Abstract:

A recent theoretical study of CsMnF₄ under pressure [Inorg. Chem. 2024, 63(29), 13231] presents conclusions on its structural, optical, and magnetic behavior that conflict with established experimental evidence. Crucially, this work omits key prior experimental results on CsMnF₄ and related Mn³⁺ fluorides under pressure. This perspective examines the resulting discrepancies, arguing that the omissions of this data undermines the theoretical estimates and methodological validity of Ref. [1]. This paper provides a critical overview centered on two main points: the contested nature of the pressure-induced high-spin to low-spin transition observed in CsMnF₄ at ~37 GPa and a detailed discussion of Jahn-Teller physics in this archetypal system. By reconciling the existing literature with the new theoretical claims, this work aims to clarify the high-pressure behavior of CsMnF₄.

Abstract: Boron incorporation in gallium nitride (GaN) semiconductors affects their physical properties, such as the bandgap and lattice parameters. However, the macroscopic electrical behavior of BGaN remains largely unexplored. In this study, Mg-doped p-type BGaN epitaxial layers were grown by metal–organic chemical vapor deposition (MOCVD) and characterized using Hall effect and van der Pauw measurements over a temperature range from liquid nitrogen temperature up to 277°C. The results reveal a monotonic dependence of conductivity on temperature, consistent with nearest-neighbor hopping (NNH) conduction, quite similar to that observed in Mg-doped GaN. Unlike in BGaN, the transition between NNH and free-carrier conductivity occurs at a higher temperature, which is attributed to a higher defect concentration. These findings provide new insight into how boron incorporation influences the electronic properties of gallium nitride–based materials and offer valuable guidance for future electronic and optoelectronic applications.

Abstract: Electrochemical biosensors are becoming increasingly prevalent across medical, food, and bioprocessing industries for monitoring complex biological processes. However, their sensitivity to contamination and exposure to potentially hazardous biological species often necessitates single-use disposal, contributing to the release of high-value, high-demand, and environmentally damaging materials into the environment. This study investigates the feasibility of a closed-loop recycling process for single-use glu-cose biosensors, with a focus on the recovery and reuse of noble metals silver and gold. Guided by ecodesign principles and using low impact materials we developed a silver screen ink, gold syringe ink, and a poly(lactic acid) (PLA) substrate. Sensors were fab-ricated by additive manufacturing and screen printing - enabling the scalability afforded by screen printing to produce the high coverage silver layer, while also minimising gold ink waste using additive manufacturing. A low-energy recovery method that exploited selective solvent compatibility was developed to reclaim silver and gold. Sec-ond-generation devices were then fabricated, demonstrating performance comparable to commercial equivalents while achieving an 80% reduction in material usage, cost, and environmental impact across 15 categories using life cycle assessment (LCA).

Abstract: Since the first successful synthesis of borophene in 2015, this atomically thin boron allotrope has attracted extensive attention due to its polymorphic structures, metallic conductivity, and outstanding mechanical flexibility. As a new member of the two-dimensional (2D) materials family, borophene exhibits a unique triangular lattice with tunable hexagonal vacancies, leading to rich structural diversity and anisotropic physical properties. Recent breakthroughs in synthesis—particularly molecular beam epitaxy (MBE), chemical vapor deposition (CVD), and solvothermal-assisted liquid-phase exfoliation (S-LPE)—have significantly expanded the accessible structural phases and improved control over film quality and stability. Meanwhile, borophene’s distinctive combination of structural and electronic characteristics has enabled its rapid development in both energy and biomedical applications. In energy storage, borophene serves as a promising anode material for lithium/sodium-ion batteries and a lightweight medium for hydrogen storage and supercapacitors, owing to its metallic conductivity, high surface charge density, and large adsorption capacity. In biomedicine, borophene-based nanoplatforms exhibit excellent photothermal conversion efficiency, enabling multifunctional roles in cancer diagnosis and therapy. Despite these advances, several challenges—such as environmental instability, oxidation susceptibility, and limited scalable synthesis—continue to restrict practical implementation. Future progress will depend on chemical functionalization, surface passivation, and machine-learning-assisted materials design to achieve oxidation-resistant, large-area, and biocompatible borophene derivatives. This review summarizes recent advances in borophene synthesis, structural engineering, and multifunctional applications, while outlining key scientific challenges and future opportunities for the realization of borophene-based materials in next-generation energy and biomedical systems.

Abstract: The current study explored the martensite structures of Fe₃Pt alloys, specifically Cmmm-Fe₃Pt, P63/mmc-Fe₃Pt, P4/mmm-Fe₃Pt, and R\( \overline{3} \)m-Fe₃Pt, aiming to provide a comprehensive understanding of the mechanisms that govern their physical and chemical properties. We have focused on their structural, thermodynamical, magnetic, electronic, and mechanical characteristics, utilizing the Density Functional Theory (DFT) technique. Our study revealed that in addition to the previously reported austenitic cubic Pm\( \overline{3} \)m-Fe₃Pt and martensite tetragonal I4/mmm-Fe₃Pt with L1₂ structure, there exist additional Fe₃Pt phases that exhibit excellent structural, thermodynamic, magnetic and mechanical properties. The calculated enthalpies of formation were found to be negative and less than -0.39 eV in all the structures considered, indicating thermodynamic stability and formation under experimental synthetic conditions. Moreover, the computed magnetic moments are in the range 2.94 to 3.04 μ_B, which is relatively comparable to 3.24 μ_B of the widely reported Pm\( \overline{3} \)m-Fe₃Pt alloy. The analysis of the electronic structure also revealed strong magnetism due to the presence of asymmetry in the spin up and down states of the density of states (DOS) plots. To determine the mechanical response of Fe₃Pt structures under loading conditions, we computed the independent elastic constants, macroscopic properties and stress-strain relationship under hydrostatic stress. All four phases, but the hypothetical P63/mmc-Fe₃Pt showed excellent mechanical stability at ambient conditions and exceptional hardness and resistance to compression in the elastic region 0% ≤ strain ≤ 10%. This evidence is provided by satisfying the Born necessary stability conditions, large bulk modulus and a strong linear relationship fit (R²) of greater than 0.94.

Abstract:

Electron transport measurements on Co/TiN multilayers are employed to explore the effect of TiN layers on the Co resistivity. 50-nm-thick multilayer stacks containing N = 1-10 individual Co layers that are separated by 1-nm-thick TiN layers are sputter deposited on SiO₂/Si(001) substrates at 400 °C. X-ray diffraction and reflectivity measurements indicate a tendency for a 0001 preferred orientation, an x-ray coherence length of 13 nm that is nearly independent of N, and an interfacial roughness that increases with N. The in-plane multilayer resistivity ρ increases with increasing N = 1-10, from ρ = 14.4 to 36.6 µΩ-cm at room temperature and from ρ = 11.2 to 19.4 µΩ-cm at 77 K. This increase is due to a combination of increased electron scattering at interfaces and grain boundaries, as quantified using a combined Fuchs-Sondheimer and Mayadas-Shatzkes model. The analysis indicates that a decreasing thickness of the individual Co layers d_Co from 50 to 5 nm causes not only an increasing resistivity contribution from Co/TiN interface scattering (from 9 to 88% with respect to the room temperature bulk resistivity), but also an increasing (39 to 154%) grain boundary scattering contribution which exacerbates the resistivity penalty due to the TiN liner. These results are supported by Co/TiN bilayer and trilayer structures deposited on Al₂O₃ (0001) at 600 °C. Interfacial intermixing causes Co₂Ti and Co₃Ti alloy phase formation, an increase in the contact resistance, a degradation of the Co crystalline quality, and a 2.3× higher resistivity for Co deposited on TiN than Co directly deposited on Al₂O₃(0001). The overall results show that TiN liners cause a dramatic increase in Co interconnects due to diffuse surface scattering, interfacial intermixing/roughness, and Co grain renucleation at Co/TiN interfaces.

Abstract: An investigation into the influence of annealing time on structural ordering of Poly-3-Hexylthiophene has been performed via analyses of absorbance data on the premise that ordering status is reflected on the optoelectronic properties. Thin films heated from 0 to 100 minutes were examined. It was found that 20 minutes annealing yields a thin film with highest structural ordering, with density of states of 5.76×1038 m-3 kg-1 and carrier density of 5.24×108 m-3. Samples annealed beyond 40 minutes exhibited a balanced presence of ordered and disordered phases. The results demonstrated that during thermal treatment at a fixed temperature, the structural ordering and conformity continuously change with time, affecting the optoelectronic properties; thus, emphasizing the necessity of “time-profile” to determine the appropriate annealing time for a specific application of the polymer.

Abstract: In this work, a novel biomass derived carbon dots (CDs) with superior fluorescent properties were prepared by tomato straws. The selective, eco-friendly sensor for the detection of tetracycline (TC) was developed by grafting SiO2 molecular imprinted polymers onto the surface of CDs (CDs@SiO2-MIPs). This sensor combined the high selective adsorption property with the sensitivity of fluorescence detection, which sensing mechanism stems from the off fluorescent signal after the molecular imprinting specifically recognizing the target substance. Under optimal conditions, the fluorescence intensity of the sensor decreased linearly with increasing the concentration of TC from 1.00×10-7 to 5.00×10-4 mol/L. The detection limit of TC was 9.33 ×10-8 mol/L. This work provides a novel biomass derived CDs and a simple molecularly imprinted fluorescence sensing method for the detection of environmental organic pollutants.

Abstract: The synthesis of bismuth(III) sulphide thin films on various textiles is of interest due to their potential applications in flexible solar absorber coatings and thin-film solar cells. These thin films were formed simultaneously on textiles of different compositions and morphologies using the environmentally friendly, low-cost successive ionic layer adsorption and reaction (SILAR) method at ambient temperature. The deposited films were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy. This paper discusses how the structure and composition of the textiles affect the phase and elemental composition, crystallinity, morphology and optical properties of the formed films. The properties of the films are then compared. Depending on the textiles used, the formed films can be amorphous or semi-crystalline, and can be rich in sulphur or near to stoichiometric. Accordingly, the normalised atomic percentages of Bi in the films range from 3.62% to 33.87%, and those of S range from 96.38% to 66.13%. The energy band gap value of the composites also varies depending on the textile substrate, ranging from Eg = 1.58 eV to Eg = 1.8 eV. These properties directly impact the films' applications.

Abstract: This study presents the electrical and optical properties of phosphate glasses in the 35P2O5 -xV2O5 -(65–x) Sb2O3 (PVS) system with 0 ≤ x ≤ 65 mol%. DC resistivity was measured using the Van der Pauw method and optical absorption spectra were recorded in the UV–VIS–NIR range. Electrical transport is attributed to simultaneous hopping of small polarons (SPs) between V4+ and V5+ (vanadium ion) sites and small bipolarons (SBPs) between Sb3+ and Sb5+ (antimony ion) sites. The resistivity exhibits a non- linear dependence on the ionic fraction of vanadium, defined as, [V]([V]+[Sb]) where [V] and [Sb] are the concentrations of the respective cations in the glasses. Whereas the resistivity exhibits a minimum in the composition range 0 ≤ nV ≤ 0.3, a resistivity maximum was observed in the range 0.3 ≤ nV ≤ 0.5. On further increasing nv, the resistivity exhibits a monotonic decline. In the composition range 0 ≤ nV ≤ 0.3, where the hopping distance between V ions decreases, while that between the Sb ions increases, the resistivity minimum has been shown to be the consequence of decreasing tunneling distance of SPs between the V4+ and V5+ ion sites. Though the probability of successful hops of SBPs decreases on account of increasing separation between Sb3+ and Sb5+ ions, the far superior mobility of SPs than that of SBPs more than offsets the decreasing contribution of SBPs to the total conductivity. In the composition range 0.3 ≤ nV ≤ 0.5, the resistivity, activation energy for DC conduction, glass transition temperature and also density exhibit their respective maxima even though the separation between V4+ and V5+ sites continues to decrease. This feature is explained by enhanced localization of electrons on account of increased disorder (entropy) among the SPs and SBPs, similar to that of Anderson localization. This argument is further supported by a shift of the polaronic optical absorption bands associated with the SPs and SBPs toward higher energies. The transport behavior of all the glasses except the x = 0 composition has been explained by adiabatic transport, principally, by the SPs on V ions while the Sb ions contribute little to the total transport process. On the contrary, Sb ions is the principal source that produces the highly disordered potential field leading to a resistivity maximum at a [V/Sb] ratio of ~ 0.5 in the glass composition.

Abstract: Heusler metamagnetic shape memory alloys (MMSMAs) show a large functional response associated with a first order martensitic transformation (MT). The strong magneto-structural coupling together with mixed magnetic interactions enable controlling this MT by means of magnetic field resulting in different multifunctional properties such as giant magnetoresistance, metamagnetic shape-memory effect (MMSM), or inverse magnetocaloric effect (MCE). Both the shift rate of MT as a function of the magnetic field and its eventual suppression are key parameters for the development of all these effects. In this work we present our findings regarding the use of strong steady magnetic fields, up to 33 T, to study in detail the magnetic field induced MT and its suppression in MnNi(Fe)Sn MMSMAs, leading to creation of the T-0H phase diagrams of the MT. Moreover, we have analyzed the impact of Fe - doping and, as direct consequence, the magnetic coupling on the suppression of the magnetostructural transformation.

Abstract: Magnetic tunnel junctions (MTJs) are pivotal for spintronic applications such as magnetoresistive memory and sensors. Two-dimensional van der Waals heterostructures offer a promising platform for miniaturizing MTJs while enabling twist-angle engineering of their properties. Here, we investigate the impact of twisting the insulating barrier layer on the performance of a van der Waals MTJ with the structure graphene/1T-VSe₂/h-BN/1T-VSe₂/graphene, where 1T-VSe₂ serves as the ferromagnetic electrodes and monolayer h-BN acts as the tunnel barrier. Using first-principles calculations based on density functional theory (DFT) combined with the non-equilibrium Green’s function (NEGF) formalism, we systematically calculate the spin-dependent transport properties for 18 distinct rotational alignments of the h-BN layer (0° to 172.4°). Our results reveal that the tunneling magnetoresistance (TMR) ratio exhibits dramatic, rotation-dependent variations, ranging from 2328% to 24608%. The maximum TMR occurs near 52.4°. Analysis shows that the twist angle modifies the d-orbital electronic states of interfacial V atoms in the 1T-VSe₂ layers and alters the spin polarization at the Fermi level, thereby governing the spin-dependent transmission through the barrier. This demonstrates that rotational manipulation of the h-BN layer provides an effective means to engineer the TMR and performance of van der Waals MTJs.

Abstract: This study aims to investigate the vibrational, structural, morphological, optical and magnetic properties of Zn1-xCoxO with 0.00x0.05, prepared by sol-gel method via amorphous citrate precursor. FTIR spectroscopy has been used to follow the mecha-nism of thermal decomposition process of ZnO precursor. XRD and FTIR-ATR tech-niques showed only the single wurtzite crystalline phase with the presence of oxygen deficiency and/or vacancies, and secondary phases were not detected. SEM micro-graphs shown agglomerated particles of irregular shape and size with a high distribu-tion, evidenced particles of nanometric size with a morphology change for x=0.05. We detected high spin Co2+ ions located in tetrahedral core and pseudo-octahedral surface sites, substituting Zn2+ ions. The energy band gap of the ZnO semiconductor decreases gradually by increasing the Co doping concentration. M vs H for undoped ZnO nano-particles exhibited a diamagnetic overlapped with a weak ferromagnetic signal at room temperature. Interestingly, temperature dependent magnetization showed a su-perparamagnetic behavior with a blocked state in the low temperature range. The Co doped ZnO samples evidenced a weak ferromagnetic signal and a paramagnetic com-ponent, which increased with x. The saturation magnetization increased until x=0.03 and then decreased for x=0.05, while the coercive field gradually decreased.

Abstract: This study explores the impact of thermal annealing on the magnetic signal enhancement of three distinct Metglas ribbon materials: 2826MB3, 2605SA1, and 2714A. Each material underwent a systematic annealing process under a range of temperatures (50-500 oC) and durations (10-60 min) to evaluate the influence of thermal treatment on their magnetoelastic performance. The experimental setup applied a constant excitation frequency of 20 kHz, allowing for direct comparison under identical measurement conditions. Results show that while all three alloys benefit from annealing, their responses differ in magnitude, stability, and sensitivity. The 2826MB3 and 2605SA1 ribbons exhibited similar enhancement patterns, with maximum normalized voltage increases of 75.8% and approximately 70%, respectively. However, 2605SA1 displayed a more abrupt signal drop at elevated temperatures, suggesting reduced thermal stability. In contrast, 2714A reached the highest enhancement at 86.8%, but also demonstrated extreme sensitivity to over-annealing, losing its magnetic response rapidly at higher temperatures. The findings highlight the critical role of carefully optimized annealing parameters in maximizing sensor performance and offer practical guidance for the development of advanced magnetoelastic sensing systems.

Abstract: This report is on Co- and Ti-substituted M-type barium and strontium hexagonal ferrites that are reported to be single phase multiferroics due to transition from Neel type ferrimagnetic order to a spiral spin structure that is accompanied by a ferroelectric polarization in an applied magnetic field. The focus here is the nature of magnetoelectric (ME) interactions in bilayers of ferroelectric PZT and Co- and Ti-substituted BaM and SrM. The ME coupling in the ferrite-PZT bilayers arise due to the transfer of magnetostriction induced mechanical deformation in a magnetic field in the ferrite resulting in an induced electric field in PZT. Polycrystalline Co and Ti doped ferrites, Ba (CoTi)x Fe12-2xO19, (BCTx), and Sr (CoTi)x Fe12-2xO19 (SCTx) (x = 0-4) were found to be free of impurity phases free all x-values except for SCTx that had a small amount of α-Fe2O3 in the x-ray diffraction patterns for x ≤ 2.0. The magnetostriction for the ferrites increased with applied filed H to a maximum value of around 2 to 6 ppm for H ~ 5 kOe. BCTx/SCTx samples showed ferromagnetic resonance (FMR) for x = 1.5 - 2.0 and the estimated anisotropy field was on the order of 5 kOe. The magnetization increased with the amount of Co and Ti doping and it decreased rapidly with x for x > 1.0. Measurements of ME coupling strengths were done on bilayers of BCTx/SCTx platelets bonded to PZT. The bilayer was subjected to an AC and DC magnetic field H and the magnetoelectric voltage coefficient (MEVC) was measured as a function of H and frequency of the AC field. For BCTx-PZT the maximum value of MEVC at low-frequency was ~5 mV/cm Oe and a 40-fold increase at electromechanical resonance (EMR). SCTx-PZT composites also showed a similar behavior with the highest MEVC value of ~14 mV/cm Oe at low frequencies and ~200 mV/cm Oe at EMR. All the bilayers showed ME coupling for zero magnetic bias due to the magneto-crystalline anisotropy field in the ferrite that provided a built-in bias field.

Abstract: This study utilized SCAPS-1D solar simulation software to model how different hole transport layers (HTLs) affect the photoelectric conversion efficiency (PCE) of CsPbI₂Br perovskite solar cells under indoor low-light conditions. Simulation parameters include 300 K working temperature, white LED light source with 560 lux illuminance, 5700 K color temperature, equivalent to 0.661 mW/cm² power density. The investigation explores the influence of layer thickness and defect concentration on performance to identify optimal parameters. Simulation results revealed that among eight hole transport materials (CuSCN, Cu₂O, CuI, NiO, MoS₂, PTAA, P3HT, Spiro-OMeTAD), CuI achieved the best performance with open-circuit voltage (Voc) of 1.22 V, short-circuit current density (Jsc) of 0.153 mA/cm², fill factor (FF) of 83.84%, and PCE of 23.66%. Analysis of HTL and absorption layer thickness, bulk defect concentration, interface defect density, and HTL-free scenario showed that interface defect concentration and absorption layer parameters have greater influence than HTL thickness. Under optimized conditions of 0.87 μm absorption layer thickness, defect concentration of 10¹⁵ cm⁻³, and interface defect concentration of 10⁹ cm⁻³, PCE reached 26.13%, while the HTL-free structure achieved 19.57%. This study demonstrates that CuI as HTL provides excellent efficiency for CsPbI₂Br perovskite solar cells and highlights their potential in indoor low-light power generation applications.

Abstract: Titanium dioxide can be employed in different photocatalytic and solar energy conversion applications due to its abundance, non-toxicity, and chemical stability. Undoped and Cu-doped TiO2 powders were synthesized using the powder method. The characteristics of the prepared photocatalysts-material were determined by XRD, SEM, absorbance and chemical analysis. XRD analysis showed the formation of TiO2 in its anatase and rutile phases. Sphere-like shapes with sizes of 100 nm were inferred from SEM images. The photocatalytic tests revealed that the Cu-doped TiO2 nanoparticles exhibited high photocatalytic activity in degrading contaminated water. This enhancement can be attributed to the formation of oxygen vacancies, which promote the photodegradation of organic compounds.

Abstract: This study employs DFT+U calculations to investigate the ferromagnetic properties of ErAl2 and ErNi2 Laves phases under an external hydrostatic pressure P (0 GPa ≤ P ≤ 1.0 GPa). The calculated magnetic moments per formula unit for both crystalline structures align with experimentally reported values: 4.40 μB/f.u. in the hard magnetization < 001> axis for ErAl2 and 5.56 μB/f.u. in the easy magnetization < 001> axis for ErNi2. The DFT results indicate that the magnetic moment remains unchanged up to 1 GPa of hydrostatic pressure, with no structural instabilities observed, as evidenced by a nearly constant formation energy for ErAl2 and ErNi2 alloys. The simulations confirm that the magnetic behavior of ErAl2 is primarily driven by the electrons localized in the f orbitals. In contrast, for ErNi2, both d and f orbitals significantly contribute to the total magnetic moment. Finally, the electronic specific heat coefficient was calculated and reported as a function of hydrostatic pressure up to P = 1.0 GPa for each Laves phase.

Abstract: This study presents a compact gamma-ray detector based on all-inorganic halide perovskite CsPbBr₃, targeting high energy resolution and low-cost fabrication for nuclear security applications. The active layer was prepared via solution-based spin-coating, combined with surface passivation and multidimensional heterojunction engineering to enhance the carrier mobility–lifetime product (μτ) to 10^-3 cm²/V. The optimized device achieved an energy resolution of 4.3% at 662 keV (FWHM), approaching the performance of CdZnTe detectors while reducing fabrication cost by over 70%. A convolutional neural network (CNN) was further integrated for energy spectrum deconvolution and source classification, enabling millisecond-level response and accurate identification. The final system features low power consumption (<100 mW), miniaturized packaging, and robust environmental stability, making it suitable for real-time deployment in field scenarios such as customs inspection and radiological emergency response.

Abstract: The thermal behavior of a three-layer structure – glass/ITO/TAPC/CBP/BPhen – in an OLED system was investigated using in situ spectroscopic ellipsometry during controlled heating from room temperature to 120°C over 60 minutes, simulating the ageing process and analysing degradation kinetics. Variations in Ψ and Δ spectra were observed across the entire 0.7-5.9 eV spectral range, with five distinct anomalies, particularly in the UV region. An anomaly at approximately 66°C is attributed to the glass transition temperature Tg of BPhen, while another two at around 82°C and at around 112°C correspond to the first-order phase transition of TAPC, and Tg of CBP, respectively. The origins of the remaining anomalies at 91°C and 112°C are explored in this study, with a focus on interphase layer formation and morphological changes that emerges during heating. These findings provide insights into the stability of OLEDs under thermal stress.