Lutetium ''paradox'' in the series of intermetallic compounds RCo2 (R is a heavy rare earth or yttrium)

Magnetic properties of R(Co1-xAlx)2 (where R is a heavy rare earth Gd, Tb, Dy, Ho, Er, Tm, Lu or Y) systems are compared. An unusual magnetic behavior of Lu(Co1-xAlx)2 system is noted which cannot be described in the supposition of the same band structure as those of other R(Co1-xAlx)2 systems of this series for the Al concentrations x > 0.1. Experimental data on the concentration dependence of Tc for Tm1-tLut(Co0.88Al0.12)2 confirm this conclusion. (orig.)