Magnetic phase diagram of YbCo2Si2 derived from magnetization   measurements
  We report on high-resolution dc-magnetization (M) measurements on a high-quality single crystal of YbCo2Si2. M was measured down to 0.05K and in fields up to 4T, with the magnetic field oriented along the crystallographic directions [100], [110] and [001] of the tetragonal structure. 
L. Pedrero, C. Klingner, C. Krellner, M. Brando, C. Geibel and F.   Steglich
cond-mat.str-el