Single crystal growth of HoFe2 and ErFe2

The first single crystal growth of centimeter-dimension specimens of HoFe2 and ErFe2. These materials are cubic Laves phase compounds, which, as a class, exhibit such properties as magnetic anisotropy, large magnetostriction, and spin reorientations. The present crystals, of as much as 15 gm mass, make possible single crystal neutron diffraction and magnetostriction measurements. The starting compounds prepared from 99.9 percent rare earth ingot and 99.95 percent iron rod, were melted together in electric arc or radio frequency induction furnaces. Single crystals were grown by the Czochralski technique, using an electric arc-powered furnace, under gettered argon atmosphere. HoFe2 and ErFe2 behave as congruently melting compounds, and grow under similar conditions. The crystals produced have been examined by x-ray and neutron diffraction, which show (1) the absence of structure on the neutron diffraction rocking curve peaks and (2) mosaic spreads of not more than 0.30. The very high quality of the specimens obtained may be deduced from these results