arXiv subjects

C. F. Schuch

Publications and source records attributed to C. F. Schuch.

3 recordsLinked to original sources

arXiv2026

Electronic properties governing the phase stability and elastic anisotropy of C14 and C15 Cr-Hf-Nb Laves phases

This study utilizes Density Functional Theory (DFT) to investigate the thermodynamic stability, elastic anisotropy, and electronic properties of C14 and C15 Laves phases within the Cr--Hf--Nb system. Both formation enthalpies and comprehensive elastic property analyses confirm the energetic and mechanical stability of the C14 (HfNb$_2$, HfCr$_2$, NbCr$_2$) and C15 (HfCr$_2$, NbCr$_2$) phases. Furthermore, the evaluation of elastic anisotropy reveals a descending order of HfCr$_2$ > NbCr$_2$ > HfNb$_2$ for the C14 phase, contrasting with NbCr$_2$ > HfNb$_2$ > HfCr$_2$ for the C15 phase. Finally, electronic structure and COHP analyses indicate that strong anti-bonding behavior near the Fermi level within the XM$_2$ M--M bonds acts as a primary destabilization mechanism for both of these Laves phases.

cond-mat.mtrl-sci↗

arXiv2026

Superconductivity and electronic structure evolution in the enforced semimetal Fe-doped ZrTe$_2$

ZrTe$_2$ is an outstanding layered semimetal due to the topologically nontrivial electronic structure. In this work, we present an investigation of the electronic evolution of ZrTe$_2$ in the presence of Fe intercalation, namely Fe$_{x}$ZrTe$_2$ ($x= 0 - 0.25$), scrutinized by both experimental measurements and \textit{ab} initio calculations. While the first reveals a superconducting state with a maximum critical temperature $T_c = 2.74$ K ($x=$ 0.03), the latter indicates that the topological features of the pristine ZrTe$_2$ is sensitive to the distance between Te atoms and Zr layers. Also, the intercalation of Fe does not modify the non-trivial electronic band structure unlike the band crossings are now shifted slightly below $E_{F}$. In particular, a van Hove singularity near the Fermi level for a Fe content of $x=0.125$ is observed in the density of states, indicating that the superconducting order may be associated with features of the unfolded band structure and the concomitant enhancement of the density of states at $E_F$. Finally, our results reveal that the new compound with inclusion of Fe intercalation preserves the enforced semimetal classification.

cond-mat.supr-con↗

arXiv2026

Substitution modulated transition from semimetal to superconductor in ZrTe$_{2-x}$Se$_x$ with coexistence of nontrivial electronic topology

This study explores the emergence of superconductivity in high-quality ZrTe$_{2-x}$Se$_x$ crystals, grown via the isothermal chemical vapor transport (ICVT) technique. Resistive, structural, and thermal measurements reveal that substituting Te with Se in the ZrTe$_2$ matrix induces a superconducting state at low temperatures. The critical temperature ($T_c$) exhibits a clear dependence on the selenium concentration, peaking at $x=0.15$ with a $T_c$ of $4.8$ K. Calorimetric data indicates that even a low Se substitution range is capable of modifying both the electronic contribution and the vibrational modes of the crystal lattice. Combined with ab initio calculations and Wannier Hamiltonian interpolation between ZrTe$_2$/ZrSe$_2$, we established an extensive phase diagram mapping the transition from charge density wave (CDW) to the state with coexistence between the Dirac semimetal and superconductivity (SC), up to the semiconductor phase. This coexistence suggests that ZrTe$_{1.85}$Se$_{0.15}$ could be a candidate platform for topological superconductivity, as it hosts a nontrivial $\mathbb Z_2$ invariant, with nonvanishing surface states in its $(001)$ planes.

cond-mat.supr-con↗