Synthesis and magnetic characterization of TmCo2B2C
  A new quaternary intermetallic borocarbide TmCo2B2C has been synthesized via a rapid-quench of an arc-melted ingot. Elemental and powder-diffraction analyses established its correct stoichiometry and single-phase character. The crystal structure is isomorphous to that of TmNi2B2C(I4/mmm) and is stable over the studied temperature range. Above 7 K, the paramagnetic state follows the modified Curie-Weiss behavior (X=C/(T-theta)+X0 wherein X0=0.008(1) emu/mole and the temperature-dependent term reflecting the paramagnetism of the Tm subsystem: ueff=7.6(2) uB [in agreement with the expected value for a free Tm3+ ion] and theta = -4.5(3) K. Long range ferromagnetic order of the Tm sublattice is observed to develop around ~1 K. No superconductivity is detected in TmCo2B2C down to 20 mK, a feature which is consistent with the general trend in the RCo2B2C series. Finally, the influence of the rapid-quench process on the magnetism (and superconductivity) of TmNi2B2C will be discussed and compared to that of TmCo2B2C. 
M. ElMassalami, R. E. Rapp, F. A. B. Chaves and R. Moreno, H. Takeya,   B. Ouladdiaf, J. W. Lynn, Q. Huang, R. S. Freitas an...