FERROMAGNETISM OF THE CHIMNEY-LADDER COMPOUND CR11GE19

Using a non-self-consistent tight-binding-LMTO method, we have obtaine d the densities of states for Cr11Ge19 and Mn11Si19. The calculations show a deep minimum in the density of states at an energy correspondin g to a valence electron concentration of 14 per Cr (Mn) atom. For Cr11 Ge19, the Fermi level lies in a high density of states region, suggest ing magnetism. Experimentally we have found that this compound is inde ed ferromagnetic below 100 K. (C) 1997 Elsevier Science S.A.