“…In the first half of this century, new binary metal carbonyls of most of the transition elements were discovered, and each in turn was explored as a potential CVD precursor. Although Fe(CO) 5 and Co 2 (CO) 8 give reasonably pure iron [11 -13] and cobalt [14,15] metal at 200°C, other metal carbonyls such as chromium, molybdenum, or tungsten hexacarbonyl generally deposit films that contain mixtures of the pure metal, the metal oxide, the metal carbide, and graphitic carbon [16][17][18][19][20][21][22][23][24][25][26][27]. This is quite understandable, since carbon monoxide readily chemisorbs on most metal surfaces to give surface-bound oxygen and carbon atoms, which under CVD conditions become incorporated into the growing film.…”