RECOVERY OF THE MAGNETIC-ORDERING IN Y1-XCEXMN2 INDUCED BY HYDROGEN ABSORPTION

The substitution of Ce by Y in YMn2 leads to the destabilization of th e Mn magnetic moment and inhibits both the transition to antiferromagn etism and the associated expansion of the crystal cell observed in pur e YMn2. We show in this work how hydrogen uptake in the Y1-xCexMn2 ser ies gives rise to the recovery of long-range magnetic ordering in thes e systems. The analysis of magnetic and x-ray-absorption spectroscopy experiments addresses the critical role played by the modification of the Ce electronic state in the stabilization of the Mn magnetic moment through the hybridization changes. [S0163-1829(98)02526-0].