The mode of intermolecular arrangements is crucial in determining organic semiconductor (OSC) device performance, although the method for controlling the arrangements has not yet been established. Here it is demonstrated that mixing OSC molecules with different lengths of substituted alkyl chains allows the emergence of a distinct high-mobility polymorphic phase in alkylated layered crystalline OSCs. The pristine OSC molecules of $para$-tolyl/alkylated-[1]benzothieno[3,2-$b]$[1]benzothiophene ($p\mathrm{Tol}\text{−}\mathrm{BTBT}\text{−}{\mathrm{C}}_n$) at $n$ $=6$ and 8 both exhibit a low-mobility isomorphous phase in the crystalline film states. By contrast, a distinct polymorphic phase showing much higher mobility emerges as a result of equimolar mixing of $p\mathrm{Tol}\text{−}\mathrm{BTBT}\text{−}{\mathrm{C}}_n$ at $n$ $=6$ and 8 during the film-coating process. The mixing-induced phase presents tenfold enhanced mobility compared with pure compounds, accompanied by a drastic polymorphic transformation. The emerging technique of electron diffraction structure analysis reveals that interlayer alkyl chain interdigitation involving close tail-to-tail packing plays a significant role in stabilizing the mixing-induced phase. The analysis of polarized absorption spectra indicates that a metastable liquid-crystalline (LC) phase is formed prior to the crystallization, implying that the formation of the mixing-induced phase is promoted by the intralayer molecular diffusion motion within the metastable LC phase. The finding of the controllable nature of layered crystallinity should lead to high-end printed electronics.

We use scanning tunneling microscopy and spectroscopy under ultrahigh vacuum and down to 1.7 K to study the local variations of the chemical potential on the surface of the topological insulator ${\left({\mathrm{Bi}}_{1-x}{\mathrm{Sb}}_x\right)}_2{\mathrm{Te}}_3$ thin films (thickness $7–30\mathrm{nm}$) with varying Sb concentration $x$, to gain insight into the charge puddles formed in thin films of a compensated topological insulator. We found that the amplitude of the potential fluctuations, $\mathrm{\Gamma }$, is between 5 and 14 meV for quasi-bulk-insulating films and about $30–40\mathrm{meV}$ for bulk-insulating films. The length scale of the fluctuations, $\lambda$, was found to span the range of $13–54\mathrm{nm}$, with no clear correlation with $\mathrm{\Gamma }$. Applying a magnetic field normal to the surface, we observe the condensation of the two-dimensional topological surface state into Landau levels and find a weak but positive correlation between $\mathrm{\Gamma }$ and the spectral width of the Landau-level peaks, which suggests that quantum smearing from drift motion is the source of the Landau-level broadening. Our systematic measurements give useful guidelines for realizing ${\left({\mathrm{Bi}}_{1-x}{\mathrm{Sb}}_x\right)}_2{\mathrm{Te}}_3$ thin films with an acceptable level of potential fluctuations. In particular, we found that $x\approx 0.65$ realizes the situation where $\mathrm{\Gamma }$ shows a comparatively small value of 14 meV and the Dirac point lies within $\sim 10\mathrm{meV}$ of the Fermi energy.

Layered transition metal dichalcogenides (TMDs) stabilize in multiple structural forms with profoundly distinct and exotic electronic phases. Interfacing different layer types is a promising route to manipulate TMDs' properties, not only as a means to engineer quantum devices but also as a route to explore fundamental physics in complex matter. Here we use angle-resolved photoemission (ARPES) to investigate a strong layering-dependent enhancement of superconductivity in ${\mathrm{TaS}}_2$, in which the superconducting transition temperature, $T_c$, of its $2H$ structural phase is nearly tripled when insulating $1T$ layers are inserted into the system. The study is facilitated by a vanadium-intercalation approach to synthesizing various ${\mathrm{TaS}}_2$ polytypes, which improves the quality of the ARPES data while leaving key aspects of the electronic structure and properties intact. The spectra show the clear opening of the charge density wave gap in the pure $2H$ phase and its suppression when $1T$ layers are introduced to the system. Moreover, in the mixed-layer $4Hb$ system, we observe a strongly momentum-anisotropic increase in electron-phonon coupling near the Fermi level relative to the $2H$ phase. Both phenomena help to account for the increased $T_c$ in mixed $2H/1T$ layer structures.

The chromium-trihalides ($\mathrm{Cr}{X}_3$; $X=\mathrm{Cl}$, Br, I) have long served as model systems for understanding magnetism and magneto-optics in ionic crystals and they have recently also emerged as archetypes of magnetic two-dimensional (2D) van der Waals materials. Although the physical properties of $\mathrm{Cr}{X}_3$ compounds have now been explored in great depth, the use of impurity doping to generate new properties remains surprisingly underexplored. Here we report on the magnetic and magneto-optical properties of lanthanide-doped ${\mathrm{CrBr}}_3$, in which ${\mathrm{Yb}}^{3+}$ is introduced as a spin-bearing optical point defect. Narrow-line near-infrared dopant photoluminescence is efficiently sensitized by ${\mathrm{CrBr}}_3$-to-${\mathrm{Yb}}^{3+}$ energy transfer. Magneto-optical measurements show facile spin manipulation of the paramagnetic ${\mathrm{Yb}}^{3+}$ impurities by the surrounding ${\mathrm{CrBr}}_3$ lattice. Photoluminescence data reveal that the Kramers spin degeneracies of the ground- and excited-state ${\mathrm{Yb}}^{3+}$ doublets are spontaneously lifted by strong magnetic exchange with neighboring ${\mathrm{Cr}}^{3+}$ ions, such that individual ${\mathrm{Yb}}^{3+}$ spin transitions are easily resolved even at zero external magnetic field. The temperature and field dependence of these splittings can be used to probe both local and long-range spin correlations. These results highlight the use of extrinsic optical impurities to add new spin-photonic functionality to this classic 2D van der Waals magnet.

In biology, mechanosensitive ion channels facilitate the conversion of mechanical stimuli, such as sound and touch, into electrical signals. Similar functionality in artificial systems was recently predicted in the form of stretch-activated transport through porous 2D membranes. Here we describe an opposite behavior, in which ion transport is inactivated upon stretching a subnanoporous 2D membrane. We explore electrophoretic ion transport through several subnanoporous membranes using molecular dynamics simulations. We demonstrate that aqueous ${\mathrm{K}}^{+}$ transport decreases by a factor of 3–8 under stretching of order 3%. In contrast, ${\mathrm{Na}}^{+}$ ions exhibit transport activation by stretching, suggesting ion-dependent activation and inactivation in a single membrane. Our analysis shows that inactivation of ${\mathrm{K}}^{+}$ transport is caused by a strain-induced repulsive-to-attractive transition in the ${\mathrm{K}}^{+}$-pore interactions due to alignment of the local energy minima.

Two-dimensional semiconductors present unique opportunities to intertwine optical and magnetic functionalities and to tune these performances through defects and dopants. Here, we integrate exciton pumping into a quantum sensing protocol on nitrogen-vacancy centers in diamond to image the optically induced transient stray fields in few-layer, antiferromagnetic ${\mathrm{CrCl}}_3$. We discover that exciton recombination enhances the in-plane magnetization of the ${\mathrm{CrCl}}_3$ layers, with a predominant effect in the surface monolayers. Concomitantly, time-resolved photoluminescence measurements reveal that nonradiative exciton recombination intensifies in atomically thin ${\mathrm{CrCl}}_3$ with tightly localized, nearly dipole-forbidden excitons and amplified surface-to-volume ratio. Supported by experiments under controlled surface exposure and density functional theory calculations, we interpret the magnetically enhanced state to result from a defect-assisted Auger recombination that optically activates electron transfer between water vapor related surface impurities and the spin-polarized conduction band. Our work validates defect engineering as a route to enhance intrinsic magnetism in single magnetic layers and opens an experimental platform for studying optically induced, transient magnetism in condensed matter systems.

We present that $\mathrm{M}{\mathrm{n}}_{4-x}\mathrm{C}{\mathrm{u}}_x\mathrm{N}$ films grown by molecular beam epitaxy on $\mathrm{SrTi}{\mathrm{O}}_3$(001) have a magnetic compensation (MC) composition with noncollinear magnetic components at room temperature. Due to the high crystalline quality and perpendicular magnetic anisotropy, the remanent magnetization ratio was almost 100% for $x\le 0.6$. At 0.10 ≤ $x\le 0.15$, the saturation magnetization was the smallest, while the coercivity was the largest. The hysteresis curves obtained by both the magneto-optical Kerr effect and the anomalous Hall effect showed sign reversal between $x=0.1$ and 0.15. X-ray magnetic circular dichroism (XMCD) spectra at the Cu $L_{2,3}$ edges also showed sign reversal over the entire energy range. These results provide evidence that the MC composition is in the vicinity of $x\sim 0.1$. However, the XMCD spectra at the Mn $L_{2,3}$ edges showed a different magnetic structure change from that of Ni-doped $\mathrm{M}{\mathrm{n}}_4\mathrm{N}$, which also exhibits MC. A magnetic structure model for $\mathrm{M}{\mathrm{n}}_{4-x}\mathrm{C}{\mathrm{u}}_x\mathrm{N}$ is discussed in comparison with the experimental results.

Topological Hall effect (THE) is a hallmark of scalar spin chirality, which is found in static skyrmion lattices. Recent theoretical works have shown that scalar spin chirality could also emerge dynamically from thermal spin fluctuations. Evidence of such a mechanism was found in the kagome magnet $\mathrm{Y}{\mathrm{Mn}}_6{\mathrm{Sn}}_6$ where fluctuations arise from frustrated exchange interactions between Mn kagome layers. In $\mathrm{Y}{\mathrm{Mn}}_6{\mathrm{Sn}}_6$, the rare-earth ion ${\mathrm{Y}}^{3+}$ is nonmagnetic. When it is replaced by a magnetic ion $({\mathrm{Gd}}^{3+}-{\mathrm{Ho}}^{3+})$, the intrinsically antiferromagnetic Mn-Mn interlayer coupling is overwhelmed by the indirect ferromagnetic $\mathrm{Mn}\text{−}R\text{−}\mathrm{Mn}$ one, relieving frustration. This generates interesting anomalous Hall conductivity, but not THE. Here we show that Er lies in an intermediate regime where direct and indirect interactions closely compete, so that $\mathrm{Er}{\mathrm{Mn}}_6{\mathrm{Sn}}_6$ can switch from one regime to the other by temperature, i.e., from a collinear ferrimagnetic ground state to a spiral antiferromagnet at 78 K. The antiferromagenetic  phase forms a dome in the temperature-field phase diagram. Close to the boundary of this dome, we find a sizable fluctuations-driven THE, thus underscoring the universality of this chiral fluctuation mechanism for generating nonzero scalar spin chirality.

A threshold dynamics model of grain growth that accounts for the anisotropy in the grain boundary energy has been used to simulate experimentally observed grain growth of polycrystalline Ni. The simulation reproduces several aspects of the observed microstructural evolution that are not found in the results of simulations assuming isotropic properties. For example, the relative areas of the lowest-energy twin boundaries increase as the grains grow and the average grain boundary energy decreases with grain growth. This decrease in energy occurs because the population of higher-energy grain boundaries decreases while the population of lower-energy boundaries increases as the total grain boundary area decreases. This phenomenon emerges from the assumption of anisotropic grain boundary energies without modification of the energy minimizing algorithm. These findings are consistent with the observation that, in addition to the decrease in grain boundary area, additional energy is dissipated during grain growth by a decrease in the average grain boundary energy.

This work explores the luminescence properties of melt-grown ${\mathrm{ZnGa}}_2{\mathrm{O}}_4$ single crystals using photoluminescence spectroscopy and first-principles calculations. The photoluminescence spectra consist of numerous overlapping broad bands in the spectral range between 1.4 and 3.9 eV, which can be divided into low- (1.4–2.7 eV) and high-energy (2.7–3.9 eV) parts. When using below-gap excitation, the photoluminescence spectrum shows distinct orange and ultraviolet luminescence bands peaking at 1.99 and 3.36 eV, respectively. The results are interpreted by using configuration coordinate diagrams derived from hybrid functional calculations for self-trapped holes, as well as for the most stable native defects and their complexes. The calculations show that self-trapped holes, Zn antisites, and Zn-Ga antisite pairs give rise to strongly overlapping luminescence lines that are compatible with the high-energy side of the broad emission. For the low-energy side, we suggest Zn vacancies and their complexes with Ga antisites as potential intrinsic origins. The calculated Zn vacancy lineshape fits well with the orange luminescence band. Ga vacancies are unlikely to be the origin of the observed visible and ultraviolet emission, as the calculated luminescence lines occur in the infrared region. Moreover, complexes between the Ga vacancy and one or two Ga antisites, which would show luminescence at higher energies, are only metastable. It is more favorable for a Ga antisite to jump into the Ga vacancy, replacing the Ga antisite and vacancy with a Zn vacancy.

A newly identified magnetic phase called altermagnet is being actively studied because of its unprecedented spin-dependent phenomena. Among the candidate materials, CrSb has a particularly high ordering temperature and a large spin-splitting energy, but its transport properties have remained unexplored. In this study, we report the magnetotransport properties of CrSb measured on single crystals. We found that the Hall resistivity shows a nonlinear dependence on the magnetic field at low temperatures. From symmetry-based considerations, however, this behavior cannot be attributed to an anomalous Hall effect, but to a multicarrier effect. A multicarrier fitting to the in-plane conductivity tensor revealed the presence of carriers with high mobility in CrSb, which is an advantage for efficient spin current generation.

Magnetic topological insulators provide a platform for emergent phenomena arising from the interplay between magnetism and band topology. Here we report the single crystal growth, crystal structure, magnetic and transport properties, as well as the neutron scattering studies of topological insulator series ${\left({\mathrm{Ge}}_{1-\delta -x}{\mathrm{Mn}}_x\right)}_2{\mathrm{Bi}}_2{\mathrm{Te}}_5$ $(x\le 0.47, 0.11\le \delta \le 0.20)$. Upon doping up to $x=0.47$, the lattice parameter $c$ decreases by 0.8%, while the lattice parameter $a$ remains nearly unchanged. Significant Ge vacancies and Ge/Bi site mixing are revealed via elemental analysis as well as refinements of the neutron and x-ray diffraction data, resulting in holes dominating the charge transport. At $x=0.47$, below 10.8 K, a bilayer A-type antiferromagnetic ordered state emerges, featuring an ordered moment of 3.0(3) ${\mu }_B/\mathrm{Mn}$ at 5 K, with the $c$ axis as the easy axis. Magnetization data unveils a much stronger effective interlayer antiferromagnetic exchange interaction and a much smaller uniaxial anisotropy compared to ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$. We attribute the former to the shorter nearest-neighbor Mn-Mn interlayer superexchange path and the latter to the smaller ligand-field splitting in ${\left({\mathrm{Ge}}_{1-\delta -x}{\mathrm{Mn}}_x\right)}_2{\mathrm{Bi}}_2{\mathrm{Te}}_5$. Our study demonstrates that this series of materials holds promise for the investigation of the layer Hall effect and quantum metric nonlinear Hall effect.

We report a comparative study of temperature-dependent photoluminescence and structural dynamics of two perovskite semiconductors, the chalcogenide ${\mathrm{BaZrS}}_3$ and the halide $\mathrm{Cs}\mathrm{Pb}{\mathrm{Br}}_3$. These materials have similar crystal structures and direct band gaps, but we find that they have quite distinct optoelectronic and vibrational properties. Both materials exhibit thermally activated nonradiative recombination, but the nonradiative recombination rate in ${\mathrm{BaZrS}}_3$ is four orders of magnitude faster than in $\mathrm{Cs}\mathrm{Pb}{\mathrm{Br}}_3$, for the crystals studied here. Raman spectroscopy reveals that the effects of phonon anharmonicity are far more pronounced in $\mathrm{Cs}\mathrm{Pb}{\mathrm{Br}}_3$ than in ${\mathrm{BaZrS}}_3$. Further, although both materials feature a large dielectric response due to low-energy polar optical phonons, the phonons in $\mathrm{Cs}\mathrm{Pb}{\mathrm{Br}}_3$ are substantially lower in energy than in ${\mathrm{BaZrS}}_3$. Our results suggest that electron-phonon coupling in ${\mathrm{BaZrS}}_3$ is more effective at nonradiative recombination than in $\mathrm{Cs}\mathrm{Pb}{\mathrm{Br}}_3$ and that ${\mathrm{BaZrS}}_3$ may also have a substantially higher concentration of nonradiative recombination centers than $\mathrm{Cs}\mathrm{Pb}{\mathrm{Br}}_3$. The low defect concentration in $\mathrm{Cs}\mathrm{Pb}{\mathrm{Br}}_3$ may be related to the ease of lattice reconfiguration, typified by anharmonic bonding. It remains to be seen to what extent these differences are inherent to the chalcogenide and halide perovskites and to what extent they can be affected by materials processing.

Intrinsic magnetic topological insulators, in which magnetism and topology are inherently combined, are excellent systems to realize exotic phenomena such as the quantum anomalous Hall effect. However, there are many reports that show that the experimental samples are not so ideal and the effect of the unintentional disorder in these systems needs to be considered carefully. In this study, we investigate the role of misplaced magnetic atoms as well as nonmagnetic elements in the intrinsic magnetic topological insulator heterostructures based on ${\mathrm{MnBi}}_2{\mathrm{Se}}_4$ and ${\mathrm{Bi}}_2{\mathrm{Se}}_3$. We find that Mn atoms are not only placed at the central layer of the ${\mathrm{MnBi}}_2{\mathrm{Se}}_4$ septuple layer (SL) but also intermix with Bi (antisite Mn) as well as reside in the van der Waals (vdW) gap. Through a detailed comparison between the experimental and theoretical x-ray magnetic circular dichroism (XMCD) spectra, we find that the antisite Mn is coupled ferromagnetically, whereas the vdW Mn couple antiferromagnetically to the Mn in the central atomic plane of the SL. Furthermore, we detect a clear XMCD signal in nonmagnetic Se, providing unambiguous evidence of its magnetic interaction with Mn.

Using coarse-grained molecular dynamics simulations, we study the mechanical properties and stress transfer mechanisms of weakly entangled, glassy polymer blends compatibilized by diblock, triblock, or pentablock copolymers. For a given number of copolymer junctions per unit area, copolymer architecture is found to play a minimal role, whereas block degree of polymerization and copolymer loading qualitatively impact the interfacial mechanics. Explicitly, the stress-strain and density-strain curves reveal distinctly different deformation mechanisms at low and high compatibilizer loading related to cavitation and fibril formation near the A/B interface. Furthermore, the competition between interfacial cavitation and chain pullout from the bulk leads to nonmonotonic dependencies of the toughness and strain-at-break on copolymer loading. For sufficiently long copolymers, the simulations predict an optimum loading that produces mechanical properties that nearly match those of the homopolymer glass. These results imply that moderate loading of long block copolymers is ideal for effective compatibilization and stress transfer across the interface.

Colloidal gels undergo a phenomenon known as physical aging, i.e., a continuous change of their physical properties with time. To date, most of the research effort on aging in gels has been focused on suspensions of hard colloidal particles. In this Letter, we tackle the case of soft colloidal “micelles” comprised of proteins, in which gelation is induced by the addition of an enzyme. Using time-resolved mechanical spectroscopy, we monitor the viscoelastic properties of a suspension of colloidal micelles through the sol-gel transition and subsequent aging. We show that the microscopic scenario underpinning the macroscopic aging dynamics comprises two sequential steps. First, the gel microstructure undergoes rapid coarsening, as observed by optical microscopy, followed by arrest. Second, aging occurs solely through a contact-driven mechanism, as evidenced by the square-root dependence of the yield stress with the elastic modulus measured at different ages of the gel. These results provide a comprehensive understanding of aging in enzymatic milk gels, crucial for a broad range of dairy products, and for soft colloids in general.

Hydrogen-enhanced decohesion (HEDE) is one of the many mechanisms of hydrogen embrittlement, a phenomenon that severely impacts structural materials such as iron and iron alloys. Grain boundaries (GBs) play a critical role in this mechanism, where they can provide trapping sites or act as hydrogen diffusion pathways. The interaction of H with GBs and other crystallographic defects, and thus the solubility and distribution of H in the microstructure, depends on the concentration, chemical potential, and local stress. Therefore, for a quantitative assessment of HEDE, a generalized solution energy in conjunction with the cohesive strength as a function of hydrogen coverage is needed. In this paper, we carry out density functional theory calculations to investigate the influence of H on the decohesion of the $\mathrm{\Sigma }5\left(310\right)\left[001\right]$ and $\mathrm{\Sigma }3\left(112\right)\left[1\overline{1}0\right]$ symmetrical tilt GBs in bcc Fe, as examples for open and close-packed GB structures. A method to identify the segregation sites at the GB plane is proposed. The results indicate that at higher local concentrations, H leads to a significant reduction of the cohesive strength of the GB planes, significantly more pronounced at the $\mathrm{\Sigma }5$ than at the $\mathrm{\Sigma }3$ GB. Interestingly, at finite stress, the $\mathrm{\Sigma }3$ GB becomes more favorable for H solution, as opposed to the case of zero stress, where the $\mathrm{\Sigma }5$ GB is more attractive. This suggests that, under certain conditions, stresses in the microstructure can lead to a redistribution of H to the stronger grain boundary, which opens a path to designing H-resistant microstructures. To round up our study, we investigate the effects of typical alloying elements in ferritic steel, C, V, Cr, and Mn, on the solubility of H and the strength of the GBs.

We outline how pairs of strongly immiscible elements, referred to here as antagonistic pairs, can be used to synthesize ternary compounds with low or quasi-reduced-dimensional motifs intrinsically built into their crystal structures. By identifying third elements that are mutually compatible with a given antagonistic pair, ternary compounds can be formed in which the third element segregates the immiscible atoms into spatially separated substructures. Quasi-low-dimensional structural units, such as sheets, chains, or clusters are a natural consequence of the immiscible atoms seeking to avoid close contact in the solid state. As proof of principle, we present the discovery, crystal growth, and basic physical properties of ${\mathrm{La}}_4{\mathrm{Co}}_{4}X$ (X = Pb, Bi, Sb), a family of intermetallic compounds based on the antagonistic pairs Co-Pb and Co-Bi. ${\mathrm{La}}_4{\mathrm{Co}}_{4}X$ adopts an orthorhombic crystal structure (space group Pbam) containing quasi-two-dimensional Co slabs and La-X polyhedra that stack in an alternating manner along the $a$ axis. Consistent with our proposal, the La atoms separate the Co and X substructures, ensuring there are no direct contacts between the members of the immiscible (antagonistic) pair. Within the Co slabs, the atoms occupy the vertices of corner sharing tetrahedra and triangles, and this bonding motif produces narrow electronic bands near the Fermi level that favor magnetism. The Co is moment bearing in each ${\mathrm{La}}_4{\mathrm{Co}}_{4}X$ compound studied, and we show that whereas ${\mathrm{La}}_4{\mathrm{Co}}_4\mathrm{Pb}$ behaves as a three-dimensional antiferromagnet with T${}_{\text{N}}=220\mathrm{K}$, ${\mathrm{La}}_4{\mathrm{Co}}_4\mathrm{Bi}$ and ${\mathrm{La}}_4{\mathrm{Co}}_4\mathrm{Sb}$ have behavior consistent with low-dimensional magnetic coupling and ordering, with T${}_{\text{N}}=153\mathrm{K}$ and 143 K, respectively. In addition to the Pb-, Bi-, and Sb-based ${\mathrm{La}}_4{\mathrm{Co}}_{4}X$ compounds, we also were likely able to produce an analogous ${\mathrm{La}}_4{\mathrm{Co}}_4\mathrm{Sn}$ in polycrystalline form, although we were unable to isolate single crystals. We anticipate that identifying and using mutually compatible third elements together with an antagonistic pair represents a generalizable design principle for discovering new materials and new structure types containing low-dimensional substructures.

Recent intensive studies in metallic kagome systems have revealed various correlated topological and electronic states, leading to their spintronic applications. The kagome ferromagnetic metal ${\mathrm{Fe}}_3\mathrm{Sn}$ has been found to host a topological nodal plane near the Fermi energy and exhibits large transverse transport responses. Here we report the fabrication of the epitaxial thin films of ${\mathrm{Fe}}_3\mathrm{Sn}$ and the observation of its large anomalous Nernst effect (ANE). Structural and magnetic measurements reveal (0001)-orientated epitaxial growth of kagome $D{0}_{19}$ ${\mathrm{Fe}}_3\mathrm{Sn}$ and the magnetic easy plane along the substrate plane. Moreover, transport measurements confirm the large ANE of 2.4 µV/K at room temperature, comparable to that of the bulk polycrystalline samples. The obtained ${\mathrm{Fe}}_3\mathrm{Sn}$ film should be useful for thermoelectric applications, because the binary compound based on inexpensive elements exhibits large spontaneous ANE voltage under an out-of-plane heat current due to the magnetic and electronic states stabilized by the magnetic anisotropy.

Compared to time-reversal symmetry-protected ${\mathbb{Z}}_2$ topological insulators and Dirac/Weyl semimetals, there are significantly fewer candidates for topological crystalline insulators. ${\mathrm{SrAg}}_4{\mathrm{Sb}}_2$ is predicted to exhibit topological crystalline insulator behavior when considering spin-orbit coupling. In this study, we systematically investigate single crystals of ${\mathrm{SrAg}}_4{\mathrm{Sb}}_2$ using electrical transport and magnetic torque measurements, along with first-principles calculations. Our transport data reveals its compensated semimetal nature with a magnetoresistance up to around 700% at 2 K and 9 T. Analysis of de Haas–van Alphen oscillations uncovers a Fermi surface consisting of three distinct Fermi pockets with light effective masses. Comparison between the three-dimensional fermiology obtained from our oscillation data and the first-principles calculations demonstrates excellent agreement. This confirms the accuracy of the calculations, which indicate a band inversion centered at the $T$ point and identify the existence of nontrivial tube and needle hole Fermi pockets at $\mathrm{\Gamma }$, alongside one trivial diamond electron pocket at the $F$ point in the Brillouin zone. Furthermore, symmetry and topology analysis results in two potential sets of topological invariants, suggesting the emergence of two-dimensional gapless Dirac surface states either on the $ab$ planes or on both the $ab$ planes and mirror planes, protected by crystal symmetries. Therefore, ${\mathrm{SrAg}}_4{\mathrm{Sb}}_2$ emerges as a promising candidate topological crystalline insulator.