Boosting the Tunable Microwave Scattering Signature of Sensing Array Platforms Consisting of Amorphous Ferromagnetic Fe2.25Co72.75Si10B15 Microwires and Its Amplification by Intercalating Cu Microwires

Abstract

The following work addresses new configurations of sensing array platforms that are composed of Co-based amorphous ferromagnetic microwires (MWs) to obtain an enhanced modulation of the microwave scattering effects through the application of low strength DC or AC magnetic fields. An amorphous MW is an ultrasoft ferromagnetic material (coercivity ~0.2 Oe) with a circumferential magnetic anisotropy that provides a high surface sensitivity when it is subjected to an external magnetic field. Firstly, microwave scattering experiments are performed as a function of the length and number of MWs placed parallel to each other forming an array. Subsequently, three array configurations are designed, achieving high S21 scattering coefficients up to about −50 dB. The influence of DC and AC magnetic fields on S21 has been analyzed in frequency and time domains representation, respectively. In addition, the MWs sensing array has been overlapped by polymeric surfaces and the variations of their micrometric thicknesses also cause strong changes in the S21 amplitude with displacements in the frequency that are associated to the maximum scattering behavior. Finally, a new concept for amplifying microwave scattering is provided by intercalating Cu MWs into the linear Co-based arrays. The designed mixed system that is composed by Co-based and Cu MWs exhibits a higher S21 coefficient when compared to a single Co-based MW system because of higher electrical conductivity of Cu. However, the ability to modulate the resulting electromagnetic scattering is conferred by the giant magneto-impedance (GMI) effects coming from properties of the ultrasoft amorphous MWs. The mixed array platform covers a wide range of sensor applications, demonstrating the feasibility of tuning the S21 amplitude over a wide scattering range by applying AC or DC magnetic fields and tuning the resonant frequency position according to the polymeric slab thickness.

Generation of Defective Few-Layered Graphene Mesostructures by High-Energy Ball Milling and Their Combination with FeSiCuNbB Microwires for Reinforcing Microwave Absorbing Properties

“…The MWs are obtained by the rapid quenching Taylor-Ulitosky technique, and they are covered by Pyrex (borosilicate glass) to ensure their shape anisotropy and environmental stability. − The metal core has a diameter of 4.7 μm and a total diameter of 15.8 μm with the Pyrex. The MWs are subsequently cut to a length of 2 mm, and these dimensions provide absorptions in the microwave electromagnetic range. , …”

“…The MWs are subsequently cut to a length of 2 mm, and these dimensions provide absorptions in the microwave electromagnetic range. 26,33 Microwave absorbing paints are prepared with a V f between 0.19 and 0.55% for MWs and between 0.65 and 2.60% for DFLGM milled powders for 240 min. The above mixtures are added to 50 g of commercial paint, and the resulting product is homogeneously stirred.…”

Application of Ferromagnetic Microwires as Temperature Sensors in Measurements of Thermal Conductivity

“…It was demonstrated that Co-rich amorphous microwires can be used to create a number of miniature sensors for measuring mechanical stresses, magnetic fields, temperature, etc. [12][13][14][15] Currently, ferromagnetic microwires are also used as fillers in multifunctional composite materials with electromagnetic functions [16][17][18][19].…”

Numerical Investigation of Ferrofluid Preparation during In-Vitro Culture of Cancer Therapy for Magnetic Nanoparticle Hyperthermia

“…Hence, in-silico studies based on various numerical methods are employed to explore the parameters that optimize the hyperthermia process to evaluate the temperature [ 7 , 11 , 12 , 13 , 14 ] and thermal damage of the tumor containing nanoparticles [ 15 , 16 ]. Many research efforts are currently unde way to synthesize specialized MNPs with various chemical structures and shapes [ 17 , 18 , 19 , 20 ] that are suitable for targeted drug delivery [ 21 , 22 , 23 ], hyperthermia [ 24 , 25 , 26 ], and photo-thermal procedures [ 27 , 28 , 29 ]. Magnetic fluids are also being successfully used in some critical industrial applications [ 30 ].…”