Spontaneous magnetostriction of Ce2Fe17

X-ray diffraction study of the thermal expansion of Ce2Fe17 showed large po sitive spontaneous linear (lambda(a) and lambda(c)) and volume (omega(s)) m agnetostrictions resulting in the Invar effect in a wide temperature range below approximate to 250 K. At 10 K, lambda(a)=3.0x10(-3), lambda(c)=3.5x10 (-3), and omega(s)=9.5x10(-3). Transition from the ferro- to the antiferrom agnetic state reduces the magnetostrictions, slightly for lambda(c) and str ongly for lambda(a), leading to a more pronounced anisotropy of the spontan eous magnetostriction. (C) 2000 Elsevier Science S.A. All rights reserved.