couple antiparallelly to the Fe moments. Easy-plane magnetic anisotropy in the Ce2Fe17-xMnx compounds weakens upon substitution of Mn for Fe. The absolute value of the first anisotropy constant in the Ce2Fe17-xMnx helical ferromagnets decreases slower with increasing temperature than that calculated from the third power of the spontaneous magnetization. Noticeable magnetic hysteresis in the Ce2Fe17-xMnx x = 0.5-2, helical magnets over the whole range of magnetic fields reflects mainly irreversible. deformation of the helical magnetic structure during the magnetization of the compounds. A contribution from short-range order (SRO) magnetic clusters to the magnetic hysteresis of the helical magnets has been also estimated. (C) 2007 Elsevier B.V. All rights reserved.