Investigation of the Effect of NiO Nanoparticles on the Transport Properties of Zr<SUB>0.5</SUB>Hf<SUB>0.5</SUB>Ni<SUB>1–<I>x</I></SUB>Pd<SUB><I>x</I></SUB>Sn<SUB>0.99</SUB>Sb<SUB>0.01</SUB> (<I>x</I> = 0 and 0.2)