SURFACE DEFORMATIONS AND DOMAINS IN TERFENOL-D BY SCANNING PROBE MICROSCOPY

This paper reports the first direct measurements of the deformations i n the surface of a ferromagnet caused by magnetostrictive lattice stra ins in neighboring magnetic domains. Observations of the {011} and {11 2} surfaces of twinned Terfenol-D (Tb0.3Dy0.7Fe2) crystals by atomic f orce microscopy reveal the deformation domains previously imaged by op tical microscopy and predicted by recent theory. The surface topograph y has been imaged in the remanent and ac demagnetized states and measu rements of the deformation gradients have enabled the magnetostriction constant in the (111) direction to be estimated as 1.63x10(-3) to wit hin 8%. All theoretically predicted deformation domains have been obse rved and, in particular, the exact compatibility of such deformations across the growth twin boundaries is clearly revealed. The magnetic do mains associated with the observed deformations are inferred from magn etic force microscopy observations which yield complex contrast patter ns. (C) 1995 American Institute of Physics.