High-resolution magnetic sensors in ferrite/piezoelectric heterostructure with giant magnetodielectric effect at zero bias field

2021 ◽  
Vol 92 (4) ◽  
pp. 045006
Author(s):  
Jitao Zhang ◽  
Jiahui Liu ◽  
Qingfang Zhang ◽  
D. A. Filippov ◽  
Kang Li ◽  
...  
Keyword(s):  
High Resolution ◽  
Bias Field ◽  
Magnetic Sensors ◽  
Zero Bias ◽  
Magnetodielectric Effect

Studies of Electrical Polarization Fatigue in SrBi2Ta2O9 Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
K. M. Lee ◽  
D. Thomas ◽  
S. H. Kim ◽  
J. P. Maria ◽  
A. I. Kingon ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Oxygen Vacancies ◽  
Remanent Polarization ◽  
Energy Levels ◽  
Bias Field ◽  
Charge Carriers ◽  
Temperature Dependent ◽  
Zero Bias ◽  
Electrical Polarization

AbstractThe polarization suppression and electrical properties directly associated with the electrical polarization fatigue in SrBi2Ta2O9system were systematically investigated using Pt/SBT/Pt capacitors. Three general observations were made after 109 switching cycles: (i) ∼95% of the remanent polarization was conserved, (ii) both high and zero bias field capacitance decreased, and (iii) leakage current density increased from approximately 10−7 to 10−5 A/cm2at ∼30kV/cm2. In addition, the “knee” field, at which the leakage abruptly increases, assumed smaller values with cumulative switching cycles. Temperature dependent leakage data was collected for both as-deposited and field-cycled samples. Based on these results, we propose the possibilities of enhanced concentration of charge carriers or additional reductions in interfacial conduction barriers. Motion of oxygen vacancies to less-shallow energy levels near electrode/ferroelectric interface may allow this mechanism to occur.

Micromagnetic Modeling of Nanocontact Spin-Torque Oscillators With Perpendicular Anisotropy at Zero Bias Field

2008 ◽  
Vol 44 (11) ◽  
pp. 2512-2515 ◽  
Author(s):  
V. Puliafito ◽  
B. Azzerboni ◽  
G. Consolo ◽  
G. Finocchio ◽  
L. Torres ◽  
...  
Keyword(s):  
Bias Field ◽  
Spin Torque ◽  
Perpendicular Anisotropy ◽  
Zero Bias ◽  
Micromagnetic Modeling ◽  
Spin Torque Oscillators

On Compensating for Magnetometer Swing in UAV Magnetic Surveys

2020 ◽  
Author(s):  
Callum Walter ◽  
Alexander Braun ◽  
Georgia Fotopoulos
Keyword(s):  
High Resolution ◽  
Electromagnetic Interference ◽  
Degrees Of Freedom ◽  
Mineral Exploration ◽  
Magnetic Measurement ◽  
Magnetic Sensors ◽  
Measurement Unit ◽  
Horizontal Gradient ◽  
Optically Pumped ◽  
Aeromagnetic Survey

<p>Natural resource exploration has advanced in recent years through integrating unmanned aerial vehicles (UAVs) with high-resolution magnetometer payloads. One design consideration when integrating these systems for mineral exploration applications is ensuring that the magnetic measurement quality is comparable to the previously established methods of terrestrial magnetic and aeromagnetic surveying. High-resolution optically pumped magnetometers, employing a resolution of 0.1 - 0.01 nT, are the standard magnetic sensors used in both manned terrestrial magnetic and aeromagnetic surveys. Integrating a high-resolution optically pumped magnetometer in a multi-rotor UAV payload bay will compromise the integrity of the total magnetic intensity (TMI) measurements due to the electromagnetic interference generated by the brushless permanent magnet synchronous motors and other onboard electromagnetic components. One solution involves physically suspending the high-resolution magnetometer below the resolvability limit of the electromagnetic interference via a semi-rigid mount. However, the swinging motions of the high-resolution magnetometer through the geomagnetic field while in this configuration have the potential to introduce periodic variations in the collected TMI data, compromising quality. Within this study, a UAV-borne aeromagnetic survey was conducted over a mineral exploration target to assess the potential impact of magnetometer swing on collected UAV-borne TMI data. A DJI-S900 multi-rotor UAV and a GEM Systems Potassium Vapour Magnetometer (GSMP-35U) were used to fly a 500 m by 700 m grid, using a line spacing of 25 m and a flight elevation of 35 m above the ground.The optically pumped magnetometer was suspended outside the resolvability limit of the electromagnetic interference below the UAV via a semi-rigid mount. A nine degrees of freedom inertial measurement unit (IMU) was fixed to the semi-rigid mount and a Kalman filter was applied to post-process the measurements calculating the positional variations (pitch, yaw and roll) of the magnetometer. Spectral analysis was applied to the UAV-borne TMI measurements and the IMU positional data assessing contributions to the TMI signal from the swinging, semi-rigidly mounted magnetometer. Periodic signals were observed within the recorded TMI data directly relating to the swinging frequency of the magnetometer in pitch and roll throughout flight. The amplitude of the periodic TMI variations was variable (< 1 nT – 5 nT) throughout the survey and depended on the horizontal gradient of the ambient magnetic field and the arc length of the magnetometer swing. The magnetometer swinging frequency (~0.35 Hz) was determined to be primarily dependant on the magnetometer suspension length. Overall, the wavelength of the periodic TMI variations due to the swinging motions was characterized with the IMU measurements and determined to be spectrally unique from the longer wavelength geological signals targeted within the survey area. Due to the wavelengths of the targeted and untargeted signals not spectrally overlapping, the TMI variations related to magnetometer swing noise were filtered out. The design factors controlling the wavelengths of the targeted geologic signals (flight speed) and untargeted magnetometer swing noise (suspension length) must be considered when integrating high-resolution magnetometers on multi-rotor UAVs, such that the wavelengths do not spectrally overlap and phase-based compensation algorithms are not required.</p>

scholarly journals Image Fusion for High-Resolution Optical Satellites Based on Panchromatic Spectral Decomposition

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2619 ◽  
Author(s):  
Luxiao He ◽  
Mi Wang ◽  
Ying Zhu ◽  
Xueli Chang ◽  
Xiaoxiao Feng
Keyword(s):  
High Resolution ◽  
Image Fusion ◽  
Spectral Decomposition ◽  
Spectral Image ◽  
Zero Bias ◽  
Spectral Bands ◽  
Fused Image ◽  
Transformation Methods ◽  
Spectral Ranges ◽  
Bias Terms

Ratio transformation methods are widely used for image fusion of high-resolution optical satellites. The premise for the use the ratio transformation is that there is a zero-bias linear relationship between the panchromatic band and the corresponding multi-spectral bands. However, there are bias terms and residual terms with large values in reality, depending on the sensors, the response spectral ranges, and the land-cover types. To address this problem, this paper proposes a panchromatic and multi-spectral image fusion method based on the panchromatic spectral decomposition (PSD). The low-resolution panchromatic and multi-spectral images are used to solve the proportionality coefficients, the bias coefficients, and the residual matrixes. These coefficients are substituted into the high-resolution panchromatic band and decompose it into the high-resolution multi-spectral bands. The experiments show that this method can make the fused image acquire high color fidelity and sharpness, it is robust to different sensors and features, and it can be applied to the panchromatic and multi-spectral fusion of high-resolution optical satellites.

Magnetic Field Tunable Electromechanical Resonance Properties of Magnetoelectric Bilayer

2015 ◽  
Vol 233-234 ◽  
pp. 349-352 ◽  
Author(s):  
Roman V. Petrov ◽  
Vladimir M. Petrov ◽  
Denis V. Kovalenko ◽  
Gennady A. Semenov ◽  
Mirza I. Bichurin
Keyword(s):  
Magnetic Field ◽  
Transmission Coefficient ◽  
Resonance Region ◽  
Bias Field ◽  
Zero Bias ◽  
Microwave Frequencies ◽  
Ac Electric Field ◽  
Resonance Properties ◽  
Variation Range ◽  
Electromechanical Resonance

The present paper focuses on the magnetoelectric coupling in dimensionally graded ferrite-piezoelectric bilayers in the electromechanical resonance region. Using the bilayer as a transducer which converts the ac magnetic field into an ac electric field shows that the transmission coefficient equals approximately -83 dB for zero bias magnetic field and -44 dB for bias field of 340 Oe. Thus, applying the DC field enables one to obtain the transmission coefficient variation range of 39 dB for the investigated structure. The phenomenon is of importance for the realization of multifunctional magnetoelectric devices including sensors and transducers operating at microwave frequencies.

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