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We have reported a systematic investigation on structural, magnetic, magnetodielectric and magnetoimpedance characteristics of Y-type Ba 2 Mg 2 (Fe 1−x Mn x ) 12 O 22 (0 ⩽ x ⩽ 0.12) hexaferrite synthesized by solid-state reaction route. Rietveld refinement of x-ray diffraction pattern confirms the phase purity of all the samples with rhombohedral crystal structure. The Mn dopant modulates not only superexchange angle near to the boundary of magnetic blocks but also magnetic transition temperature. Temperature-dependent magnetization data suggests that due to Mn doping at Fe sites, ferrimagnetic to proper screw transition temperature (T II ) increases from 190 K to 208 K, while there is a decrease in proper screw to longitudinal conical spin transition temperature (T I ) from 35 K to 25 K. We observe remarkable decrease in the magnetic field from 20 kOe to 12 kOe to produce intermediate spin ordering from ferrimagnetic ordering which can be understood because of modification of superexchange angle due to Mn doping. The value of loss tangent decreases with increasing doping concentration at 300K, i.e. ~60% and 180% in BMFM4 (x = 0.04) and BMFM8 (x = 0.08) respectively as compared to BMF, suggesting the evolution of intrinsic feature in the doped samples. Magnetodielectric (MD) effect shows that in the low-frequency regime, the robust MD effect is because of Maxwell-Wagner interfacial polarization, whereas in the high-frequency regime intrinsic effect dominates. Further, magnetoimpedance measurement confirms the presence of substantial intrinsic MD% (~6%) at 1.3 T applied field at 300 K for 4% Mn-doped sample. Finally, the nature and strength of magnetoelectric coupling in BMFM4 and BMFM8 samples at 300 K is found to be biquadratic (P 2 M 2 ) and maximum strength of coupling is 3.09 × 10 −4 emu 2 g −2 and 2.34 × 10 −4 emu 2 g −2 , respectively.

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We have investigated the structural, magnetic, magnetodielectric, and magnetoimpedance characteristics of Aurivillius-structured Bi 5 Ti 3 FeO 15 (BTFO) synthesized by a generic solid-state reaction route. Rietveld refinement of X-ray diffraction pattern at room temperature (RT) confirms orthorhombic crystal structure (space group A2 1 am). In BTFO, octahedral distortion of the perovskite unit occurs due to antisite defects Fe/Ti in the BO 6 site, which results in the formation of Fe-O clusters. Raman spectra also reveal Ti/FeO6 octahedral distortion due to the vibration of Bi ions in the perovskite layer. Magnetic fielddependent magnetization (M-H) and electric field-dependent polarization (P-E) measurement at RT indicate the existence of multiferroic behavior in BTFO. The M-H hysteresis at 5 K suggests that the non-interacting superparamagnetic state is dominant over the local short-range antiferromagnetic (AFM) ordering. The AFM interaction arises due to the random distribution of antisite defects Fe/Ti causing the distorted Fe-O octahedral unit. These canted spin interact via the Dzyaloshinskii-Moriya (DM) interaction. The superexchange interaction between the Fe-O-Fe ions is stronger than the next-nearest-neighboring Fe-O-O-O-Fe interaction. This happens due to the intermediate fluorite-like layer (Bi 2 O 2 ) 2? , which opposes the long-range exchange interaction. The negative magnetodielectric (MD) effect is more prominent at low frequency (* 100 Hz) due to the extrinsic contribution. In contrast, in the high-frequency region ([ 50 kHz), the intrinsic contribution dominates, which is further ascertained by magnetoimpedance (MI) measurement. The maximum magnitude of the MD effect is found to be * 0.32% at a magnetic field of 13 kOe at 150 K. Lastly, the ferroelectric characteristic of the sample is obtained from the P-E measurement with a polarization value of 4.35 lC/cm 2 with an applied electric field of 70 kV/ cm.

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Among the living organisms, the most important metabolic process is health, or what we can say as the power of living and the basic right to get quality healthcare. In the coming era, the internet will play an important role in monitoring and executing the issues related to the health system of humans through automated sensor response using IoT. IoT connects device to device, things to things, as well as the human body to the network system through the sensors. It can be used to monitor human health-related issues like sugar level, blood pressure level, fever and keep track of a patient's pulse rate and any disease that may be harmful to human life. Today, due to a lack of resources in the world, people are facing many problems related to health.