Passive, Highly-Sensitive, Room-Temperature Magnetic Field Sensors and Arrays for Detection and Imaging of Hidden Threats in Urban Environments

AbstractWe describe magnetic field sensors based on a recently discovered magnetoresistance (MR) effect in nonmagnetic organic semiconductor sandwich devices. The MR effect reaches up to 10% in a magnetic field of 10 mT at room temperature. We perform an extensive experimental characterization of this effect. We found that the MR effect is only weakly temperature dependent and does not depend on sign and direction of the applied magnetic field. We also measured the device response to alternating magnetic fields up to 100 kHz. To the best of our knowledge, the discovered MR effect is not adequately described by any of the MR mechanisms known to date.

Download Full-text

Application of magnetoelectric sensors in biomedicine

Journal of Physics Conference Series ◽

10.1088/1742-6596/2052/1/012022 ◽

2021 ◽

Vol 2052 (1) ◽

pp. 012022

Author(s):

V S Leontiev ◽

V N Lobekin ◽

A F Saplev ◽

E A Zueva ◽

E E Ivasheva ◽

...

Keyword(s):

Magnetic Field ◽

Human Body ◽

Magnetoelectric Effect ◽

High Sensitivity ◽

Ease Of Use ◽

Magnetic Noise ◽

Magnetic Field Sensors ◽

Non Invasive ◽

Highly Sensitive ◽

Magnetoelectric Sensors

Abstract The prospects of applying highly sensitive magnetic field sensors based on the magnetoelectric effect in biomedicine are discussed in this paper. When developing highly sensitive magnetic field sensors, it is necessary to take into account the magnitude of the equivalent magnetic noise, as well as the mass and size dimensions and ease of use of the system that the sensor is included in. One of the most relevant areas discussed in the article is the application of magnetoelectric magnetic field sensors for magnetocardiography, magnetoencephalography, etc. These methods are non-invasive, have high sensitivity and are easy to use. They also have wide opportunities in detecting weak biomagnetic signals when examining the state of the human body and providing the necessary assistance.

Download Full-text

Unravelling the nature of magneto-electric coupling in room temperature multiferroic particulate (PbFe0.5Nb0.5O3)–(Co0.6Zn0.4Fe1.7Mn0.3O4) composites

Scientific Reports ◽

10.1038/s41598-021-82399-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Krishnamayee Bhoi ◽

H. S. Mohanty ◽

Ravikant ◽

Md. F. Abdullah ◽

Dhiren K. Pradhan ◽

...

Keyword(s):

Magnetic Field ◽

Room Temperature ◽

Single Phase ◽

Microstructural Analysis ◽

Magnetic Ordering ◽

Particulate Composite ◽

Capacitance Measurement ◽

Magnetic Field Sensors ◽

Spintronic Devices ◽

Electric Coupling

AbstractMultiferroic composites are promising candidates for magnetic field sensors, next-generation low power memory and spintronic devices, as they exhibit much higher magnetoelectric (ME) coupling and coupled ordering parameters compared to the single-phase multiferroics. Hence, the 3-0 type particulate multiferroic composites having general formula (1 − Φ)[PbFe0.5Nb0.5O3]-Φ[Co0.6Zn0.4Fe1.7Mn0.3O4] (Φ = 0.0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, (1 − Φ) PFN-ΦCZFMO) were prepared using a hybrid synthesis technique. Preliminary structural and microstructural analysis were carried out using XRD and FESEM techniques, which suggest the formation of 3-0 type particulate composite without the presence of any impurity phases. The multiferroic behaviour of the composites is studied with polarization versus electric field (P-E) and magnetization versus magnetic field (M-H) characteristics at room temperature. The nature of ME coupling was investigated elaborately by employing the Landau free energy equation along with the magneto-capacitance measurement. This investigation suggests the existence of biquadratic nature of ME coupling (P2M2). The magneto-electric coupling measurement also suggests that strain mediated domain coupling between the ferroelectric and magnetic ordering is responsible for the magneto-electric behaviour. The obtained value of direct ME coefficient 26.78 mV/cm-Oe for Φ = 0.3, found to be higher than the well-known single-phase materials and polycrystalline composites.

Download Full-text

Höchstempfindliche Magnetfeldsensoren für den Niederfrequenzbereich (Highly Sensitive Magnetic Field Sensors for the Low Frequency Regime)

tm - Technisches Messen ◽

10.1524/teme.2001.68.6.261 ◽

2001 ◽

Vol 68 (6/2001) ◽

Author(s):

M. Schilling

Keyword(s):

Magnetic Field ◽

Low Frequency ◽

Magnetic Field Sensors ◽

Highly Sensitive ◽

Frequency Regime

Download Full-text

Electrical Transport Properties of Rare Earth Doped Pentatellurides

MRS Proceedings ◽

10.1557/proc-691-g5.2 ◽

2001 ◽

Vol 691 ◽

Author(s):

Nathan D. Lowhorn ◽

Terry M. Tritt ◽

R. T. Littleton ◽

Edward E. Abbott ◽

J. W. Kolis

Keyword(s):

Magnetic Field ◽

Rare Earth ◽

Electrical Transport ◽

Low Temperatures ◽

Room Temperature ◽

Peak Temperature ◽

Electrical Transport Properties ◽

Zero Crossing ◽

Highly Sensitive ◽

Rare Earth Doped

ABSTRACTThe transition metal pentatellurides HfTe5 and ZrTe5 exhibit a broad resistive anomaly as a function of temperature. This behavior is also reflected in the thermopower as it changes from a large positive value below room temperature to a large negative value at lower temperatures with the zero crossing corresponding well with the peak temperature of the resistive anomaly. The large values of the thermopower at low temperatures (T ≈ 150 K) have made these materials attractive for investigation for potential low temperature thermoelectric applications. The magnitude of the resistive peak and the peak temperature are highly sensitive to doping as well as external influences such as magnetic field and pressure. In this study we examine the effect of doping with various rare earth elements (RE = Ce, Sm and Dy) and the subsequent effects on the electrical resistivity and the thermopower. These results will be discussed in relation to the thermoelectric performance of these materials.

Download Full-text