Very recently, a $3d$ based honeycomb cobaltate ${\mathrm{Na}}_2{\mathrm{Co}}_2{\mathrm{TeO}}_6$ has garnered tremendous attention due to the proposed proximity to the Kitaev spin-liquid state as its $4d/5d$ counterparts. Here, we use Zn to substitute Co in a broad range and perform systematic studies on ${\mathrm{Na}}_2{\mathrm{Co}}_{2-x}{\mathrm{Zn}}_x{\mathrm{TeO}}_6$ by structural, magnetic, and thermodynamic measurements, and track the doping evolution of its magnetic ground states. Due to the extremely close radii of ${\mathrm{Zn}}^{2+}$ and high-spin ${\mathrm{Co}}^{2+}$ ions, the substitution can be easily achieved. X-ray diffractions reveal no structural transition but only minor changes on the lattice parameter $c$ over a wide substitution range $0\le x\le 1.5$. Magnetic susceptibility and specific heat measurements both suggest an antiferromagnetic ground state which is gradually suppressed with doping. It can survive with $x$ up to $\sim 1.0$. Then it evolves into a spin-glass phase with short-range order that is rapidly supplanted by a magnetically disordered state when $x\ge 1.3$. By summarizing all these data, we construct a magnetic phase diagram of ${\mathrm{Na}}_2{\mathrm{Co}}_{2-x}{\mathrm{Zn}}_x{\mathrm{TeO}}_6$. Our results demonstrate that the Zn doping can effectively suppress the magnetic order and induce a possible quantum paramagnetic state. These may serve as a platform to investigate the Kitaev physics in this system.

Work-function $\varphi$ measures the work needed for an electron to escape a solid. For simple metals, it is almost exclusively the result of the surface dipole created by spill-out of electrons from bulk into the vacuum as shown in the seminal work by Lang and Kohn [Phys. Rev. B 3, 1215 (1971)] using a jellium model. Despite a half century of intense efforts, however, such understanding has not been extended past metals. Here we present a universal model for $\varphi$ which contains a previously unrecognized bulk contribution ${\varphi }_I$ [Phys. Rev. Lett. 121, 196802 (2018)]. By incorporating ${\varphi }_I$ into the jellium model, we find that it dictates the dipole due to charge spill out and provides a description which applies to a wide range of materials, ranging from metals, semiconductors, to insulators.

It was experimentally reported that II-VI group inorganic semiconductor crystals become harder and brittle by external light illumination. In order to reveal essential factors of the light illumination effect, systematic $\mathrm{GGA}+U$ calculations are performed for 30° partial dislocations in ZnSe and ZnTe, and the obtained results are discussed together with those for ZnS reported previously. It is found in these three crystal systems that the cores of pristine partial dislocations have unreconstructed atomic structures whereas their cores undergo atomic reconstruction energetically more favorably by trapping excess carriers. Such carrier trapping and atomic reconstruction of the dislocation cores are ascribed to the presence of excess electrostatic potentials at the cores due to ionic bonding characters of the host crystals. The dislocation core reconstructions decrease potential energies of the partial dislocations and can in turn increase Peierls-potential barriers for dislocation glide, corresponding to the observed hardening and brittleness by light illumination. The energy gains due to the dislocation-core reconstructions also depend on energy positions of the defect-induced levels that appear within the band gaps.

In this paper we report a detailed ESR spectroscopic study of the single-crystalline samples of the van der Waals compounds ${\mathit{M}}_{\text{2}}{\mathrm{P}}_{\text{2}}{\mathrm{S}}_{\text{6}}$ (${\mathit{M}}_{\text{2}}={\mathrm{Mn}}_{\text{2}}$, MnNi, ${\mathrm{Ni}}_{\text{2}}$), performed at an excitation frequency of 9.56 GHz, in a broad range of temperatures above the magnetic order, and at different orientations of the magnetic field with respect to the sample. Analyzing temperature and angular dependencies of the resonance field and of the linewidth of the ${\mathrm{Mn}}_2{\mathrm{P}}_2{\mathrm{S}}_6$ compound we have observed a significant change of the spin dynamics from the dominance of the 3D-like fluctuations close to the magnetic order to a relative increase of the 2D-like spin fluctuations at higher temperatures. Such a behavior, which is opposite to the development of the low-D signatures in the previously studied ${\mathrm{Cr}}_{\text{2}}{\mathrm{Ge}}_{\text{2}}{\mathrm{Te}}_{\text{6}}$ compound, can be explained by the difference in the type of magnetic order in ${\mathrm{Mn}}_2{\mathrm{P}}_2{\mathrm{S}}_6$ and ${\mathrm{Cr}}_{\text{2}}{\mathrm{Ge}}_{\text{2}}{\mathrm{Te}}_{\text{6}}$. On the other hand, ${\mathrm{MnNiP}}_2{\mathrm{S}}_6$ compound exhibits angular dependencies of the linewidth typical for the system with 3D-like spin correlations in the whole measurement temperature range, however the 2D-like correlations can be seen in the temperature dependencies of the resonance field and the linewidth. ${\mathrm{Ni}}_2{\mathrm{P}}_2{\mathrm{S}}_6$, in turn, does not show any 2D signatures. This suggests that varying the Ni content in ${\left({\mathrm{Mn}}_{1-x}{\mathrm{Ni}}_x\right)}_2{\mathrm{P}}_2{\mathrm{S}}_6$ one can control the exchange interaction, possibly also in the third dimension.

Evaluation of the bidirectional magnetoelectric (ME) effect using a ${\mathrm{BiFeO}}_3$ (BFO)/NiFeCuMo bilayer reveals that the electronically controlled ME effect ($E\mathrm{\to }M$) and magnetically controlled ME effect ($H\mathrm{\to }P$) have individual origins. (i) ME effect ($H\mathrm{\to }P$): The ferroelectric polarization, evaluated using the hysteresis loops and positive-up–negative-down method, changed quadratically as a function of the magnetic field. This quadratic change is evidence of a cycloidal magnetic structure like that of bulk BFO. (ii) ME effect ($E\mathrm{\to }M$): Magnetization switching was observed via electric-field-induced ferroelectric polarization switching through an $H_{\mathrm{EB}}$. In principle, the cycloidal magnetic structure does not exhibit an electrically controlled ME effect owing to the disappearance of $H_{\mathrm{EB}}$ because BFO ${\left(001\right)}_{\mathrm{pc}}$ is the compensated plane. However, an uncompensated weak ferromagnetic (FM) interface emerged near the BFO/NiFeCuMo by interfacial roughness, strains and defect rather than interfacial oxidation, resulting in $H_{\mathrm{EB}}$. An analysis of the bidirectional ME effect mechanism revealed that a hybrid of the cycloidal magnetic structure in the entire film body and uncompensated weak FM emerged near the interface, which developed BFO as an advanced cycloidal/uncompensated antiferromagnetic multiferroic. In addition, the strong $H_{\mathrm{EB}}$ realized perfect switching of magnetization polarities at zero electric fields, and the highly oriented ferroelectric domain realized the repetition of the ME effect.

Doping of magnetostrictive galfenol (${\mathrm{Fe}}_{82}{\mathrm{Ga}}_{18}$, in at. %) with rare-earth elements significantly enhances magnetostriction, with the largest gains achieved in textured melt-spun ribbons. Here, it is demonstrated that even extremely dilute Ce, as little as 65 ppm, can double the magnetostrictive response of galfenol when coupled with an appropriate heat treatment. This improvement is correlated with a compression of the host lattice, both of which reach their maximum extent at the calculated solubility limit of Ce in in body-centered cubic (bcc) galfenol, $\sim 50\mathrm{ppm}$. Beyond this point, excess Ce segregates into $\mathrm{Ce}{\mathrm{Ga}}_2$, which forms an interdendritic network throughout the sample at high Ce levels and cannot be resolutionized through heat treatments. These findings point to the importance of solubility limits (i.e., equilibrium thermodynamics) in determining appropriate doping levels or heat treatment couples to optimize magnetostrictive performance, confirming that overdoping is actively detrimental to both material properties and cost.

We investigated $\mathrm{Nb}{\mathrm{O}}_2$ thin films grown by pulsed-laser deposition on ${\mathrm{Al}}_2{\mathrm{O}}_3$(0001) substrates. Increasing the growth temperature from 700 to $900{}^{\circ }\mathrm{C}$, a clear improvement of the structural quality and the interface abruptness has been observed for the epitaxial films, together with an increase in the average grain size from tens of nanometers to above 100 nm. For achieving high film resistivities, increasing the average grain size is found to be crucial. For a more detailed investigation of the carrier transport characteristics, Raman spectroscopy is demonstrated as a powerful tool. In the case of relatively large grain sizes, we reveal that the film resistivities directly correlate with the carrier concentration in the $\mathrm{Nb}{\mathrm{O}}_2$ grains. The results obtained for comparatively small grain sizes can be explained by carrier transport via a percolation mechanism along metallic grain boundaries in accordance with a previously reported model.

Two-dimensional (2D) binary compound materials composed of group-V elements are hot spots owing to the unique easy-to-design symmetry-broken structures and excellent physical and chemical properties. In this paper, the stability and corresponding piezoelectric properties of group-V binary compounds $AB$ ($A,B=\text{N}$, P, As, Sb, Bi, and $A\ne B$) with different structure phases are systematically investigated by performing first-principles calculations. The calculations show that the group-V binary compounds always exhibit six types of a structure phase with a relative low energy, i.e., $\alpha$, $\beta$, $\gamma$, $\delta$, $\lambda$, and $\psi$ phases. More interestingly, compared to the obvious piezoelectric effect reported in the $\alpha$ phase of group-V binary compounds, a giant piezoelectric coefficient is revealed in $\psi$-SbP and $\psi$-BiP, where ${\mathit{d}}_{11}$ is evaluated as high as 263.77 and 298.48 pm/V, respectively. Such a superb piezoelectric performance in $\psi$-SbP and $\psi$-BiP even exceeds the previously reported 2D piezoelectric material SnSe (${\mathit{d}}_{11}=250.58$ pm/V), which is mainly originated from a unique flexible structure and special symmetry. The mechanical, dynamical, and thermal stabilities of $\psi$-BiP and $\psi$-SbP are verified by the Born-Huang criterion, phonon spectrum, and ab initio molecular dynamics simulations. The findings presented in this paper shed light on the structure and piezoelectric properties of group-V binary compounds, and provide valuable guidance for their potential applications in flexible sensors and the energy harvesting community.

The realization of Weyl systems with the minimum nonzero number of Weyl points (WPs) and full spin polarization remains challenging in topology physics and spintronic. In this paper, we used first-principles calculations and symmetry analysis to demonstrate that ${\mathrm{BaNiIO}}_6$, a dynamically and thermodynamically stable half-metallic material, hosts fully spin-polarized single-pair (SP) WPs with a charge number ($\mathcal{C}$) of $\pm 2$ and a type-III band dispersion around the Fermi level. Moreover, the fully spin-polarized SP-WPs induce double-helicoid Fermi arcs on the ($10\overline{1}0$) surface. The half-metallic state and the spin-polarized SP-WPs are robust to uniform strains (from $-10$ to $+8\%$) and onsite Hubbard-Coulomb interactions (from 0 to 6 eV). When $+9$ or $+10\%$ uniform strain is applied to the ${\mathrm{BaNiIO}}_6$ system, it hosts six additional type-II WPs with $\left|\mathcal{C}\right|=1$ in the three-dimensional Brillouin zone in addition to the two type-III WPs with $\left|\mathcal{C}\right|=2$. We hope that this paper will motivate future research into SP-WPs half-metals.

We develop a two-orbital Hubbard model of electron correlations in ultrathin (111)-oriented fcc films of late transition metals such as Co and Ni. Our model indicates that the Mott-Hund's interaction results in ferromagnetic nearest-neighbor orbital correlations. Frustration associated with the mismatch between orbital and crystal symmetries prevents orbital ordering, resulting in the orbital liquid state. This state can be manifested in phenomena involving spin-orbit coupling, such as magnetic anisotropy.

The quest for topological states in hybrid nanowire devices has ignited substantial research in perfecting the nanowire-superconductor interface. Recent proposals, however, suggest that these immaculate interfaces can lead to an overly strong superconducting-semiconducting coupling that “metalizes” the nanowire (i.e., dominates its intrinsic properties which are essential for hosting topological particles). One way to reduce this coupling is to add an insulating shell between the nanowire and the superconductor. Here, we explore cadmium telluride (CdTe) shells as a tunnel barrier at the interface between indium antimonide (InSb) nanowires and a superconductor. We demonstrate the growth of epitaxial, defect-free CdTe on InSb and high-quality superconductor deposition at cryogenic temperatures, enabled by the near perfect lattice match of CdTe and InSb and their comparable thermal-expansion coefficients. Using growth and etching, we control the thickness of CdTe shells down to a few monolayers. This level of control indicates the potential of these shells to serve as a knob that modulates the coupling between a nanowire and a superconductor, possibly introducing a new generation of nanowire hybrids suitable for topological Majorana devices.

We report $abinitio$ calculations of the electronic and optical response properties of Janus-like hexagonal monolayers materials of group IV-VI. By combining phonons spectra calculations and ab initio molecular dynamics simulations, we verify that some two-dimensional (2D) group IV-VI hexagonal materials are dynamically unstable. Our results of electronic band structure based on both density functional theory (DFT) with Heyd-Scuseria-Ernzerhof hybrid functional (HSE) and ${\mathrm{G}}_0{\mathrm{W}}_0$ formalisms indicate that the dynamically stable materials exhibit indirect band gaps. The calculations clearly reveal that the hexagonal crystal structure of the group IV-VI monolayers plays a crucial role not only in determining the width of the band gap but also on the electron-hole screening effect, and consequently the strength of the exciton binding energy. Despite their strong binding, exciton binding energies in these nanomaterials are found to be in agreement with a 2D Mott-Wannier model. We also show that most of the stable 2D materials exhibit strong optical absorbance in the visible range, being promising materials for ultra-thin-film photovoltaic applications. Thus, our systematic analysis on electronic and optical properties of hexagonal monolayer materials of group IV-VI will complement forthcoming experimental measurements and can pave the way for technological applications of those materials.

Au(001) surfaces exhibit a complex reconstructed structure $\left[\mathrm{Hex}-\mathrm{Au}\left(001\right)\right]$ comprising a hexagonal surface and square bulk lattices, yielding a quasi-one-dimensional corrugated surface. When graphene was grown on this surface, the periodicity of the corrugated surface was predicted to change the electronic structure of graphene, forming bandgaps and new Dirac points. Furthermore, the graphene–Au interface is promising for bandgap generation and spin injection due to band hybridization. Here, we report the angle-resolved photoemission spectroscopy and density functional calculation of graphene on a $\mathrm{Hex}-\mathrm{Au}\left(001\right)$ surface. The crossing point of the original and replica graphene π bands showed no bandgap, suggesting that the one-dimensional potential was too small to modify the electronic structure. A bandgap of 0.2 eV was observed at the crossing point of the graphene π and Au $6sp$ bands, indicating that the bandgap is generated using hybridization of the graphene π and Au $6sp$ bands. We discussed the hybridization mechanism and concluded that the R30 configuration between graphene and Au and an isolated electronic structure of Au are essential for effective hybridization between graphene and Au. We anticipate that hybridization between graphene π and Au $6sp$ would result in spin injection into graphene.

Sc-substituted hexagonal ferrite $\mathrm{Ba}{\left({\mathrm{Fe}}_{1\text{−}x}{\mathrm{Sc}}_x\right)}_{12}{\mathrm{O}}_{19}$ has an incommensurate helimagnetic structure. However, the incommensurate helimagnetic structure has not been sufficiently determined, and the mechanism via which the helimagnetism develops has not been studied. Time-of-flight-Laue single-crystal neutron diffraction measurements were performed at 4–6 K on single-crystal samples of $\mathrm{Ba}{\left({\mathrm{Fe}}_{1\text{−}x}{\mathrm{Sc}}_x\right)}_{12}{\mathrm{O}}_{19}$ having Sc concentrations of $x=0$, 0.128, 0.153, and 0.193. The incommensurate helimagnetic structure was determined by analyzing the magnitude and direction of the ${\mathrm{Fe}}^{3+}$ magnetic moments at the five Fe1–Fe5 sites ($2a, 4e, 4f_1, 4f_2$, and $12k$). The development mechanism of the helimagnetic structure was discussed from the standpoint of superexchange interaction. The crystal structure analyses revealed that the Sc substitution enabled two significant events, namely, the coordination changes of ${\mathrm{Fe}}^{3+}$ and ${\mathrm{Sc}}^{3+}$ at the $\mathrm{Fe}2\left(4e\right)$ site, resulting in the shortened bond distances of Fe2-O1 and the preferred substitution of ${\mathrm{Fe}}^{3+}$ at the $\mathrm{Fe}4\left(4f_2\right)$ site with ${\mathrm{Sc}}^{3+}$. The magnetic structure analyses revealed that the helimagnetic structure of $\mathrm{Ba}{\left({\mathrm{Fe}}_{1\text{−}x}{\mathrm{Sc}}_x\right)}_{12}{\mathrm{O}}_{19}$ is a cone type whose base is in the $ab$ plane and height is in the $c\text{−}\mathrm{axis}$ direction. The magnetic moments of $\mathrm{Fe}2\left(4e\right), \mathrm{Fe}4\left(4f_2\right)$, and $\mathrm{Fe}5\left(12k\right)$ are aligned with distinct angles, leading to the helimagnetic structure of $\mathrm{Ba}{\left({\mathrm{Fe}}_{1\text{−}x}{\mathrm{Sc}}_x\right)}_{12}{\mathrm{O}}_{19}$, and can be explained by assuming that there is an antiferromagnetic superexchange interaction $J_5$ between $\mathrm{Fe}2\left(4e\right)$ and $\mathrm{Fe}5\left(12k\right)$ that is negligible in the $x=0$ crystal. The shorter bond distance of Fe2-O1 in Sc-rich crystals revealed by the crystal structure analyses enhances the superexchange interaction $J_5$. However, the ${\mathrm{Sc}}^{3+}$ preference for $\mathrm{Fe}4\left(4f_2\right)$ weakens $J_3$ and $J_4$. The relatively strong $J_5$ leads to competition among the three superexchange interactions, $J_3, J_4$, and $J_5$, resulting in the development of the helimagnetic structure. These findings facilitate the understanding of the essentials of the basic magnetic material $\mathrm{Ba}{\mathrm{Fe}}_{12}{\mathrm{O}}_{19}$.

Nanoscale ferroelectric topologies such as vortices, antivortices, bubble patterns, etc., are stabilized in thin films by a delicate balance of both mechanical and electrical boundary conditions. A systematic understanding of the phase stability of bubble domains, particularly when the above factors act simultaneously, remains elusive. Here we present first-principle-based simulations in combination with scanning probe microscopy of ultrathin epitaxial (001) $\mathrm{Pb}{\mathrm{Zr}}_{0.4}{\mathrm{Ti}}_{0.6}{\mathrm{O}}_3$ heterostructures to address this gap. The simulations predict that as-grown labyrinthine domains will transform to bubbles under combinations of reduced film thickness, increased mechanical pressure, and/or improved electrical screening. These topological transitions are explained by a common fundamental mechanism. Namely, we argue that, independently of the nature of the driving force, the evolution of the domain morphology allows the system to conserve its original residual depolarization field. Thereby, the latter remains pinned to a value determined by an external or built-in electric bias. To verify our predictions, we then exploit tomographic atomic force microscopy to achieve the concurrent effect of reducing film thickness and increased mechanical stimulus. The results provide a systematic understanding of phase stability and demonstrate controlled manipulation of nanoscale ferroelectric bubble domains.

Spin-chain compounds are known to exhibit fascinating magnetic properties, which mostly display magnetic ordering at very low temperatures or remain dynamic even at 0 K. In contrast, the present quasi-one-dimensional spin-chain system $\mathrm{Ba}{\mathrm{Mn}}_2{\mathrm{V}}_2{\mathrm{O}}_8$ exhibits a collinear antiferromagnetic (AFM) long-range ordering at a relatively higher temperature $T_{\mathrm{N}}\sim 37\mathrm{K}$, wherein the nearest-neighbor spins have AFM coupling along the spin chain, i.e., along the $c$ axis. The present study also reveals a short-range magnetic ordering prevailing at considerably elevated temperatures above its $T_{\mathrm{N}}$. Temperature-dependent Raman spectroscopy demonstrates an occurrence of spin-phonon coupling below $T_{\mathrm{N}}$ at least for two phonon modes, whereas the study also shows an unusual thermal evolution of the Raman modes above $T_{\mathrm{N}}$, which is apparently associated to the short-range magnetic ordering. Furthermore, extensive ab initio density functional theory calculations accompanied with classical Heisenberg model based theoretical calculations of various exchange interaction parameters $\left(J_0–J_5\right)$ suggest an AFM ground state, which matches well with the experimentally obtained spin structure.

The spin dynamics, crystalline-electric-field (CEF) level scheme, specific heat, and x-ray photoemission spectra (XPS) of ${\mathrm{Ce}}_3{\mathrm{Rh}}_4{\mathrm{Sn}}_{13}$ were investigated, which exhibits anomalous semimetal transport in the chiral crystallographic phase. CEF excitations observed at approximately 7 and 39 meV are consistent with the two inequivalent Ce-ion cites in the chiral structure. Because of broader CEF excitations and a strong $4f^1$ peak at the Fermi level in the Ce $4f$ on-resonance spectrum, the hybridized Ce $4f$ electrons contribute to the semimetal carriers. In addition, the spin fluctuation associated with the Kramers doublet ground state is characterized by the peak located at 0.15 meV. The electronic state involving the spin fluctuation causes the $T^3$ behavior of specific heat below 0.6 K, which is attributed to linear dispersion relations of electrons of the Weyl–Kondo semimetal in the chiral-lattice symmetry.

${\mathrm{Bi}}_2{\mathrm{Sr}}_2\mathrm{CaCu}{\mathrm{O}}_x$ (Bi-2212) is the only high-$T_c$ superconductor (HTS) available as a multifilamentary round wire with multiple architectures and it is a very promising conductor for the realization of high-field applications. Despite their relatively simple wire fabrication by the powder-in-tube technique, Bi-2212 wires require a tightly controlled overpressure heat treatment (HT) with a multiparameter time-temperature schedule to achieve high critical current density, $J_c$. The variation of these HT parameters, changes in the wire design, wire diameter, and powder quality can lead to variations in both the microstructure and the superconducting performance. Particularly noticeable are variations in $J_c$ performance and degree of filament bridging. In this work, we focus on the use of different magnetic characterization techniques to estimate the bridging level and assess the balance of intergrain and intragrain superconducting properties including the irreversibility field ($H_{\mathrm{irr}}$) and the pinning energy ($U_o$) in differently processed wires. Regardless of the actual bridging level, we find that the supercurrent flows at the filament bundle level, not just at the individual filament level. Moreover, using ac susceptibility we identify two distinct supercurrent contributions, one related to the intragrain and one to the intergrain properties, whose irreversibility fields are different but without large sample-to-sample variation. Moreover, an additional component of intragrain pinning mechanism becomes effective at low temperatures with positive effects also on the intergrain performance. The work clearly shows that detailed magnetic characterizations can become valuable tools to investigate the performance of differently processed Bi-2212 wires, correlating their microstructure and overall transport $J_c$, to obtain a deeper understanding of the causes of performance variation and paths to achieve further improvement.

Temperature and field-dependent neutron powder diffraction (NPD) measurements have been performed to reveal the nature of the unusual evolution of the magnetoresistance behavior with increasing Fe content in the intercalated compounds ${\mathrm{Fe}}_x{\mathrm{TiS}}_2$ (with $x=0.25,0.33,0.50,0.55$) synthesized by solid-phase reaction method with prolonged homogenization heat treatment. As derived from neutron diffraction measurements, both the ${\mathrm{Fe}}_{0.25}{\mathrm{TiS}}_2$ and the ${\mathrm{Fe}}_{0.50}{\mathrm{TiS}}_2$ compound exhibit an antiferromagnetic (AFM) order below their respective Néel temperatures $T_N\approx 52$ K and $T_N\approx 140\mathrm{K}$, which results in the presence of a large magnetoresistance accompanying the field-induced phase transition from AFM to the ferromagnetic (FM) state. At low temperatures, this AFM-FM transition is irreversible, confirmed by the irreversibility of changes in the NPD patterns and the presence of remnant magnetoresistance. In contrast, ${\mathrm{Fe}}_{0.33}{\mathrm{TiS}}_2$ shows short-range magnetic order at $T_f\approx 44$ K due to a triangular network of intercalated Fe atoms and frustrations of exchange interactions with a field-induced FM alignment of Fe magnetic moments in an applied magnetic field as revealed by NPD measurements. The field-induced transformations of the cluster glass magnetic state in this compound lead to a significant decrease in electrical resistivity. According to NPD data, a reduced impact of an external magnetic field on the electrical resistivity of the compound ${\mathrm{Fe}}_{0.55}{\mathrm{TiS}}_2$ can be ascribed to the presence of ferromagnetic or ferrimagnetic order in compounds with the Fe concentrations above $x=0.50$. The results obtained indicate that the distribution of the Fe atoms, along with their concentration in ${\mathrm{Fe}}_x{\mathrm{TiS}}_2$ layered compounds, plays a decisive role in the formation of the magnetic state and the behavior of the magnetoresistance.