Magneto-History Effect in the $Tb_{x}Gd_{1-x}Ni_3$ Compounds

The compounds $Tb_{x}Gd_{1-x}Ni_3$ with a $PuNi_3$-type structure have been obtained. The magnetic properties have been investigated by using SQUID magnetometer (Quantum Design MPMS, temperature from 1.9 K to 300 K and magnetic field up to 7 T). The partial replacement of Gd by Tb atoms is reflected in a decrease of the ordering temperature from 115 K (x = 0.0) to 81 K (x=1.0) as well as the increase of the saturation magnetic moment $M_{S}$ from 6.93 $μ_{B}$/f.u. (x=0.0) to 7.14 $μ_{B}$/f.u. (x=1.0). A large difference of M(T) curves has been noticed between the so-called field cooling-zero field cooling magnetization. The thermomagnetic curves are sensitive to the applied magnetic field and their origin can be understood as the domain-wall pinning effect and as the temperature dependence of coercivity.