Thermal lattice expansion and out-of-plane relaxation of bcc-Co in Fe/Co multilayers observed with perturbed angular correlation spectroscopy
Instituut voor Kern- en Stralingsfysica, K. U. Leuven - 3000 Leuven, Belgium
Accepted: 14 February 1997
We report on the temperature dependence of the magnetic hyperfine field in bcc-Co as measured in Fe/Co multilayers. An anomalous increase of the hyperfine field with temperature is observed. Below the growth temperature of the samples, the behaviour can be explained by simple thermal expansion of the lattice. At 570 K a relaxation of the interplanar distance accounts for the anomaly. This relaxation is interpreted as an onset to the degeneration of the forced bcc structure to an energetically more favorable Co-phase.
PACS: 65.70.+y – Thermal expansion and density changes; thermomechanical effects / 68.65.+g – Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties / 76.80.+y – Moessbauer effect; other gamma-ray spectroscopy
© EDP Sciences, 1997