Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2611.00167

Y2CdX4 (X = S, Se, Te) Semiconductors: A First-Principles Study of Structural, Electronic, Optical, and Energy-Related Properties

Faiq Umar·Sikander Azam
View original source ↗Read source document ↗Export metadata ↓

Abstract

We present a comprehensive density functional theory (DFT) investigation of the structural, mechanical, electronic, optical, thermoelectric, and bonding properties of Y2CdX4 (X = S, Se, Te) compounds for potential optoelectronic and energy-conversion applications. Structural optimization reveals a systematic expansion of the equilibrium lattice parameters from S to Te. The calculated bulk moduli decrease from 83 GPa for Y2CdS4 to 68 GPa for Y2CdSe4 and 54 GPa for Y2CdTe4, indicating progressive lattice softening. Electronic band-structure calculations predict indirect band gaps of 2.42, 2.08, and 1.71 eV for Y2CdS4, Y2CdSe4, and Y2CdTe4, respectively, with further narrowing upon inclusion of spin-orbit coupling. The calculated dielectric functions, refractive indices, absorption coefficients, reflectivity, optical conductivities, and electron energy-loss spectra reveal systematic changes in optical response across the chalcogen series. The absorption onset shifts toward lower photon energies, from approximately 2.4 eV in Y2CdS4 to 1.7 eV in Y2CdTe4. Thermoelectric calculations indicate promising Seebeck coefficients and power factors, with Y2CdSe4 exhibiting a favorable balance of transport properties. Charge-density distributions, electron localization functions, and Bader charge analyses suggest increasing covalent bonding contributions from sulfide to telluride. These findings highlight the potential of Y2CdX4 compounds for tunable optoelectronic and energy-conversion applications.

Explore related subjects

cond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Faiq Umar, Sikander Azam. 2026-10-30. Y2CdX4 (X = S, Se, Te) Semiconductors: A First-Principles Study of Structural, Electronic, Optical, and Energy-Related Properties. https://arxiv.org/abs/2611.00167

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Impact of electron--spin coupling on exchange coupling parameters: a nonperturbative approach

Exchange coupling parameters $J_{ij}$ in the Heisenberg model are crucial for describing magnetic behavior at the atomic level. In magnetic materials, spin fluctuations can be accompanied by a self-consistent electronic response, i.e., electron--spin coupling in the sense of electronic feedback to finite spin rotations. However, the quantitative importance of this coupling in extracting reliable $J_{ij}$ has not been fully clarified. Here, using fully self-consistent, nonperturbative evaluations, we show that finite-angle spin rotations induce such electronic feedback and quantify how strongly it renormalizes the extracted $J_{ij}$. We examine systems of both fundamental and practical interest, including perovskite SrMnO$_3$, Nd-based permanent-magnet compounds (Nd$_2$Fe$_{14}$B and Nd$_2$Co$_{14}$B), and elemental 3$d$ transition metals. The nonperturbative approach yields exchange couplings that remain consistent over a wide range of rotation angles. Moreover, when the sampled configurations represent the magnetic disorder near the transition, spin models parameterized in this way give reasonable agreement with experimental magnetic phase-transition temperatures. Overall, our results demonstrate the quantitative impact of electron--spin coupling on the exchange coupling parameters $J_{ij}$ and provide a nonperturbative route to effective $J_{ij}$ for a specified regime of magnetic disorder.

cond-mat.mtrl-sci↗
arXiv2026

Benchmarking and advancing machine-learning interatomic potentials for 3C-SiC across equilibrium and extreme conditions

Several machine-learning interatomic potentials (MLIPs) have been developed for cubic silicon carbide (3C-SiC). Here, we benchmark seven existing MLIPs against a common set of structural, thermal, defect, radiation-damage, disordered-phase, and computational-performance tests. We also introduce two complementary MLIPs trained on DFT-labeled crystalline, liquid, amorphous, and defective configurations. TGAP, a Gaussian approximation potential based on the \verb|soap_turbo| descriptor, provides consistently high accuracy across the sampled configurational space. MTP, a custom moment tensor potential, retains good accuracy across these regimes while offering substantially lower computational cost, GPU acceleration, and access to multi-million-atom simulations. As an application-level test, both potentials remain stable in displacement cascades spanning short-range repulsion, transient disorder, and recrystallization. Overall, MTP emerges as a particularly strong accuracy--cost compromise for large-scale and strongly non-equilibrium simulations of 3C-SiC.

cond-mat.mtrl-sci↗
arXiv2026

Loss of altermagnetic order and smooth restoration of Kramers' spin degeneracy with increasing temperature in CrSb and MnTe

We describe how thermally induced spin fluctuations modify the electronic structures of two prototypical altermagnets, CrSb and MnTe, via application of the disordered local moment picture. For both materials, our self-consistent, ab initio calculations demonstrate that local magnetic moments persist on Cr and Mn atoms in their paramagnetic states, necessitating a spin-polarised description of the electronic structure even above the Néel temperature, $T_\mathrm{N}$. Moreover, Kramers' spin degeneracy, which is broken for both materials in their altermagnetic ground states, is shown to be smoothly restored - on the average - as the local moments thermally disorder. In metallic CrSb, this occurs at temperatures well below $T_\mathrm{N}$ and the signature effects of its altermagnetism are lost as the magnetic disorder induces heavy smearing of strongly dispersive electronic states around the Fermi energy. By contrast, in semiconducting MnTe, with its band gap largely unaffected by magnetic disorder, the spin degeneracy only returns at temperatures close to and above $T_\mathrm{N}$. We quantify the temperature dependence of the altermagnetic order parameter and the underlying electronic structures of both materials, with implications for their spin transport and spectroscopic properties.

cond-mat.mtrl-sci↗