scholarly journals Low-Frequency Noise of Magnetic Sensors Based on the Anomalous Hall Effect in Fe–Pt Alloys

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3537 ◽  
Author(s):  
Yiou Zhang ◽  
Qiang Hao ◽  
Gang Xiao

We took advantage of the large anomalous Hall effect (AHE) in Fe–Pt ferromagnetic alloys and fabricated magnetic sensors for low-frequency applications. We characterized the low-frequency electronic noise and the field detectability of the FexPt100-x system with various thin film thicknesses and Fe concentrations. The noise source consisted of 1/f and Johnson noise. A large current density increased the 1/f noise but not the Johnson noise. We found that the field detectability of the optimized Fe–Pt thin film offers much better low-frequency performance than a highly sensitive commercial semiconductor Hall sensor. Anomalous Hall effect sensors are, therefore, good candidates for magnetic sensing applications.

2009 ◽  
Vol 105 (12) ◽  
pp. 124504 ◽  
Author(s):  
S. L. Rumyantsev ◽  
Sung Hun Jin ◽  
M. S. Shur ◽  
Mun-Soo Park

2011 ◽  
Vol 495 ◽  
pp. 108-111 ◽  
Author(s):  
Vasiliki P. Tsikourkitoudi ◽  
Elias P. Koumoulos ◽  
Nikolaos Papadopoulos ◽  
Costas A. Charitidis

The adhesion and mechanical stability of thin film coatings on substrates is increasingly becoming a key issue in device reliability as magnetic and storage technology driven products demand smaller, thinner and more complex functional coatings. In the present study, chemical vapor deposited Co and Co3O4thin films on SiO2and Si substrates are produced, respectively. Chemical vapor deposition is the most widely used deposition technique which produces thin films well adherent to the substrate. Co and Co3O4thin films can be used in innovative applications such as magnetic sensors, data storage devices and protective layers. The produced thin films are characterized using nanoindentation technique and their nanomechanical properties (hardness and elastic modulus) are obtained. Finally, an evaluation of the reliability of each thin film (wear analysis) is performed using the hardness to elastic modulus ratio in correlation to the ratio of irreversible work to total work for a complete loading-unloading procedure.


1999 ◽  
Vol 598 ◽  
Author(s):  
P. V. Necliudov ◽  
D. J. Gundlach ◽  
T. N. Jackson ◽  
S. L. Rumyantsev ◽  
M. S. Shur

ABSTRACTWe studied the low frequency noise in top-contact pentacene Thin Film Transistors (TFTs). The relative spectral noise density of the drain current fluctuations SI/I2 had a form of 1/f noise in the measured frequency range 1Hz - 3.5kHz.Our studies of the noise dependencies on the gate-source VGS and drain-source VDS voltages showed that the dependencies differed from those observed for conducting polymers and resembled those reported for crystalline Si n-MOSFETs.To compare the device noise level with those of other devices and materials, we extracted the Hooge parameter α. In order to calculate the total number of carriers we used a model simulating the device DC characteristics, similar to that for amorphous Si TFTs. The extracted Hooge parameter was 0.04. For an organic material this is an extremely small value, which is three orders of magnitude smaller that the Hooge parameter values reported for conducting polymers and only several times higher than the values for amorphous Si TFTs.


2007 ◽  
Vol 515 (19) ◽  
pp. 7556-7559 ◽  
Author(s):  
A. Boukhenoufa ◽  
C. Cordier ◽  
L. Pichon ◽  
B. Cretu

2015 ◽  
Vol 1120-1121 ◽  
pp. 424-428
Author(s):  
C.Y. Zou ◽  
Lai Sen Wang ◽  
Xiang Liu ◽  
Q.F. Zhang ◽  
Jun Bao Wang ◽  
...  

In this paper, we studied the dependence of temperature and weak localization (WL) effect on the anomalous Hall effect (AHE) in strong disordered and poorly crystallized metal Co thin film deposited by high-pressure magnetron sputtering. The temperature coefficients of resistivity is positive at high temperatures and becomes negative at low temperatures, which is the typical characteristic of weak localization effect in dirty metal regime due to the strong disorder. The saturation anomalous Hall resistivity (ρAxy) have no scaling relation between ρxy and ρxx in weak localization region with temperature below 50 K. In metal region, temperature ranged from 50 K to 300 K, the relation between ρAxy and ρxxis ρAxy=A+bρ2xx, which indicates that the AHE in this Co thin film is scattering-independence at high temperature. The results also shows that the WL effect have a significant impact on the AHE of the Co thin film at low temperature.


2017 ◽  
Vol 31 (19-21) ◽  
pp. 1740020
Author(s):  
Yuan Liu ◽  
Yun-Fei En ◽  
Wen-Xiao Fang

Low frequency noises in the p-type polycrystalline silicon thin film transistors are investigated. It shows a pure 1/f[Formula: see text] (with [Formula: see text] near one) noise behavior which can be explained by emission and trapping processes of carriers between trapping states. Subsequently, the gate voltage-dependent drain current noise power spectral densities closely follow the mobility fluctuation model, and the average Hooge’s parameter is then extracted. By considering traditional tunneling processes, the flat-band voltage spectral density is extracted and the concentration of traps in the grain boundary is calculated to be [Formula: see text]. By converting the frequency to tunneling depth of carriers in the gate oxide, the spatial distribution of gate oxide trapped charges are obtained. Finally, the distribution of localized states in the energy band is extracted. The experimental results show an exponential deep states and tail states distribution in the band gap while [Formula: see text] is about [Formula: see text], [Formula: see text] is [Formula: see text][Formula: see text]617 K, [Formula: see text] is [Formula: see text] and [Formula: see text] is [Formula: see text][Formula: see text]265 K.


Nanoscale ◽  
2018 ◽  
Vol 10 (21) ◽  
pp. 10041-10049 ◽  
Author(s):  
Shanna Zhu ◽  
Dechao Meng ◽  
Genhao Liang ◽  
Gang Shi ◽  
Peng Zhao ◽  
...  

A high-quality Bi2Se3/LaCoO3 heterostructure is fabricated as a new TI/FMI system for investigating a proximity-induced ferromagnetic phase in topological insulators.


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