The objective of mechanical stress sensor is to measure the applied pressure or provide control standard to the process. In order to accomplish this, most of the stress sensors convert mechanical stress into electronic signal. Ferrites are the best known magnetic semiconductors. This paper brings out the variation in inductance of the micro-inductor made from [Formula: see text] on application of mechanical stress. [Formula: see text] ferrite nanoparticles are synthesized by sol–gel autocombustion technique. The ferrite powder thus obtained is double sintered at 450[Formula: see text]C and 870[Formula: see text]C in a microwave furnace. The X-ray diffraction pattern of the ferrite confirms spinal structure. The frequency spectrum of dielectric constant is done in the range of 100 to 5 MHz frequency. The variation of inductance [Formula: see text]% with applied compressive stress on the micro-inductor made from the ferrite is measured in the range of 0–8 MPa.

Madhuri W

Department of Physics

School of Advanced Sciences

Vellore Campus

Kalainathan S

Kumar S

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Synthesis and characterization of microinductor made of NiCuZn nanoferrite

Modern Physics Letters B

NiCuZn ferrite with composition of (NCu0.10Zn0.60F) (where , 0.02, 0.04, 0.06, 0.08, and 0.10) was prepared by the conventional ceramic double sintering technique. The formation of single phase was confirmed by X-ray diffraction. The microstructural features were also studied by electronic microscopy and are reported. Initial permeability measurements on these samples were carried out in the temperature range of 30 to 300°C. The effect of external applied stress on the open magnetic circuit type coil with these ferrite cores was studied by applying uniaxial compressive stress parallel to the magnetizing direction and the change in the inductance was measured. The variation of inductance (ΔL/L)% increases up to certain applied compressive stress and there after it decreases, showing different stress sensitivities for different compositions of ferrites studied in the present work. The variation of ratio of inductance (ΔL/L)% with external applied compressive stress was examined. These results show that the Ni0.42 Cu0.10Zn0.60Fe1.76O3.76 and Ni0.44Cu0.10Zn0.60Fe1.72O3.72 samples are found to be suitable for inductive stress sensor applications.

Fulltext

Journal of Ceramics

Possibility of NiCuZn Ferrites Composition for Stress Sensor Applications

Polycrystalline MgCuZn ferrites with chemical formula Mg 0.50-xCuxZn0.50Fe2O4 (x = 0.00, 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) were prepared by microwave sintering method. These powders were calcined, compacted and sintered at 950 °C for 30 min. Structural, microstructural and elemental analyses were carried out using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectrometry (EDS), respectively. The lattice parameter is found to increase with increasing copper content. A remarkable densification is observed with the addition of Cu ions in the ferrites. The sintered ferrite was characterized for initial permeability, dielectric constant and dielectric loss tangent and ac conductivity measurements. The temperature variation of the initial permeability of these samples was carried out from 30 °C to 200 °C. The dielectric constant, dielectric loss tangent and ac conductivity have been measured in the frequency range of 100 Hz to 1 MHz. Initial permeability and dielectric constant were found to increase and dielectric loss decreased with Cu substitution for Mg, up to x = 0.20. The ferrite powder prepared is suitable for the application in multilayer chip inductor due to its low-temperature sinterability, good magnetic properties and low loss at high frequency. © 2010 Elsevier B.V.

Materials Science and Engineering C

Influence of copper substitution on magnetic and electrical properties of MgCuZn ferrite prepared by microwave sintering method

San Francisco Estuary and Watershed Science

Climate and Land-Use Controls on Surface Water Diversions in the Central Valley, California

NiCuZn ferrites are widely employed for many electronic applications, but can be replaced by MgCuZn ferrites owing to their superior properties like low magnetostriction, environmental stability, low stress sensitivity and low cost. In view of this, a series of non-stoichiometric MgCuZn ferrites (Mg 0.5-xCuxZn0.5Fe1.9O 4-δ with x = 0.0, 0.05, 0.10, 0.15, 0.20, 0.25) have been successfully synthesized by both conventional and microwave sintering techniques. The non-stoichiometry was intentionally introduced into the ferrites to ensure high resistivity of the samples. X-ray diffraction patterns confirm the single phase spinel structure in both cases. The elemental composition of these ferrites was analysed by energy-dispersive x-ray spectrometry. The samples sintered by the microwave technique were found to be denser than the conventionally sintered samples. The initial permeability of MgCuZn ferrites was studied with an increase in copper concentration from x = 0.0 to 0.25. The temperature variation of the initial permeability of these samples was carried out from 30 °C to 150 °C. The results are discussed in the light of microstructure variations of the conventionally and microwave sintered samples. The phenomena involved in microwave sintering are also discussed. © 2009 IOP Publishing Ltd.

Journal of Physics D: Applied Physics

Comparison of initial permeability of MgCuZn ferrites sintered by both conventional and microwave methods

Journal of Magnetism and Magnetic Materials

High-performance zig-zag and meander inductors embedded in ferrite material

Journal	Modern Physics Letters B
Publisher	World Scientific Pub Co Pte Lt
ISSN	0217-9849
Open Access	0