Table 1 shows the compositions prepared and their
thermal history. In a first step, NixTi13xB2xO2 (B=Sb,
Nb; 04x41/3) samples were prepared (thermal history
A). From the characterization of these samples, x=0.10
was chosen to compare results of rutile or cassiterite
host matrix. Thus, samples of Ni0.1A0.7B0.2O2 (A=Ti,
Sn; B=Sb, Nb) were also prepared (thermal history B).