Magnetic and Structural Properties of GdFe_1–x Ti _x Si

Magnetocaloric effect and magnetic ordering in GdFe1−xTxSi, T = Cr, V, Ni

“…5 and Table 2. For comparison, the previously obtained T C ( x ) values of GdFe 1− x Ti x Si 15,16 are also shown in Fig. 5.…”

“…The MCE of the GdFe 1− x T x Si systems decreases exponentially with a change in composition. One can see that the −Δ S M ( T C ) values decrease in the case of V and Ti 15 faster than for Cr or Ni ( x < 0.3). Apparently, the compounds with Cr or Ni are more homogeneous than with V or Ti; therefore, the MCE is higher for the former.…”

“…It can be seen that the lattice parameter c sharply increases, while the lattice parameter a slightly decreases with an increase in the content of T = Cr, V, and Ti. 15,16 On the contrary, for the GdFe 1− x Ni x Si system, the parameter c noticeably decreases and a slightly increases up to x = 0.3 and then shows no further change. The parameter c reaches its maximum value for the compositions x = 0.6 and 0.3 in the case of the GdFe 1− x Cr x Si and GdFe 1− x V x Si systems, respectively, and then decreases.…”

“…There is an understandable regularity: the smaller the atomic radius of the 3d metal, the greater its solubility in the substitutional compound (Table 1 and ref. 15, 16) and the more homogeneous substitutional compound.…”

“…Comparing the T C values for the GdFe 1Àx T x Si systems with T = Cr, V, Ti, and Ni series with the lattice parameter c, we can come to a conclusion that these temperatures vary similarly to the c lattice constant as well as with the distance between the gadolinium layers. That is, in all the GdFe 1Àx T x Si, T = Cr, V, Ti, Ni, systems the Gd-Gd exchange interaction paradoxically increases\decreases as the Gd-Gd 15,16 interatomic distance increases\decreases, although it is natural to expect the opposite dependence. Since the 3d ions in GdFe 1Àx T x Si are non-magnetic, the T C of the compounds is stipulated by an indirect Gd-Gd exchange interaction, which is realized through polarization of conduction electrons.…”