EPITAXIAL-GROWTH OF CUBIC LAVES PHASE INTERMETALLIC COMPOUNDS (YCO2, TBCO2) AND NEW EPITAXIAL RELATIONSHIP BETWEEN FCC(111) AND BCC(110)

YCo2 and TbCo2 Laves phase compounds were epitaxially grown on (110) W buffer layers by. pulsed laser deposition at a base pressure of 5 x 1 0(-10) Torr and a substrate temperature of 500 degrees C. The films we re characterized in situ by reflection high-energy electron diffractio n, and after deposition by grazing-incidence x-ray diffraction and sca nning electron microscopy. The relative orientation of the RCo(2)(111) , where R = Y or Tb, and the W(110) planes was found to be unlike any previously observed relationship between fee and bcc materials. Two in -plane crystallographic domains of RCo(2)(111) have been pointed out a nd are discussed in terms of geometrical lattice matching. (C) 1996 Am erican Institute of Physics.