MAGNETIC DOMAINS AND MICROSTRUCTURAL DEFECTS IN TERFENOL-D

The ternary alloy Tb0.3Dy0.7Fe2 (Terfenol-D) is of significant technol ogical interest as it possesses the largest known magnetostriction to anisotropy ratio near room temperature. Results of microstructural and magnetic domain observations by Lorentz microscopy and reflection x-r ay topography are presented from both stoichiometric twinned single cr ystals prepared by a free-standing zoning technique, and pseudo single crystals prepared by the Czochralski method. Direct evidence of wall interactions with dislocations, twin boundaries and precipitates are p resented which demonstrate the complex interaction between the magneti c and strain energies within this material.