DEUTERIDE ABSORPTION AND DESORPTION EFFECTS ON MAGNETIC-PROPERTIES OFYFE2DX

Citation
V. Paulboncour et al., DEUTERIDE ABSORPTION AND DESORPTION EFFECTS ON MAGNETIC-PROPERTIES OFYFE2DX, Journal of applied physics, 79(8), 1996, pp. 4253-4259
Citations number
13
Categorie Soggetti
Physics, Applied
Journal title
ISSN journal
00218979
Volume
79
Issue
8
Year of publication
1996
Part
1
Pages
4253 - 4259
Database
ISI
SICI code
0021-8979(1996)79:8<4253:DAADEO>2.0.ZU;2-7
Abstract
Magnetic properties of YFe2 and its deuterides YFe2Dx have been invest igated in the temperature range 300 < T < 800 K. Both the lattice stru cture and the Curie temperature T-c show strong dependence on the deut erium composition x. The deuterides have a C15 cubic structure up to x = 2.7 and T-c rises from 560 K for x = 0, up to 715 K for x = 2.2 and 2.7. Amorphous YFe2D2.3 was also synthetized and surprisingly display s a lower T-c = 330 K. For larger deuterium concentrations, the deuter ides show a rhombohedral distortion and the Curie temperature is reduc ed. Rhombohedral deuteride YFe2D3.6 has T-c = 345 K. Heating this deut eride above 410 K leads to partial desorption of the deuterium and tra nsformation of the material into a cubic phase. This is evidenced by t he fact that a spontaneous magnetization at these high temperatures is restored, characteristic of cubic deuterides with x less than or equa l to 2.7. On the other hand, additional desorption upon heating above 700 K induces a transition to the amorphous state, as a result of the weakening of the Y-Fe bond. The time dependence of the magnetization a t a given temperature shows that the desorption at high temperature is due to the diffusion of deuterium through the surface. (C) 1996 Ameri can Institute of Physics.