M-type barium hexaferrite, BaFe 12 O 19 (BaM), is an important ferrimagnetic oxide for terahertz magneto-optical materials because of its large uniaxial magnetocrystalline anisotropy, chemically tunable high-frequency response, and strong Faraday activity. La-substituted BaFe 12 O 19 single crystals show enhanced potential for terahertz magneto-optical applications, but their practical use is still limited by severe transmission loss. Here, we investigate the origin of this loss by combining terahertz spectroscopy, defect characterization, electrical transport, and first-principles calculations. Terahertz transmission and reflection measurements reveal that transmission loss is mainly caused by bulk absorption rather than reflection. The real part of the effective dielectric constant changes only slightly, whereas the imaginary part increases markedly after La substitution. Oxygen annealing produces negligible transmission recovery, suggesting that oxygen-related defects or Fe 2+ are not the dominant origin of the loss. Positron annihilation lifetime spectroscopy reveals vacancy-type defects, accompanied by a resistivity decrease of nearly three orders of magnitude. First-principles calculations show that Fe-site vacancies produce stronger band-gap narrowing and more defect-related electronic states than La substitution alone. La-Mg co-substitution suppresses the dielectric loss, restores terahertz transmission, and maintains enhanced Faraday rotation. These results identify Fe-site-vacancy-mediated dielectric loss as the main origin of strong terahertz absorption in La-substituted BaFe 12 O 19 single crystals.

SnTe has attracted significant attention as a promising thermoelectric material due to its favorable band structure and low cost. However, its high intrinsic hole concentration and thermal conductivity still hinder further performance enhancement. In this study, a series of Sn2.9-xWxTe2.9-(In2Te3)0.03-(Cu2Te)0.18 (x = 0, 0.03, 0.06, 0.09, 0.12, 0.15) composites were synthesized by incorporating in-situ formed In2Te3 and Cu2Te nanophases along with W doping. Structural and microstructural analyses confirmed the formation of uniformly distributed nanoinclusions (10-20 nm) and homogeneous elemental distribution. W doping effectively suppressed intrinsic Sn vacancies and induced valence band convergence, while the introduction of In created resonant states. These synergistic effects significantly enhanced the Seebeck coefficient. Moreover, multiscale phonon scattering arising from nanophases, dislocations, and lattice distortions greatly reduced the lattice thermal conductivity. The sample with x = 0.09 exhibited a maximum power factor of 25.98 mu W & sdot;cm- 1 & sdot;K- 2, while the sample with x = 0.12 achieved a minimum lattice thermal conductivity of 0.406 W & sdot;m- 1 & sdot;K- 1. As a result, the optimized composition reached a peak ZT of 1.23 and an average ZT of 0.44 at 823 K, representing improvements of approximately 209 % and 215 % over pristine SnTe, respectively. These results place the material among the top-performing SnTe-based thermoelectric systems reported to date.

This paper reports a magnetically tunable U-band metallic waveguide isolator based on the ferromagnetic resonance (FMR) absorption effect. The device features a BaFe12O19 (BaM) single-crystal array integrated into a rectangular waveguide. By leveraging the high intrinsic magnetocrystalline anisotropy and narrow FMR linewidth of the single-crystal material, the isolator achieves high-frequency operation with a significantly reduced external bias field. Experimental results demonstrate a broad continuous tuning range from 50 GHz to 66 GHz. The device exhibits exceptional efficiency, with a typical insertion loss of less than 0.5 dB (minimum 0.24 dB) and an isolation exceeding 15 dB across the operating band. The cascaded array configuration ensures uniform magnetization and stable performance. This combination of ultra-low insertion loss and frequency agility makes the proposed isolator an ideal candidate for next-generation adaptive millimeter-wave communication and radar systems.

Two-dimensional nonlayered MnSe represent a unique class of nanomaterials that combine bulk structural characteristics with surface-dominated properties from unsaturated dangling bonds. However, their specific phase control remains fundamentally challenging due to inherent thermodynamic instabilities. Herein, we report the successful fabrication of ultrathin wurtzite-type and rock-salt-type MnSe nanosheets via chemical vapor deposition (CVD) by modulating growth parameters. In addition, we carried out density functional theory (DFT) and thermodynamic analysis to systematically elucidate the formation mechanisms of diverse crystalline phases during crystal growth, revealing that this polymorphic behavior stems from intrinsic thermodynamic competition. Notably, wurtzite-type MnSe exhibits unique optical properties, including a distinct photoluminescence (PL) emission feature at 900 nm (1.38 eV), caused by impurity-perturbed Mn2+ excitons. This study provides fundamental insights into phase control in nonlayered 2D materials, paving the way for their integration into electronic, optoelectronic, and spintronic devices.

Magnetocrystalline anisotropy in iron garnets originates from the interplay between lattice symmetry, cation site preference, and spin-orbit coupling mediated by oxygen. We develop a dual order parameter framework that quantitatively connects site-selective occupation of inequivalent dodecahedral (24c) sublattices to the magnetic anisotropy energy in Bi substituted yttrium iron garnet (Bi:YIG). We introduce a site-order parameter eta(so)(sublattice imbalance between alpha and beta within 24c) and a composition parameter eta(co) (total Bi fraction on 24c) and use density-functional theory across 13 representative (eta(so),eta(co)) states. K(eta(so),eta(co)) obeys a compact Landau-type expansion dominated by a large odd-in-eta(so) linear term and a weaker even-in-eta(so) curvature. The fitted map yields an analytic switching boundary K=0 in the (eta(so),eta(co)) plane and order-resolved three-dimensional surfaces and weight maps that make the hierarchy (linear >> quadratic >> cubic) explicit. This unified framework rationalizes growth-induced anisotropy trends in Bi:YIG and suggests actionable routes for engineering uniaxial anisotropy via controlled A-sublattice ordering.

Self-biased magneto-optical single-crystalline garnet materials can eliminate the need for external driving magnetic fields, significantly reducing the size of photonic integrated circuits. In this study, an (EuHoBi)3(FeGa)5O12 single-crystalline film with rectangular magnetic hysteresis loops and self-biased characteristics was successfully grown by liquid-phase epitaxy on the (GdCa)3(ZrMgGa)5O12 (SGGG) substrate. The chemical composition, magnetic properties, and MO performance of the epitaxial film were systematically investigated. One of our as-grown (EuHoBi)3(FeGa)5O12 film exhibited a coercivity of 645 ± 5 Oe, a 100% remanence ratio, and a specific Faraday rotation angle of 1180 °/cm at 1310 nm, combined with an exceptionally low optical loss of merely 0.09 ± 0.03 dB. These findings demonstrate that the epitaxial (EuHoBi)3(FeGa)5O12 single-crystalline film holds great potential for enhancing the integration density of photonic integrated circuits.

Rare-earth iron garnets are functional magnetic oxide materials whose magnetic properties are highly sensitive to cation occupation and local compositional heterogeneity. In this paper, Ga-substituted (EuHoBi)3(FeGa)5O12 single-crystalline films were fabricated by liquid phase epitaxy. Atomic-scale elemental distribution characterization and macroscopic magnetic measurements revealed nanoscale inhomogeneity in the Ga distribution, with the more inhomogeneous sample exhibiting stronger low-temperature zero-field-cooled (ZFC) and field-cooled (FC) magnetization bifurcation and a larger exchange bias field. Hysteresis-loop measurements showed a small ZFC exchange-bias-like loop asymmetry in the structurally continuous garnet films, while FC and negative field-cooled (NFC) loops further showed that the magnitude and direction of the loop shift could be modulated by the cooling field. The absence of an obvious frequency-dependent peak shift in alternating-current susceptibility suggested that a conventional spin-glass transition was unlikely to dominate the low-temperature irreversibility within the measured frequency window. Considering the compositional inhomogeneity and the cooling-history-dependent loop shift together, the observations were interpreted within a microstructure-related framework involving weakly compensated antiferromagnetic-like local regions coupled to a long-range ferrimagnetic matrix. Here, “antiferromagnetic-like” is used as a phenomenological descriptor for regions with a reduced net ferrimagnetic moment and possible short-range antiparallel spin correlations, rather than as evidence for a directly identified long-range antiferromagnetic phase. A conceptual two-dimensional Ising-type Monte Carlo model further suggested that pinned internal interfaces between antiferromagnetic-like regions and the ferrimagnetic matrix could qualitatively generate exchange-bias-like loop shifts. These findings indicate a correlation among nanoscale cation-distribution inhomogeneity, local magnetic heterogeneity, and low-temperature exchange-bias-like behavior in Ga-substituted iron-garnet epitaxial films, highlighting the potential role of internal compositional and magnetic interfaces in tuning the magnetic responses of complex oxide materials.

Rare-earth iron garnets are functional magnetic oxide materials whose magnetic properties are highly sensitive to cation occupation and local compositional heterogeneity. In this paper, high-quality Ga-substituted (EuHoBi)3(FeGa)5O12 single-crystalline films were fabricated by liquid phase epitaxy (LPE). Atomic-scale elemental distribution characterization and macroscopic magnetic measurements revealed nanoscale inhomogeneity in the Ga distribution, with the more inhomogeneous sample exhibiting stronger low-temperature zero-field-cooled (ZFC) and field-cooled (FC) magnetization bifurcation and a larger exchange bias field. Hysteresis-loop measurements showed that a finite horizontal loop shift was already present after ZFC, suggesting a spontaneous intrinsic exchange bias (IEB) in the structurally continuous garnet films. FC and negative field-cooled (NFC) loops further showed that the magnitude and direction of IEB can be modulated by the cooling field. Frequency-independent alternating-current susceptibility indicated that IEB was not dominated by a conventional spin-glass state. Instead, the results were consistent with a microstructure-related mechanism in which antiferromagnetic-like short-range regions embedded in a long-range ferrimagnetic matrix, which provided internal pinning interfaces at low temperature. A conceptual two-dimensional (2D) Ising-type Monte Carlo model further suggested that pinned internal interfaces between antiferromagnetic-like regions and the ferrimagnetic matrix can generate a tunable IEB. These findings establish a correlation among nanoscale cation-distribution inhomogeneity, local magnetic heterogeneity and low-temperature exchange bias in Ga-substituted iron-garnet epitaxial films, providing a potential strategy for tailoring magnetic responses in complex oxide materials.

Phosphorus, a crucial yet nonrenewable resource, is essential for agriculture, life processes, and various industries. In this study, we employed co-pyrolysis of eggshells and peanut shells to prepare calcium-based biochar (EPB) with a high adsorption capacity and ecological non-toxicity, enabling effective phosphorus recovery from wastewater. EPB was characterized via X-ray diffraction, scanning electron microscopy, electron probe microanalysis, and Brunauer–Emmett–Teller analysis. Additionally, its phosphate adsorption characteristics were investigated under varying temperature, pH, and coexisting ion conditions. Phosphate adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 178.08 mg/g, and the kinetics aligned with those of the quasi-second-order kinetic model. Phosphate adsorption by EPB was driven by electrostatic attraction and chemical precipitation. Moreover, we investigated the effects of phosphorus-enriched biochar on the growth and development of tobacco and soil microbial communities. Phosphorus-enriched biochar increased organic and inorganic phosphorus levels and promoted tobacco growth compared with conventional fertilizers. Phosphorus-enriched biochar reshaped tobacco rhizosphere microbial communities, promoting beneficial taxa, such as Nitrospira. Structural equation analysis showed that EPB enhanced microbial alpha diversity and key microbial communities, improving phosphorus availability and tobacco growth and development. Conclusively, this study provides a theoretical reference for phosphorus-containing wastewater treatment and reuse.

In order to investigate the factors affecting the bonding of third-generation semiconductor materials SiC and III-V compounds InP, different pretreatment steps are implemented on SiC and InP wafer substrates to explore the methods to realize the successful bonding of SiC/InP and to improve its bonding strength. In the wide application of wafer bonding technology, plasma plays an indispensable role by reducing the process temperature. Although many studies on plasma-assisted direct wafer bonding have been reported, in-depth studies on the plasma itself are still insufficient. The existing literature mainly focuses on the optimization of the parameters of plasma surface treatment, while the studies on the surface cleaning steps before and after plasma activation and the annealing process, which need to be comprehensively investigated to maximize the bond strength, are still incomplete. In particular, ultrasonic cleaning as a pretreatment step and its application before plasma activation on the bonding effect deserve in-depth study. In this study, we evaluate the various process steps of SiC/InP wafer bonding through specific experimental studies. The focus is on the effect of ultrasonic cleaning on bond strength, while the parameters of plasma surface treatment and low-temperature annealing conditions are optimized. The experimental results show that ultrasonic cleaning is a key part of its bonding success, and that the selection of the appropriate plasma gas, the adjustment of the instrumental power, and the processing time all have an impact on the bonding effect of the final wafer pair.

The Magneto-Optical Kerr Effect (MOKE) is a fundamental tool in magnetometry, pivotal for advancing research in optics, magnetism, and spintronics as a direct probe of magnetization. Traditional MOKE measurements primarily detect the magnetization components parallel to the Poynting vector, which can only access the magnitude but not the direction of the orthogonal component. In this study, we introduce an orthogonal MOKE geometry in which the Kerr signal detects both the magnitude and direction of the magnetization component perpendicular to the Poynting vector. We demonstrate the broad applicability of this orthogonal geometry through the MOKE measurements in cubic ferromagnets and van der Waals ferromagnet. We theoretically show that the orthogonal MOKE geometry is enabled by the multipolar structure of Berry curvature in the magnetization space, which generally induces a Voigt vector orthogonal to the magnetization, thereby accounting for the unique magnetization angle dependence distinct from conventional MOKE. The establishment of the orthogonal MOKE geometry not only introduces a new paradigm for magneto-optical measurements but also provides a framework for exploring the magnetization multipoles of Berry curvature across the electromagnetic spectrum.

The delicate design of bifunctional catalysts for the decontamination of combined pollution has become a hotspot but the functional mechanism remains unclear. In this work, we constructed Fe foam supported ZnIn2S4 (FZIS) composites for synchronously removing phosphorus (P) and organic contaminants. The composites act both as iron source for the phosphate removal and photocatalysts for the oxidation of refractory organic contaminants (amoxicillin, quinolone antibiotics, dyes). The performance was highly dependent on the relative ratios of P and organic pollutants. The optimal photocatalysts (FZIS-2) showed 94.5 % amoxicillin (AMX) and 71.4 % P removal from combined pollution(n(P)/n(AMX) = 5:1) water after 1h reaction under visible light irradiation. Experimental tests and characterization demonstrated the synergistic interaction of Fe foam and ZnIn2S4 for contaminants removal. The production of •OH by the inner-generate H2O2 under the activation of leached iron ions enhanced the degradation of AMX. Meanwhile, the photocatalysis enhanced iron leaching of Fe foam, promoting the precipitation of phosphate with ferric species. The migration and transformation process of organic pollutants on the catalyst surface and the spatial distribution of phosphate were figured out. Furthermore, the performance for the actual effluent treatment using FZIS-based composites was investigated. The work unravels the synergistic effects of Fe foam and the supported photocatalytic components for the decontamination of multiple pollutants and provides new thoughts for combined pollution abatement.

The microstructure geometry and self-assembly mechanism of the (TbBi) 3 FeO 5 O 12 -based melts were revealed at the ion cluster level. This work is conducive to regulating the performance of ReIGs using the melt structure.

Excess intrinsic Ge vacancies in GeTe materials lead to excessively high hole concentration and high thermal conductivity, producing poor thermoelectric performance. Here, synergistic control and optimization of the thermoelectric transport properties and microstructure of GeTe-based materials were achieved through co-doping with In and rare earth element Y, resulting in a significant enhancement of thermoelectric performance. The Ge0.94In0.03Y0.03Te sample reached a ZTmax of 1.84 at 773 K, representing an increase of around 91% compared to the GeTe matrix. The experimental results indicate that the doping of In optimizes the band structure by introducing resonant levels and increasing the degeneracy of the valence band. Y doping introduces in situ nanoscale secondary phases and lattice distortions due to defect generation, enhancing phonon scattering and significantly reducing the κlat. This work elaborates on how co-doping with In and Y achieves the optimization of the thermoelectric performance of GeTe-based materials. While the electrical transmission characteristics are improved, the thermal conductivity is significantly reduced. For the Ge0.94In0.03Y0.03Te sample, κlat decreased to ∼0.56 W m-1 K-1 at 573 K, resulting in a ZTave of ∼0.99 over the entire temperature range, representing over 140% improvement compared to undoped GeTe. This improvement is significantly higher compared with other works on GeTe and PbTe.

To study the effect of large area uniform garnet film on the consistency of image quality of a magneto-optical imaging system, the effect of lattice mismatch on a large area uniform domain structure of magneto-optical materials was studied. In this paper, (BiTm)(3)(GaFe)(5)O-12 thin garnet films with different stress were prepared on the surface of gadolinium gallium garnet by liquid phase epitaxy. The results show that the magnetic hysteresis mechanism exists in the (BiTm)(3)(GaFe)(5)O-12 thin films with tensile stress, and the domains can preferentially respond to magnetic signals in very small regions. This is mainly the phenomenon of magnetic domain partitioning caused by cracks. In addition, the non-uniform distribution of coercive force in a large range is the main cause of hysteresis. The thin films with weak compressive stress (BiTm)(3)(GaFe)(5)O-12 are uniformly distributed over a large area.

The Ⅳ-Ⅵ compound GeTe is considered as a promising alternative to the toxic PbTe for high-efficiency mid-temperature thermoelectric applications.However,pristine GeTe suffers from a high concentration of Ge vacancies,resulting in an excessively high hole concentration(＞ 1 × 10 21 cm -3 ),which greatly limits its thermoelectric enhancement.To address this issue,CuBiTe 2 alloying is introduced to increase the formation energy of Ge vacancies in GeTe,thereby inhibiting the high carrier concentration.The carrier scattering caused by the electronegativity difference between different elements is suppressed due to the similar electronegativity of Cu and Ge atoms.A relatively high hole mobility is obtained,which ultimately leads to a high power factor.Additionally,by introducing Se as an alloying element at the anionic site in GeTe,dense point defects with mass/strainfield fluctuations are induced.This contributes to the strengthening of phonon scattering,thereby reducing the lattice thermal conductivity from 1.44 W·m -1 ·K -1 for pristine GeTe to 0.28 W·m -1 ·K -1 for Ge 0.95 Cu 0.05 Bi 0.05 Te 0.9 Se 0.15 compound at 623 K.

M-type barium hexaferrites (Ba 1-x La x Fe 12 O 19 ) were prepared by the liquid phase epitaxial (LPE) method, in which Ba 2+ was substituted by La 3+ . The Faraday rotation effect of materials in the frequency range of 0.5–0.8 terahertz (THz) is studied by THz time-domain spectroscopy (THz-TDS). It was demonstrated that the M-type barium hexaferrites have a large Faraday rotation angle, and the Faraday rotation angle can be further enhanced by the substitution of La 3+ . For 500 µm thick film samples, the Faraday rotation angle exceeded 20° under the maximum measuring magnetic field of 400 mT. Moreover, the Faraday rotation angle is not saturated, and it will further increase with the increase of the magnetic field. At 0.8 THz, the Faraday rotation angle of the sample with x = 0 is 21.48°, for x = 0.05 which is 21.62°, and for x = 0.19 which is 28.38°. The Faraday rotation angle is enhanced by about 32%. By measuring the magnetic properties of the material, we found that the fundamental cause of the enhancement in the Faraday rotation angle lies in the increased saturation magnetization of the material after La 3+ substitution. In the experiment, it was also found that the transmittance of the material to the THz wave decreased sharply with the increase of La substitution. For sample x = 0, the transmittance is as high as 60%. When the substitution amount of La is only x = 0.05, the transmittance decreases to about 55%. When the maximum substitution amount of La is x = 0.24, the transmittance of the material is only about 2%.

Magneto-optical garnet shows great potential in integrated optical isolators due to its highly efficient non-reciprocity. In this work, we prepared magneto-optical lithium-modified terbium bismuth iron garnet films using the liquid phase epitaxy method and systemically investigated the effect of lithium modification on magnetic properties. We found a trace amount of lithium modification induced in-plane magnetization and a minimum in-plane driving field around 2 Oe. Meanwhile, high remanence over 70% was obtained in tensile-strain samples. Most importantly, in comparison to unmodified samples, the calculation of anisotropy demonstrated the giant reduction of growth-induced anisotropy in the Li: TbBiIG up to 105erg/cm3. It reveals a new rule of ions’ preferred occupation in dodecahedral sublattices indirectly. This permits Furthermore, enhanced Faraday rotation in the near-infrared band was confirmed in the samples about 1 micrometer, up to 48% higher than unmodified samples. Our work shows Li:TbBiIGs enable a prime candidate material with substantial potential for integrated optical isolation applications.

In-plane easily magnetized scandium substituted thulium iron garnet films(Tm3Fe5-xScxO12) with soft magnetic properties have recently attracted attention for fluxgate magnetometer applications. In this paper, thin Tm3Fe5-xScxO12 films were prepared on gadolinium gallium garnet substrates by liquid phase epitaxial(LPE) method. Microstructural properties, composition, magnetic properties and the in-plane anisotropy of the films were discussed. We found that the films turned from tensile stress to compressive stress as the Sc3+ substitution decreased, and the in-plane anisotropy was mainly caused by stress reducing as Sc3+ declined. By analyzing the in-plane magnetic hysteresis loops, the magnetic performance was the best when x = 0.75. Tm3Fe4.25Sc0.75O12 film had the lowest in-plane coercive field(0.006 Oe) and the highest initial magnetic permeability(3 7 8), which was more beneficial to realize fluxgate magnetometers.