Electronic properties, superconductivity and stability of the ordered alloys of the Ti-Rh, Zr-Rh and Hf-Rh isoelectronic systems

Structural stability of some CsCl structure HfTM (TM=Co, Rh, Ru, Fe) compounds

“…The result tells us that the gap opening is more closely related to the mean number of all valence electrons in the system than only to the d-ones, as suggested in Ref. [20]. However, the position of the Fermi level is strongly influenced by an average number of d-electrons in the system.…”

“…Generally speaking, this should provide better stability of HfFe and HfRu compared to HfCo and HfRh, which is expressed neither in the calculated enthalpies and cohesive energies, nor observed experimentally (Table 2). However, there are some indications for HfRh (as well as for isoelectronic TiRh and ZrRh) lattice distortion at low temperatures [20] which returns the E F inside the gap, and one should allow such possibility for the HfCo too. The results of calculations presented in Fig.…”

Electronic Structure of Ordered and Disordered HfRh Alloys

“…The experimental data [4] indicate that T, is less than 1.4 K, hence we can conclude that the lower value of 1 is more realistic in the HfRh, phase.…”

“…A knowledge of the electronic structures of alloys is important for the estimation of their phase stabilities [l] and their specific properties, e.g. superconductivity [2], internal pressure effects [3], or the specific heat coefficients [4]. The aim of this paper is an interpretation of these properties on the basis of the electronic structure calculations performed for the Hf-Rh ordered and disordered alloys.…”

“…The Hf-Rh compounds are paramagnetic in the whole region of concentration. The formation of the ordered structure is mainly due to the large valence differences between Rh and Hf atoms [4]. The low value of the y coefficient in the electronic specific heat for the HfRh ordered alloy indicates the location of the Fermi level in the valley between two peaks in the CsCl or CuAu type structure [l].…”