Abstract
300-Å Gd films grown on W(110) under UHV conditions have been investigated Iin situR by ac-susceptibility measurements above and below . A sharp peak of =230 is observed. To our knowledge, this is the largest and sharpest (2σ=1 K) cusp measured for a rare-earth ferromagnet. No domain-wall signal is superimposed upon the divergence of the paramagnetic susceptibility. At we find χ= with γ=1.235(25). This is clear evidence for a three-dimensional Ising-like behavior above . The sharpness and peak position of χ(T) change, depending on the annealing temperature. Simultaneously, a change in the LEED pattern is observed.
- Received 21 August 1991
DOI:https://doi.org/10.1103/PhysRevB.45.503
©1992 American Physical Society