The rapid expansion of the Internet of Things (IoT), wearable electronics, and smart surfaces has accelerated the development of transparent, flexible, and miniaturized electronic technologies [...]
This review analyzes recent advances in fluxgate magnetometers. It introduces an innovative concept of using magnetically ordered composite and crystalline structures made of ferrites or conducting ferromagnetic materials as fluxgate cores. These active physical media enable new multifactor excitation methods, qualitatively improving output parameters. Unlike conventional approaches restricted to magnetic permeability modulation, the authors theoretically justify processes based on the interplay of five physical factors: indirect exchange, magnetostriction, dynamic inhomogeneities, magnetoelectric interaction, and chirality. This paper systematizes original patented modulator designs. These include electrodynamic modulators implemented as compact resonant C antennas and devices utilizing the acoustic magnetoelastic effect, local magnetic inhomogeneities, or electromagnetic-acoustic excitation. Furthermore, the hardware implementation of a specialized two-component fluxgate magnetometer is considered. This device provides high-precision measurements of geomagnetic field parameters for shallow geophysical exploration and navigation systems. Experimental data confirm a significant increase in sensitivity, interference immunity, and transformation precision under extremely low power consumption. This review establishes a solid foundation for a promising applied direction at the intersection of metrology and spintronics.
For the first time, the hole mobility values for benzo[f]- and naphtho[1,2-f]-annelated [1,2,5]oxadiazolo[3,4-b]thieno[3,2-h]quinoxalines were determined experimentally by using the space-charge-limited current method. Analysis of the X-ray diffraction data for naphtho[1,2-f][1,2,5]oxadiazolo[3,4-b]thieno[3,2-h]quinoxaline revealed significant π–π stacking, which may be attributed to enhanced electron mobility. These findings are further supported by the observed low hole conductivity values, which reached 4.10 × 10−9 cm2·V−1·s−1. Therefore, polycyclic compounds based on the furazano[3,4-b]pyrazine core can be considered a convenient scaffold for developing both electron and hole transport materials in various organic photovoltaic devices.
This manuscript investigates a biosensor based on a gadolinium (Gd)-doped hafnium oxide (HfO2) ferroelectric–dielectric (FE-DE) heterostructure for high-sensitivity, low-power biomolecule detection. The sensing cavity consists of a dielectric layer and a biomolecule-filled region, where different filling conditions (0%, 50%, 75%, and 100%) emulate realistic sensing environments. The dielectric properties of the biomolecule changes, which results in changes of the dielectric capacitance, thus improving capacitance matching with the ferroelectric layer and stabilizing the negative-capacitance effect. This intrinsic voltage amplification enhances the electrical response of the biosensor. Electrical characteristics, including charge–voltage, energy–charge, capacitance–voltage, and voltage amplification, were analyzed for biomolecules with dielectric constants ranging from 1 to 12. Higher-dielectric-constant biomolecules exhibited superior sensing performance; for example, gelatin (K = 12) achieved the highest sensitivity of 1.9632 at 100% cavity filling, along with the maximum voltage amplification. To evaluate the impact of amplification, the amplified dielectric voltage was applied to the gate of a 50 nm NMOS transistor. The enhanced gate voltage improved the drain current and transconductance and enabled a subthreshold swing below the conventional thermal limit of 60 mV/dec. A feasible fabrication plan is demonstrated to show the possible realization of the sensor system. These outcomes indicate that the proposed Gd-doped HfO2-based FE-DE heterostructure is capable of efficiently magnifying the dielectric changes caused by biomolecules, thus offering an encouraging framework for future low-power and high-sensitivity biosensing applications.
Dissolved oxygen concentration is a key parameter determining the oxidation and corrosion behavior of structural materials in lead-based fast reactor coolants. Therefore, achieving high-precision in-situ oxygen measurement in LBE systems is a fundamental technical requirement for implementing oxygen-controlled corrosion protection. Currently, nuclear-grade Bi/Bi2O3 solid-state electrochemical oxygen sensors have a minimum effective operating temperature of 350 °C, which prevents them from meeting the real-time oxygen monitoring needs under low-temperature conditions. This temperature limitation has become a major bottleneck for the engineering application of oxygen control technology. To address these requirements and challenges, this study develops a novel electrochemical oxygen sensor based on an 8 mol% Y2O3-stabilized ZrO2 (8YSZ) solid electrolyte and La0.6Sr0.4Co0.2Fe0.8O3±δ (LSCF) electrode system. Comparative experiments with Bi/Bi2O3 sensors are conducted to quantitatively assess the advantages of the LSCF/Air sensor in low-temperature applications within 205~550 °C. Furthermore, considering the irradiation environment in nuclear reactors, oxygen ion irradiation was employed as an accelerated simulation method to preliminarily investigate the electrochemical transport properties of 8YSZ after irradiation. The effects of oxygen ion irradiation on the apparent impedance and apparent oxygen ion conductivity of 8YSZ were evaluated. The results show that the LSCF/Air oxygen sensor has the potential to extend the lower operating-temperature limit of 8YSZ-based oxygen sensors in static, oxygen-saturated LBE environments. Oxygen ion irradiation increased the apparent impedance and decreased the apparent ionic conductivity of the tested 8YSZ samples. These results provide preliminary experimental data for the development of oxygen sensors for oxygen monitoring and corrosion control in liquid-metal-cooled reactor systems over a wider temperature range.
