X-ray photoemission and magnetometric studies of valence changes in Ce(Cu1−xNix)4Ga

Thermoelectric Power in Ce Systems with Unstable Valence

“…On the right-hand axis of Figure 6, the temperature dependence of the f occupancy is plotted in a similar manner as for the previous exemplary compounds. The value at 300 K is equal to 0.75, which is in perfect agreement with the value nf = 0.76, which we have obtained by the analysis of the RT Ce 3d XPS spectrum [21].…”

“…The discussed exemplary compositions were studied and described in our previous papers [16][17][18][19][20][21], where the details concerning the synthesis of the polycrystalline samples by arc-melting and the measurements of the thermoelectric power can be found. The main point of the current study is to show how the novel model of S(T) works for these exemplary compounds.…”

Specific heat of the Ce(Cu1−xNix)4Ga alloys

“…Our previous studies of the thermopower have revealed the presence of a large positive peak at 28 K that has been ascribed to the crystal electric field (CEF) effect leading to an average split of the ground state of the order of D ¼ 64 K [8]. The gradual substitution of Cu with Ni reveals a fluctuating valence (FV) in the final composition CeNi 4 Ga, which has been shown in our X-ray photoemission spectroscopy (XPS) measurements on the Ce(Cu 1Àx Ni x ) 4 Ga alloys by observation of the evolution of the Ce 3d states and the valence band [9]. The measurements of the magnetic properties and the calculation of the electronic structure have also been performed for the parent compound CeNi 4 Ga [10,11].…”

“…The CEF splitting of the energy levels obtained in this work conforms to the reported values based on the inelastic neutron scattering study. Figure 5 Electronic specific heat coefficient at 2 K and the hybridization parameter between the 4f states and conduction electrons [9] as a function of the Ni content.…”