INFLUENCE OF THE D-ELECTRON CONCENTRATION ON THE ITINERANT ELECTRON METAMAGNETISM AND FERROMAGNETISM IN Y(CO1-XALX)2 LU(CO1-XALX)2 SYSTEMS - STUDY OF COMPOUNDS WITH UNVARIABLE CRYSTAL CELL PARAMETER

Magnetic properties of the (Y(1-t)Lu(t))(Co(1-x)Al(x))2 system in which the crystal cell parameter was kept constant by partial substitution of lutetium for yttrium have been investigated in dependence of the aluminum concentration within the 0 less-than-or-equal-to x less-than-or-equal-to 0.22 interval. The concentration dependence of the critical field of the metamagnetic transition and the character of arising of ferromagnetic order are analyzed. The magnetic (x-T) phase diagram of (Y(1-t)Lu(t))(Co(1-x)Al(x))2 system is obtained. The comparison with analogous results for Y(Co(1-x)Al(x))2 and Lu(Co(1-x)Al(x))2 systems, in which the itinerant electron metamagnetism have been observed earlier, leads to the conclusion that the main factor acting on the transformation of magnetic properties of YCo2 and LuCo2 when aluminum replaces cobalt is the change of d-electron concentration but not the increase of the crystal cell parameter.