We studied the structural and magnetic properties of ${\mathrm{Fe}}_{0.8}{\mathrm{C}}_{0.2}$ thin films deposited by co-sputtering of Fe and C targets in a direct current magnetron sputtering (dcMS) process at a substrate temperature ($T_s$) of 300, 523, and 773 K. The structure and morphology were measured using x-ray diffraction (XRD), x-ray absorption near-edge spectroscopy (XANES) at Fe $L$ and C $K$ edges and atomic/magnetic force microscopy (AFM, MFM). An ultrathin (3-nm) ${}^{57}\mathrm{Fe}_{0.8}\mathrm{C}{}_{0.2}$ layer, placed between relatively thick ${\mathrm{Fe}}_{0.8}{\mathrm{C}}_{0.2}$ layers was used to estimate Fe self-diffusion taking place during growth at different $T_s$ using depth profiling measurements. Such ${}^{57}\mathrm{Fe}_{0.8}\mathrm{C}{}_{0.2}$ layer was also used for ${}^{57}\mathrm{Fe}$ conversion electron Mössbauer spectroscopy (CEMS) and nuclear resonance scattering (NRS) measurements, yielding the magnetic structure of this ultrathin layer. We found from XRD measurements that the structure formed at low $T_s$ (300 K) is analogous to Fe-based amorphous alloy and at high $T_s$ (773 K), predominantly a ${\mathrm{Fe}}_3\mathrm{C}$ phase has been formed. Interestingly, at an intermediate $T_s$ (523 K), a clear presence of ${\mathrm{Fe}}_4\mathrm{C}$ (along with ${\mathrm{Fe}}_3\mathrm{C}$ and Fe) can be seen from the NRS spectra. The microstructure obtained from AFM images was found to be in agreement with XRD results. MFM results also agree well with NRS as the presence of multi-magnetic components can be clearly seen in the sample grown at $T_s$ = 523 K. The information about the hybridization between Fe and C, obtained from Fe $L$- and C $K$-edge XANES also supports the results obtained from other measurements. In essence, from this work, a possibility for experimental realization of ${\mathrm{Fe}}_4\mathrm{C}$ has been demonstrated. It can be anticipated that by further fine-tuning of the deposition conditions, even single-phase ${\mathrm{Fe}}_4\mathrm{C}$ can be realized which hitherto remains an experimental challenge.

The recent discovery of quaternary MAX phases with chemical in-plane order allowed the addition of nontraditional MAX phase elements, such as rare-earth elements. In the present study, first-principles calculations are performed to investigate the electronic structure, elastic and hardness response, and bonding strengths of the novel $\mathrm{RE}\text{−}i\text{−}\mathrm{MAX}$ phases with the formula ${\left({\text{Mo}}_{2/3}{\text{RE}}_{1/3}\right)}_2\text{AlC}$. The Voigt-Reuss-Hill bulk, shear, and Young's moduli are compared along the series of RE = Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu, and the global trend is found to depend on the unit cell volume. Nanoindentation experiments on Ho-based single crystals result in moduli that are within 10% of predicted values and a hardness of $\sim 10$ GPa. The computation of the projected density of states, projected crystal orbital Hamilton population, and integrated projected crystal orbital Hamilton population, reveals that the bonding of Mo and RE atoms with the Al atoms are weaker than those with the C atoms, suggesting the exfoliation of $\mathrm{RE}\text{−}i\text{−}\mathrm{MAX}$ into two-dimensional $\mathrm{RE}\text{−}i$-MXenes to be feasible. Such a possibility to form two-dimensional crystals is further confirmed by the computation of the exfoliation energies, which demonstrates the process to be easier as the RE atomic mass decreases.

Configurational disorder can have a dominating role in the formation of macroscopic functional responses in strongly correlated materials. Here, we use entropy-stabilization synthesis to create single-crystal epitaxial $\mathrm{AB}{\mathrm{O}}_3$ perovskite thin films with equal atomic concentration of 3d transition-metal cations on the B-site sublattice. X-ray diffraction, atomic force microscopy, and scanning transmission electron microscopy of $\mathrm{La}\left(\mathrm{C}{\mathrm{r}}_{0.2}\mathrm{M}{\mathrm{n}}_{0.2}\mathrm{F}{\mathrm{e}}_{0.2}\mathrm{C}{\mathrm{o}}_{0.2}\mathrm{N}{\mathrm{i}}_{0.2}\right){\mathrm{O}}_3$ (L5BO) films demonstrate excellent crystallinity, smooth film surfaces, and uniform mixing of the 3d transition-metal cations throughout the B-site sublattice. The magnetic properties are strongly dependent on substrate-induced lattice anisotropy and suggest the presence of long-range magnetic order in these exceptionally disordered materials. The ability to populate multiple elements onto a single sublattice in complex crystal structures opens new possibilities to design functionality in correlated systems and enable novel fundamental studies seeking to understand how diverse local bonding environments can work to generate macroscopic responses, such as those driven by electron-phonon channels and complex exchange interaction pathways.

To study how nitrogen contributes to perpendicular magnetocrystalline anisotropy (PMA) in the ferrimagnetic antiperovskite $\mathrm{M}{\mathrm{n}}_4\mathrm{N}$, we examined both the fabrication of epitaxial $\mathrm{M}{\mathrm{n}}_4\mathrm{N}$ films with various nitrogen contents and first-principles density-functional calculations. Saturation magnetization $\left(M_{\mathrm{s}}\right)$ peaks of 110 mT and uniaxial PMA energy densities $\left(K_{\mathrm{u}}\right)$ of $0.1\mathrm{MJ}/{\mathrm{m}}^3$ were obtained for a ${\mathrm{N}}_2$ gas flow ratio ($Q$) of ∼10% during sputtering deposition, suggesting nearly single-phase crystalline $\varepsilon \text{−}\mathrm{M}{\mathrm{n}}_4\mathrm{N}$. Segregation of α-Mn and nitrogen-deficient $\mathrm{M}{\mathrm{n}}_4\mathrm{N}$ grains were observed for $Q\approx 6\%$, and were responsible for a decrease in the $M_{\mathrm{s}}$ and $K_{\mathrm{u}}$. The first-principles calculations revealed that the magnetic structure of $\mathrm{M}{\mathrm{n}}_4\mathrm{N}$ showing PMA was “type B,” having a collinear structure, whose magnetic moments couple parallel within the $c$ plane and alternating along the $c$ direction. In addition, the $K_{\mathrm{u}}$ calculated using $\mathrm{M}{\mathrm{n}}_{32}{\mathrm{N}}_x$ supercells showed a strong dependence on nitrogen deficiency, in qualitative agreement with the experimental results. The second-order perturbation analysis of $K_{\mathrm{u}}$ with respect to the spin-orbit interaction revealed that not only spin-conserving but also spin-flip processes contribute significantly to the PMA in $\mathrm{M}{\mathrm{n}}_4\mathrm{N}$. We also found that both contributions decreased with increasing nitrogen deficiency, resulting in the reduction of $K_{\mathrm{u}}$. It was noted that the decrease in the spin-flip contribution occurred at the Mn atoms in face-centered sites. This is one of the specific PMA characteristics we found for antiperovskite-type $\mathrm{M}{\mathrm{n}}_4\mathrm{N}$.

We report the observation of superconductivity in single-crystalline ${\mathrm{CaPd}}_2{\mathrm{P}}_2$ and ${\mathrm{SrPd}}_2{\mathrm{P}}_2$ obtained from Bi-flux. Both ${\mathrm{CaPd}}_2{\mathrm{P}}_2$ and ${\mathrm{SrPd}}_2{\mathrm{P}}_2$ crystallize in the ${\mathrm{ThCr}}_2{\mathrm{Si}}_2$-type structure (space group I4/mmm) with a short P-P distance. Electrical resistivity and specific heat measurements conjointly corroborate bulk superconductivity at $T_c\sim 1.0$ K with $\mathrm{\Delta }C/\gamma T_{\mathrm{c}}=1.42$ for ${\mathrm{CaPd}}_2{\mathrm{P}}_2$, and $T_c\sim 0.7$ K with $\mathrm{\Delta }C/\gamma T_c=1.47$ for ${\mathrm{SrPd}}_2{\mathrm{P}}_2$. The electronic structure calculations and chemical bonding analysis indicate that Pd-P antibonding interactions primarily dominate around the Fermi level and play the critical role in inducing superconductivity.

High electron mobility is pivotal in engineering oxide interfaces for electronic devices. Here, interfacial structure and physical behaviors of $\gamma \text{−}{\mathrm{Al}}_2{\mathrm{O}}_3/{\mathrm{SrTiO}}_3$ spinel/perovskite heterostructure are explored to understand the microscopic origin of its extremely high electron mobility $(1.4\times {10}^5{\mathrm{cm}}^2{\mathrm{V}}^{-1}{\mathrm{s}}^{-1}$ at 2 K). Lattice mismatch at interface and intrinsic Al cation vacancies result in unexpected interfacial reconstruction and anisotropic electronic behavior. The spontaneous polarization in the $\gamma \text{−}{\mathrm{Al}}_2{\mathrm{O}}_3$ part leads to an insulator-metal transition observed experimentally, even if the thickness of $\gamma \text{−}{\mathrm{Al}}_2{\mathrm{O}}_3$ is only one unit cell, and a strong internal electric field can be as large as 142 mV/Å, roughly 1.8 times the experimentally observed value of 80.1 mV/Å in ${\mathrm{LaAlO}}_3/{\mathrm{SrTiO}}_3$. As a result, unlike only in-plane slightly occupied $\mathrm{Ti}\text{−}{d}_{xy}$ subbands in the conventional ${\mathrm{SrTiO}}_3$-based perovskite/perovskite heterostructure, all three $t_{2g}$ orbitals have charge exchange with the surfacial $\mathrm{O}\text{−}2p$ orbitals in $\gamma \text{−}{\mathrm{Al}}_2{\mathrm{O}}_3/{\mathrm{SrTiO}}_3$; especially, the preferential orbital occupation is out-of-plane $\mathrm{Ti}\text{−}{d}_{xz}/\mathrm{Ti}\text{−}{d}_{yz}$ at the interface. Nontrivial orbital occupation and complicated interfacial reconstruction result in large group velocity and a high density of states at the Fermi level and therefore serve as the origins of extremely high electron mobility and high carrier concentration. The physical mechanism revealed in our work offers insight into the creation of high-mobility nanoscale electronic devices.

We used nonequilibrium molecular dynamics simulations to study the shear deformation of metallic composites composed of alternating layers of Cu and Au. Our simulations reveal the formation of “vortices” or “swirls” if the bimaterial interfaces are atomically rough and if none of the $\left\{111\right\}$ planes that accommodate slip in fcc materials are exactly parallel to this interface. We trace the formation of these patterns back to grain rotation, induced by hindering dislocations from crossing the bimaterial interface. The instability is accompanied by shear softening of the material. These calculations shed light on recent observations of pattern formation in plastic flow, mechanical mixing of materials, and the common formation of a tribomutation layer in tribologically loaded systems.

Drift velocity saturation (at some characteristic value, $v_d^{\mathrm{sat}}$) is a critical process that limits the ultimate current-carrying capacity of semiconductors at high electric fields $(\sim {10}^4\mathrm{V}/\mathrm{cm})$ . With the recent emergence of two-dimensional (2D) semiconductors, there is a need to understand the manner in which velocity saturation is impacted when materials are thinned to the monolayer scale. Efforts to determine $v_d^{\mathrm{sat}}$ are typically hampered, however, by self-heating effects that arise from undesirable energy loss from the active 2D layer to the dielectric substrate that supports it. In this work, we explore this problem for an important 2D semiconductor, namely monolayer molybdenum disulfide ($\mathrm{Mo}{\mathrm{S}}_2$). By applying a strategy of rapid (nanosecond duration), single-shot, pulsing, we are able to probe the true hot-carrier dynamics in this material, free of the influence of self-heating of its $\mathrm{Si}{\mathrm{O}}_2$ substrate. Our approach allows us to realize high current densities $(\sim \mathrm{mA}/\mu \mathrm{m})$ in the $\mathrm{Mo}{\mathrm{S}}_2$ layers, representing a significant enhancement over prior studies. We similarly infer values for the saturated drift velocity $(v_d^{sat}\sim 5-7\times {10}^6\mathrm{cm}{\mathrm{s}}^{-1})$ that are higher than those reported in earlier works, in which the influence of self-heating (and carrier injection into oxide traps) could not be excluded. In fact, our estimates for $v_d^{\mathrm{sat}}$ are somewhat close to the ideal velocity expected for normal (parabolic) semiconductors. Since a proper knowledge of this parameter is essential to the design of active electronic and optoelectronic devices, the insight into velocity saturation provided here should provide useful guidance for such efforts.

We combined experimental investigations and theoretical calculations to unveil an abnormal magnetic behavior caused by addition of the nonmagnetic element Cu in face-centered-cubic FeNiCoMn-based high-entropy alloys (HEAs). Upon Cu addition, the probed HEAs show an increase of both Curie temperature and saturation magnetization in as-cast and homogenized states. Specifically, the saturation magnetization of the as-cast HEAs at room temperature increases by 77% and 177% at a Cu content of 11 and 20 at. %, respectively, compared to the as-cast equiatomic FeNiCoMn HEA without Cu. The increase in saturation magnetization of the as-cast HEAs is associated with the formation of an Fe-Co rich phase in the dendritic regions. For the homogenized HEAs, the magnetic state at room temperature transforms from paramagnetism to ferromagnetism after 20 at. % Cu addition. The increase of the saturation magnetization and Curie temperature cannot be adequately explained by the formation of Cu enriched zones according to atom probe tomography analysis. Ab initio calculations suggest Cu plays a pivotal role in the stabilization of a ferromagnetic ordering of Fe, and reveal an increase of the Curie temperature caused by Cu addition which agrees well with the experimental results. The underlying mechanism behind this phenomenon lies in a combined change in unit-cell volume and chemical composition and the related energetic stabilization of the magnetic ordering upon Cu alloying as revealed by theoretical calculations. Thus, the work unveils the mechanisms responsible for the Cu effect on the magnetic properties of FeNiCoMn HEAs, and suggests that nonmagnetic elements are also crucial to tune and improve magnetic properties of HEAs.

The geometrical control of oxygen vacancy channels (OVCs) and their orientation in brownmillerite (BM) structures provide a platform for tailoring the physical properties. The growth with different OVCs orientation implies a huge change in lattices that limit the epitaxial growth. Here we achieve epitaxial growth of $\mathrm{SrFe}{\mathrm{O}}_{2.5}$ ($\mathrm{SF}{\mathrm{O}}_{2.5}$) films with horizontal or vertical OVCs, irrespective of the substrates of (001) $\mathrm{SrTi}{\mathrm{O}}_3, \mathrm{L}{\mathrm{a}}_{0.3}\mathrm{S}{\mathrm{r}}_{0.7}\mathrm{A}{\mathrm{l}}_{0.65}\mathrm{T}{\mathrm{a}}_{0.35}{\mathrm{O}}_3$, and $\mathrm{LaAl}{\mathrm{O}}_3$. For vertical OVCs, the substrate mismatch is overcome by the topotactic phase transition of $\mathrm{SrFe}{\mathrm{O}}_{3-\delta }$ at the film/substrate interface, whereas the epitaxy with horizontal OVCs is achieved simply by low oxygen pressure growth. It is found that the antiferromagnetic axes of the prepared films are intimately associated with crystal orientation that can be changed by controlling the OVCs direction, while the (ferro)magnetic anisotropy is also observed accompanied by more robust magnetization in the direction perpendicular to the OVCs, where the magnetization arises from the canted moments. Horizontal and vertical OVCs scenarios are also achieved in $\mathrm{L}{\mathrm{a}}_{0.7}\mathrm{S}{\mathrm{r}}_{0.3}\mathrm{Mn}{\mathrm{O}}_3/\mathrm{SF}{\mathrm{O}}_{2.5}$ bilayer samples in a controllable manner, which show ferromagnetic coupling and decoupling, respectively. Our findings not only add a different dimension for the epitaxial growth of films on a wide range of substrates but also demonstrates the use of OVCs for tailoring physical properties of oxides.

In this paper, we present a comprehensive investigation of the epitaxial growth of ${\mathrm{Ba}}_2{\mathrm{SiO}}_4$ on Si(001), a system in which neither crystal symmetry nor lattice constants match in a simple manner. In addition, it has the potential to become the first crystalline high-$k$ gate dielectric. We combined x-ray photoelectron spectroscopy, low-energy electron diffraction, and aberration-corrected scanning transmission electron microscopy (STEM) in order to optimize the epitaxial growth by molecular beam epitaxy. Our focus was on the formation of a high quality crystalline interface. The films were grown by a co-deposition method that requires no diffusion of Si from the substrate. An annealing temperature of $400{}^{\circ }\mathrm{C}$ turned out to be sufficient to form chemically homogeneous films. However, crystalline films require an annealing step to $670\text{–}690{}^{\circ }\mathrm{C}$ for the formation of the epitaxial interface necessary for breaking Si-O bonds. STEM confirms that the interface is atomically sharp and that a single layer of the silicate is changed to a ($2\times 3$) structure at the interface from the ($2\times 1.5$) bulk structure. Based on our experimental results, we propose a geometrical model for the epitaxial interface. The growth of films with an understoichiometric Si flux leads to the formation of a near-surface Ba silicide that does not restrict the epitaxial silicate growth.

The $\alpha /\beta$ interface in Ti-6Al-2Sn-4Zr-6Mo (Ti-6246) was investigated via center of symmetry analysis, both as-grown and after 10% cold work. Semicoherent interface steps are observed at a spacing of $4.5\pm 1.13$ atoms in the as-grown condition, in good agreement with theory. Lattice accommodation is observed, with elongation along $\mathrm{[}\overline{1}2\overline{1}{0]}_{\alpha }$ and contraction along ${\left[10\overline{1}0\right]}_{\alpha }$. Deformed $\alpha$ exhibited larger, less coherent steps with slip bands lying in ${\left\{110\right\}}_{\beta }$. This indicates dislocation pile-up at the grain boundary, a precursor to globularization during heat treatment. Atom probe tomography measurements of secondary $\alpha$ plates in the fully heat-treated condition showed a Zr excess at the interface, which was localized into regular structures indicative of Zr association with interface defects, such as dislocations. Such chemo-mechanical stabilization of the interface defects would both inhibit plate growth during elevated temperature service and the interaction of interface defects with gliding dislocations during deformation.

Controlling strain in hetero-epitaxial material systems can be used to optimize properties and functionalities for specific applications. For this purpose, a lattice mismatch between substrate and epitaxial layer is typically exploited. Beyond that, vicinal substrate surfaces can be used to enhance strain-induced effects. In both cases, a profound understanding of the impact of strain on the growth mode and the resulting structure and morphology of the epitaxial layer is of great importance in order to achieve the desired modifications. In this study, the impact of vicinal substrate surfaces on the phase, structure as well as on surface pattern formation in epitaxial phase-change material thin films is investigated. It is found that in the case of the prototypical phase-change material $\mathrm{G}{\mathrm{e}}_2\mathrm{S}{\mathrm{b}}_2\mathrm{T}{\mathrm{e}}_5$, the change from nominally flat Si(111) substrates to substrates with a miscut of 6° and terrace widths lying between 2 and 5 nm enhances compressive strain and a transition from 2D island nucleation to step-flow growth. This results in a different $\mathrm{G}{\mathrm{e}}_2\mathrm{S}{\mathrm{b}}_2\mathrm{T}{\mathrm{e}}_5$ phase evolution (change from metastable to stable phase) and surface nanostructuring by regularly arranged terraces that resemble the surface topography of the substrates. This work therefore provides deeper insights into different regimes of growth of epitaxial $\mathrm{G}{\mathrm{e}}_2\mathrm{S}{\mathrm{b}}_2\mathrm{T}{\mathrm{e}}_5$ thin films and paves the way for strain-induced modification possibilities such as band-gap tuning, optimization of the switching energy or the figure of merit.

The band gaps and structural properties of ${\mathrm{InAs}}_{1-x}{\mathrm{Sb}}_x$ alloys are investigated using both the modified Becke-Johnson exchange potential and hybrid functional calculations. A good agreement between the two approaches is observed for the alloys. The estimated value of $0.85\mathrm{eV}$ for the bowing parameter enables the use of $\mathrm{InAsSb}$ in long wavelength infrared (LWIR) applications. Furthermore, a lower limit of $0.29\mathrm{eV}$ for the bowing parameter is obtained for the structures yielding the largest band gaps, demonstrating the strong nonlinearity of the band gap versus the composition for this system.

We present molecular dynamics simulations of atomic mixing over a $\mathrm{Si}/{\mathrm{SiO}}_2$ heterostructure interface, induced by focused ${\mathrm{Ne}}^{+}$ and broad ${\mathrm{Si}}^{+}$ ion-beam irradiations, using a speed-up scheme that significantly reduces the relaxation time of the cascading recoils. To assess the qualitative reliance of the chosen method, two different potential models for Si–O, Si–Si, and O–O interactions were used: the Stillinger-Weber–like Watanabe-Samela potential and the Tersoff-like Munetoh potential. Furthermore, the molecular dynamics simulations were assessed by simulating a similar case, at a total fluence of $1\times {10}^{15}{\mathrm{cm}}^{-2}$, with the binary collision approximation. The same general atomic density profile distributions were achieved with both models; however, the binary collision approach showed shallower penetration of Si into the ${\mathrm{SiO}}_2$ layer. Coordination analysis of the molecular dynamics results provides strong evidence that ion mixing at high fluences leads to coordination defects, which will affect the electronic properties of the structures unless removed with annealing.

Ultrathin oxide films have attracted considerable attention due to the potential for the integration of next-generation devices. However, the transport behaviors of the ultrathin oxide films are yet to be explored due to the high resistance caused by the strong influence of the interface and substrates. In this paper, an attempt is made to engineer the transport behaviors in ultrathin oxides. To exclude the high-resistance issue, conductive $\mathrm{SrRu}{\mathrm{O}}_3$ with thickness down to two unit cells is embedded in insulating $\mathrm{SrTi}{\mathrm{O}}_3$ in the form of superlattices. With precise control of the thickness in each layer, the transport behaviors, as well as the anomalous Hall effects, in $\mathrm{SrRu}{\mathrm{O}}_3$ can be systematically manipulated. The analysis indicates that the diversity of the anomalous Hall effects is attributed to the change of Berry curvatures. The results give a pathway to the control of physical properties in ultrathin oxide systems by thickness engineering.

We analyze the shape and position of heteroepitaxial InAs islands on the top face of cylindrical GaAs(111)A nanopillars experimentally and theoretically. Catalyst-free molecular beam epitaxial growth of InAs at low temperatures on GaAs nanopillars results in InAs islands with diameters <30 nm exhibiting predominantly rounded triangular in-plane shapes. The islands show a tendency to grow at positions displaced from the center towards the pillar edge. Atomistic molecular statics simulations evidence that triangular-prismatic islands centered to the pillar axis with diameters smaller than that of the nanopillars are energetically favored. Moreover, we reveal the existence of minimum-energy states for off-axis island positions, in agreement with the experiment. These findings are interpreted by evaluating the spatial strain distributions and the number of broken bonds of surface atoms as a measure for the surface energy. The preferred off-axis island positions can be understood in terms of an increased compliancy of the GaAs nanopillar beneath the island because of the vicinity of free surfaces, leading to a reduction of strain energy. The influence of surface steps on the energy of the system is addressed as well.

γ-graphdiyne is a two-dimensional (2D) carbon structure beyond graphene: it is formed by $sp$ and $s{p}^2$ carbon atoms organized as hexagonal rings connected by linear links, and it is predicted to be a semiconductor. The lateral confinement of γ-graphdiyne nanoribbons significantly affects the electronic and vibrational properties. By means of periodic density-functional theory (DFT) calculations we here investigate the electronic band structure, the Raman and IR spectra of γ-graphdiyne 2D crystal and related nanoribbons. We discuss the effect of the functional and basis set on the evaluation of the band gap, highlighting the reliability of hybrid functionals. By joining DFT calculations with a symmetry analysis, we assign in detail the IR and Raman spectra of γ-graphdiyne. On this basis we show the modulation of the gap in nanoribbons of increasing width and different edges (armchair, zigzag). We assess how confinement affects the Raman and IR spectra by comparing vibrational modes with phonons of the parent 2D crystal. Our symmetry-based classification allows identifying the marker bands sensitive to the edge structure and lateral confinement of nanoribbons of increasing width. These results show the effectiveness of vibrational spectroscopy for the characterization of such nanostructures.

Direct observation of temperature dependence of individual bands of semiconductors for a wide temperature region is not straightforward, in particular. However, this fundamental property is a prerequisite in understanding the electron-phonon coupling of semiconductors. Here we apply ab initio many-body perturbation theory to the electron-phonon coupling on hexagonal silicon carbide (SiC) crystals and determine the temperature dependence of the bands. We find a significant electron-phonon renormalization of the band gap at 0 K. Both the conduction and valence bands shift at elevated temperatures, exhibiting a different behavior. We compare our theoretical results with the observed thermal evolution of SiC band edges, and discuss our findings in the light of high-temperature SiC electronics and defect qubits operation.