Search Results (131)

This study addresses a major challenge in hyperthermia therapy: achieving fast and efficient heat generation in target tissues. A novel magneto-plasmonic nanostructure is developed by combining gold nanorods (GNRs) and iron oxide nanoparticles (IONPs), each synthesized independently to compare their individual and combined heating performance. A key innovation was the use of (3-mercaptopropyl)trimethoxysilane (MPTMS) as a covalent linker, enabling the stable integration of both components into a single hybrid system. Under simultaneous near-infrared (NIR) laser and alternating magnetic field exposure, the hybrid nanostructure exhibited a rapid and intense temperature rise, surpassing the effects of either material alone. A control sample consisting of a physical mixture of the two components (GNR + IONP) reached SAR values comparable to those of the covalently linked hybrid (GNR + MPTMS + IONP) under simultaneous excitation, the two being equal within experimental error. Although the chemical linkage modifies the optical absorbance of the GNRs and may partially restrict the Brownian relaxation of the magnetic nanoparticles, these effects do not translate into a measurable loss of heating efficiency under combined activation. Importantly, the covalent linkage yields a robust, structurally stable assembly whose components move together—an essential requirement for functionalities such as magnetic guidance and targeted delivery of the whole nanostructure, which a simple physical mixture cannot provide. As a physicochemical proof of concept, these results establish the dual-mode heating performance of the hybrid nanostructure in aqueous suspension and motivate the biological evaluation required for any future therapeutic use. Full article

Among the various types of magnetic field sensors, only a few can detect magnetic fields non-intrusively, and even fewer offer ultra-wideband capability with an extreme dynamic range. In this report, we present a magneto-optic B-field probe that can detect a magnetic field with negligible perturbation to the field it detects. The probe is compact and has a frequency bandwidth of DC to 2 GHz. Furthermore, this technique achieves a dynamic range that significantly exceeds 100 dB by utilizing different magneto-optic materials. The device is an intrinsic vector-field sensor that can measure the direction, amplitude, and phase of a time-varying magnetic field. It offers several advantages, including a compact size, high sensitivity, room-temperature operation, a wide dynamic range, and vector-sensing capabilities across a broad frequency range. These features make it suitable for a variety of applications, such as RF and microwave testing, extreme low-frequency applications, and biomedical uses. Full article

This paper presents a two-dimensional magneto-photo-thermoelastic model for a fiber-reinforced anisotropic semiconductor half-space subjected to optical excitation and a variable gravity field. The formulation is developed within the framework of generalized photo-thermoelasticity by considering the coupled interactions among thermal, elastic, carrier-density, electromagnetic, and gravity-induced effects. The constitutive equations of a fiber-reinforced anisotropic medium are employed, while the influences of the magnetic field and gravity are incorporated into the governing equations. A suitable nondimensionalization procedure is introduced, and the resulting coupled system is solved analytically using the normal mode technique and eigenvalue approach. Numerical results are obtained for the temperature, carrier density, displacement components, and stress distributions. The influence of the gravity parameter on the physical fields is investigated in detail. The results indicate that gravity significantly affects the mechanical and stress responses, whereas its effect on the thermal and carrier-density fields is comparatively less pronounced. A comparative study between silicon and germanium semiconductors is also carried out, revealing noticeable differences in the amplitudes and attenuation behavior of the coupled fields due to variations in material properties. The present study provides useful insights into coupled multiphysical interactions in semiconductor structures and may be relevant to applications in optoelectronic devices, photonic systems, smart composite materials, and aerospace technologies. Full article

Rapid room-temperature identification of gases and volatile organic compounds remains challenging for compact sensing platforms, particularly when chemically related analytes must be discriminated using accessible sensing materials. In this work, we evaluate whether magneto-optical surface plasmon resonance (MOSPR), combined with multi-spot sensing and conventional SPR readout from the same chip, can provide complementary response features for improved gas/VOC discrimination. The sensing spots are made from accessible chemicals and nanoparticles with plasmonic and magnetic properties. The sensor chip consists of a multilayer structure of metallic materials with both plasmonic and magnetic properties featuring enhanced sensitivity and stability. Measurements are made using a custom-built MOSPR instrument at relevant analyte concentrations. Analyte-specific sensor channels were selected for concentration-dependent calibration while the complete multivariate data were first explored using principal component analysis for supervised analyte classification. The combined 16-feature MOSPR/SPR model achieved an overall accuracy of 88.3% and a balanced accuracy of 87.6% under leave-one-concentration-block-out cross-validation compared with 66.2% and 65.7%, respectively, for the SPR measurement alone. These results show that MOSPR provides response information that encompasses and extends that obtained from conventional SPR measurements, thereby improving analyte discrimination. The proposed approach may provide a basis for future environmental monitoring and industrial process control, including real-time monitoring of harmful gaseous emissions pending further validation under application-specific conditions. Full article

Two-dimensional (2D) group-IV materials are promising for spintronics due to their silicon compatibility and tunable properties. In this work, we investigate the structural, electronic, magnetic, and optical properties of semi-hydrogenated 2D SiGe random alloys—where hydrogen atoms saturate only one side of the atomic plane—using density functional theory and many-body perturbation theory ($G{W}_0$). Substitutional disorder is modeled via representative high-symmetry configurations introduced by Baldereschi and co-workers to enable quasiparticle and optical simulations in large supercells. We demonstrate that these semi-hydrogenated alloys possess an intrinsic magnetic semiconducting ground state, arising from the electronic structure of the system, with an integer magnetic moment of $1{\mathsf{\mu }}_{\mathrm{B}}$ per primitive cell. The spin-resolved electronic structure features nearly flat frontier bands and a finite energy gap, which is significantly renormalized by quasiparticle corrections while maintaining robust spin polarization. These properties remain remarkably stable across different realizations of chemical disorder and over a wide range of alloy compositions considered in this work. Optical spectra calculated within the random phase approximation reveal a composition-dependent red-shift of the low-energy onset in the imaginary part of the dielectric function, consistent with the evolution of the quasiparticle electronic structure and the persistence of flat spin-polarized frontier bands. Our findings establish semi-hydrogenated 2D SiGe random alloys as a resilient model platform to explore interaction-driven magnetism in disordered two-dimensional systems, while simultaneously offering realistic prospects for spintronic and magneto-optoelectronic applications in the presence of chemical disorder. Full article

Ultrastrong magnetic fields, ranging from 100 T to 1000 T, are generated exclusively by destructive pulsed magnets. While various generation methods exist, this review focuses on the Single-Turn Coil (STC) and Electromagnetic Flux Compression (EMFC) techniques, which provide optimal environments for high-precision measurements in materials science. First, we present recent technological breakthroughs in the EMFC method that have successfully achieved fields exceeding 1000 T. We then describe specialized measurement infrastructures for magneto-optics, magnetization, and magneto-transport, highlighting the development of miniaturized all-plastic cryostats and custom sample holders designed for the dual extremes of cryogenic temperatures and megagauss fields. Representative physical phenomena revealed through these techniques are discussed, including quantum phase transitions in frustrated magnets, Aharonov–Bohm effects in carbon nanotubes, and semiconductor-to-metal transitions in strongly correlated systems. Furthermore, we address emerging measurement platforms such as magnetostriction, specific heat, and ultrasound velocity. Throughout this review, we emphasize the instrumentation and experimental refinements that ensure reliable data acquisition in the ultrastrong pulsed field regime. Full article

Organic–inorganic hybrid perovskites (OIHPs) have been widely used in fields such as solar cells, photodetectors, and light-emitting diodes due to their simple preparation by solution methods and excellent optoelectronic properties. In recent years, numerous scholars have delved deeply into the magneto-optical properties of perovskites and explored their potential applications in the magneto-optical field. Herein, we present the Faraday rotation characteristics of formamidinium lead bromide (Fabri₃) single crystals within the visible spectrum range. Firstly, FAPbBr₃ single crystals with high transparency and a size of 5.5 × 5.6 × 2 mm³ were prepared using the modified inverse temperature crystallization (MITC) method. The experimental results showed that the Verdet constant of FAPbBr₃ single crystal at 565 nm was up to 531.6 rad/(T·m). Furthermore, the FAPbBr₃ single crystal showed similar or an even higher Verdet constant when compared with the mature magneto-optical material TGG single crystal commonly used in the industry. The thermal simulation results of the FAPbBr₃ single crystal show low temperature dependence which achieves about 90% isolation transparency with a magnetic field of 0.35 T for 625 nm. This study demonstrates the outstanding Faraday rotation properties of FAPbBr₃ single crystals, thereby offering promising prospects for the development of perovskite materials in non-reciprocal devices such as optical isolators and optical circulators. Full article

Surface Acoustic Wave (SAW) technology, long central to analog signal processing and RF filtering, is undergoing a major renewal. Driven by advances that decouple SAWs from traditional piezoelectric materials and fixed-function devices, the field is gaining unprecedented control over acoustic, optical, and electronic interactions at the micro and nanoscale. This review synthesizes these developments across four fronts: new physical mechanisms for SAW manipulation, emerging material platforms, ranging from thin films to 2D systems, along with reconfigurable device architectures and circuits, and the expanding landscape of applications they enable. Optical methods are reshaping how SAWs are generated and controlled, bypassing the limits of conventional electromechanical coupling. Coherent optical excitation of high-Q SAW cavities via Brillouin-like optomechanical interactions now grants access to modes in non-piezoelectric substrates such as diamond and silicon, while on-chip SAW excitation in photonic waveguides through backward stimulated Brillouin scattering opens new integrated sensing routes. In parallel, magneto-acoustic experiments have revealed nonreciprocal SAW diffraction from resonant scattering in magnetoelastic gratings. On the device side, ZnO thin-film transistors integrated on LiNbO₃ exploit acoustoelectric coupling to realize voltage-tunable phase shifters; UHF Z-shaped delay lines achieve high sensitivity in a compact footprint; and parametric synthesis of wideband, multi-stage lattice filters targets 5G-class performance. Atomistic simulations show that SAW propagation in 2D MXene films can be engineered via surface terminations, while aerosol jet printing and SAW-assisted particle patterning provide agile, cleanroom-light fabrication of microfluidic and magnetic components. These advances enable applications ranging from hybrid quantum systems and quantum links to lab-on-a-chip particle control, SBS-based and UHF sensing, reconfigurable RF front-ends, and soft robotic actuators based on patterned magnetic composites. At the same time, optical techniques offer non-contact probes of dissipation, and MXenes and other emerging materials open new regimes of acoustic control. Conclusively, they are transforming SAW technology into a versatile, programmable platform for mediating complex interactions in next-generation electronic, photonic, and quantum systems. Full article

Transparent ceramics offer a uniquely accessible platform for examining Kerr-type optical phenomena through the lens of molecular structure and local electronic interactions. This review highlights both the magneto-optical (MOKE) and electro-optic (EOKE) forms of the Kerr effect and relates them to the accompanying Faraday and Cotton–Mouton responses. We briefly outline material classes exhibiting Kerr activity—from classic spinels and garnets to perovskites and modern composite ceramics. Particular attention is given to the molecular and atomic mechanisms underlying Kerr behavior—crystal symmetry, site-specific ionic coordination, covalency, electronic-level splitting, carrier localization, vacancy chemistry, and the influence of dopants on polarizability and nonlinear susceptibility. We also summarize advances in experimental setups that have improved measurement precision and spectral range. Selected examples demonstrate how molecular-scale control over electronic structure enables diverse and tunable Kerr responses in different ceramics. We conclude by identifying key remaining challenges in materials design and measurement techniques, and by pointing to future directions driven by improved synthesis and molecular-level engineering. Full article

Magnetooptics (MO) explores light—matter interactions in magnetized media and has advanced rapidly with progress in materials science, spectroscopy, and integrated photonics. This review highlights recent developments in fundamental principles, experimental techniques, and emerging applications. We revisit the canonical MO effects: Faraday, MO Kerr effect (MOKE), Voigt, Cotton—Mouton, Zeeman, and Magnetic Circular Dichroism (MCD), which underpin technologies ranging from optical isolators and high-resolution sensors to advanced spectroscopic and imaging systems. Ultrafast spectroscopy, particularly time-resolved MOKE, enables femtosecond-scale studies of spin dynamics and nonequilibrium processes. Hybrid magnetoplasmonic platforms that couple plasmonic resonances with MO activity offer enhanced sensitivity for environmental and biomedical sensing, while all-dielectric magnetooptical metasurfaces provide low-loss, high-efficiency alternatives. Maxwell-based modeling with permittivity tensor ($\epsilon$) and machine-learning approaches are accelerating materials discovery, inverse design, and performance optimization. Benchmark sensitivities and detection limits for surface plasmon resonance, SPR and MOSPR systems are summarized to provide quantitative context. Finally, we address key challenges in material quality, thermal stability, modeling, and fabrication. Overall, magnetooptics is evolving from fundamental science into diverse and expanding technologies with applications that extend far beyond current domains. Full article

This study investigates the dynamic magneto-optical properties of ferrofluid thin films, focusing on how magnetic fields induce light–matter interactions using a device known as Ferrocell. Our findings reveal that incident light interacts with self-assembled, anisotropic nanoparticle structures, transforming the ferrofluid into a highly responsive optical medium. Monochromatic laser experiments confirmed the direct correlation between laser color and diffracted light color offering direct insights into particle orientation and aggregate morphology. We observed significant chromatic shifts, especially in regions under strong perpendicular magnetic fields, which provide compelling evidence of structural colors. This phenomenon stems from wavelength-selective interference and diffraction, reminiscent of photonic crystal behavior, yet characterized by short-range order, classifying the material as a photonic glass. Full article

A multimode magneto-optical fiber based on Tb³⁺-containing borogermanate glass was designed, fabricated, and characterized, aiming at potential sensing applications. There are continuing challenges in the development of single-mode (SMF) or multimode (MMF) optical fibers doped with rare-earth (RE) ions and exhibiting high Verdet constants, related to devitrification of the precursor glass. Most RE-doped glass compositions are not suitable as precursors for core-cladding fiber production due to devitrification processes and consequent poor optical quality. Application as Faraday rotators is limited by the intrinsically low Verdet constant of silica (~0.589 rad T⁻¹ m⁻¹ at 1550 nm and 0.876 rad T⁻¹ m⁻¹ at 1310 nm). Borogermanate glasses are good candidates for manufacturing optical fibers due to their excellent potential to solubilize high concentrations of Tb³⁺ ions as well as satisfactory thermal stability. In this work, a magneto-optical core-cladding borogermanate fiber with a 227 μm diameter was fabricated, with characterization using differential scanning calorimetry (DSC), thermomechanical analysis (TMA), viscosity measurements, M-lines spectroscopy, UV-Vis-NIR absorption spectroscopy, the cut-back technique, and magneto-optical measurements. The measured numerical aperture (NA) was 0.183, with minimum attenuation of 13 dB m⁻¹ at 1270 nm. The Verdet constant (V_B) reached −6.74 rad T⁻¹ m⁻¹ at 1330 nm. Full article

The use of magnetic materials, such as ferrofluids, is of great importance in biomedical applications, and as a result, interest in studying their magneto-optical properties has grown significantly in recent years. Therefore, in this work, magnetic nanoparticles were synthesized with chitosan coating, leaving the product as a ferrofluid in aqueous solution. Structural, morphological, magnetic, and optical characterization was carried out obtaining a cubic structure centered on the faces, a spherical morphology with a size distribution of 10–14 nm according to TEM images and a magnetic saturation of 53 emu/g. In the optical properties, the effect of chitosan shell on the forbidden band was studied, showing a blue-shifting effect, due to reduction on the inner magnetic nanoparticles size. Full article

Recent achievements in ultrafast spin physics have enabled the use of heterostructures composed of ferromagnetic (FM)/non-magnetic (NM) thin layers for terahertz (THz) generation. The mechanism of THz emission from FM/NM multilayers has been typically ascribed to the inverse spin Hall effect (ISHE). In this work, we probe the mechanism of the ISHE by inserting a second ferromagnetic layer in the form of an alloy between the FM/NM system. In particular, by utilizing the co-sputtering technique, we fabricate Fe/L1₀-FePt/Pt ultra-thin heterostructures. We successfully grow the tetragonal phase of FePt (L1₀-phase) as revealed by X-ray diffraction and reflection techniques. We show the strong magnetic coupling between Fe and L1₀-FePt using magneto-optical and Superconducting Quantum Interference Device (SQUID) magnetometry. Subsequently, by utilizing THz time domain spectroscopy technique, we record the THz emission and thus we the reveal the efficiency of spin-to-charge conversion in Fe/L1₀-FePt/Pt. We establish that Fe/L1₀-FePt/Pt configuration is significantly superior to the Fe/Pt bilayer structure, regarding THz emission amplitude. The unique trilayer structure opens new perspectives in terms of material choices for the future spintronic THz sources. Full article

The poor magnetic and magneto-optical properties of BiFeO₃, along with its significant lattice mismatch with silicon, have limited its application in silicon-based integrated magneto-optical devices. In this study, co-doping with Sr²⁺ and Ti⁴⁺ ions effectively transformed the trigonal structure of BiFeO₃ into a cubic phase, thereby reducing the lattice mismatch with silicon to 2.8%. High-quality, highly oriented, silicon-based cubic Sr,Ti:BiFeO₃ thin films were successfully fabricated using radio frequency magnetron sputtering. Due to the induced lattice distortion, the characteristic periodic spiral spin antiferromagnetic structure of BiFeO₃ was suppressed, resulting in a significant enhancement of the saturation magnetization of cubic Bi_0.5Sr_0.5Fe_0.5Ti_0.5O₃ (48.0 emu/cm³), compared to that of pristine BiFeO₃ (5.0 emu/cm³). Furthermore, the incorporation of Sr²⁺ and Ti⁴⁺ ions eliminated the birefringence effect inherent in trigonal BiFeO₃, thereby inducing a pronounced magneto-optical effect in the cubic Sr,Ti:BiFeO₃ thin film. The magnetic circular dichroic ellipticity (ψ_F) of Bi_0.5Sr_0.5Fe_0.5Ti_0.5O₃ reached an impressive 2300 degrees/cm. Full article