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Temperature-Dependent Asymmetry of Anisotropic Magnetoresistance in Silicon p-n Junctions.

Yang DZ, Wang T, Sui WB, Si MS, Guo DW, Shi Z, Wang FC, Xue DS - Sci Rep (2015)

Bottom Line: More interestingly, in contrast with other materials, the lineshape of anisotropic magnetoresistance in silicon p-n junctions significantly depends on temperature.As temperature decreases from 293 K to 100 K, the width of peak shrinks from 90° to 70°.Therefore, the observed temperature-dependent asymmetry of magnetoresistance is proved to be a direct consequence of the spatial configuration evolution of space charge region with temperature.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Magnetism and Magnetic materials of Ministry of Education, Lanzhou University, Lanzhou 730000, China.

ABSTRACT
We report a large but asymmetric magnetoresistance in silicon p-n junctions, which contrasts with the fact of magnetoresistance being symmetric in magnetic metals and semiconductors. With temperature decreasing from 293 K to 100 K, the magnetoresistance sharply increases from 50% to 150% under a magnetic field of 2 T. At the same time, an asymmetric magnetoresistance, which manifests itself as a magnetoresistance voltage offset with respect to the sign of magnetic field, occurs and linearly increases with magnetoresistance. More interestingly, in contrast with other materials, the lineshape of anisotropic magnetoresistance in silicon p-n junctions significantly depends on temperature. As temperature decreases from 293 K to 100 K, the width of peak shrinks from 90° to 70°. We ascribe these novel magnetoresistance to the asymmetric geometry of the space charge region in p-n junction induced by the magnetic field. In the vicinity of the space charge region the current paths are deflected, contributing the Hall field to the asymmetric magnetoresistance. Therefore, the observed temperature-dependent asymmetry of magnetoresistance is proved to be a direct consequence of the spatial configuration evolution of space charge region with temperature.

No MeSH data available.


The linear relationship between the asymmtric features and the increment of MR voltage.(a) The FWHM offsets for peak and valley increases linearly with the increment of MR voltage for H = 0 and 2 T. (b) The peak amplitude offsets for θ = 90 and 270° increases linearly with the increment of MR voltage for H = 0 and 2 T.
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f3: The linear relationship between the asymmtric features and the increment of MR voltage.(a) The FWHM offsets for peak and valley increases linearly with the increment of MR voltage for H = 0 and 2 T. (b) The peak amplitude offsets for θ = 90 and 270° increases linearly with the increment of MR voltage for H = 0 and 2 T.

Mentions: In Fig. 3, we show the correlation of the two asymmetric behaviors with the increase MR voltage induced by magnetic field. Here we introduce two parameters ΔθFWHM and ΔVPeak to characterize these two types of asymmetric effects. The ΔθFWHM = θFWHM(180°) − θFWHM(90°), which is defined as the angle difference of FWHM between the valley (θ = 180°) and peak (θ = 90°) in Fig. 2a. The ΔVPeak = VPeak-L(90°) − VPeak-R(90°), which is defined as the voltage offset between the Peak-L (θ = 90°) and Peak-R (θ = 270°) in Fig. 2a. Interestingly, one can see that the two asymmetry parameters ΔθFWHM and ΔVPeak both linearly increase with the increasing MR effect, as shown in Fig. 3a,b, respectively. By linearly fitting the data, the offsets are −0.14 V and −20.4° for ΔVPeak and ΔθFWHM respectively, which are close to zeros. The proportional behaviors indicate that the asymmetry MR effects stems from the same mechanism of the large MR effect in p-n junctions.


Temperature-Dependent Asymmetry of Anisotropic Magnetoresistance in Silicon p-n Junctions.

Yang DZ, Wang T, Sui WB, Si MS, Guo DW, Shi Z, Wang FC, Xue DS - Sci Rep (2015)

The linear relationship between the asymmtric features and the increment of MR voltage.(a) The FWHM offsets for peak and valley increases linearly with the increment of MR voltage for H = 0 and 2 T. (b) The peak amplitude offsets for θ = 90 and 270° increases linearly with the increment of MR voltage for H = 0 and 2 T.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555100&req=5

f3: The linear relationship between the asymmtric features and the increment of MR voltage.(a) The FWHM offsets for peak and valley increases linearly with the increment of MR voltage for H = 0 and 2 T. (b) The peak amplitude offsets for θ = 90 and 270° increases linearly with the increment of MR voltage for H = 0 and 2 T.
Mentions: In Fig. 3, we show the correlation of the two asymmetric behaviors with the increase MR voltage induced by magnetic field. Here we introduce two parameters ΔθFWHM and ΔVPeak to characterize these two types of asymmetric effects. The ΔθFWHM = θFWHM(180°) − θFWHM(90°), which is defined as the angle difference of FWHM between the valley (θ = 180°) and peak (θ = 90°) in Fig. 2a. The ΔVPeak = VPeak-L(90°) − VPeak-R(90°), which is defined as the voltage offset between the Peak-L (θ = 90°) and Peak-R (θ = 270°) in Fig. 2a. Interestingly, one can see that the two asymmetry parameters ΔθFWHM and ΔVPeak both linearly increase with the increasing MR effect, as shown in Fig. 3a,b, respectively. By linearly fitting the data, the offsets are −0.14 V and −20.4° for ΔVPeak and ΔθFWHM respectively, which are close to zeros. The proportional behaviors indicate that the asymmetry MR effects stems from the same mechanism of the large MR effect in p-n junctions.

Bottom Line: More interestingly, in contrast with other materials, the lineshape of anisotropic magnetoresistance in silicon p-n junctions significantly depends on temperature.As temperature decreases from 293 K to 100 K, the width of peak shrinks from 90° to 70°.Therefore, the observed temperature-dependent asymmetry of magnetoresistance is proved to be a direct consequence of the spatial configuration evolution of space charge region with temperature.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Magnetism and Magnetic materials of Ministry of Education, Lanzhou University, Lanzhou 730000, China.

ABSTRACT
We report a large but asymmetric magnetoresistance in silicon p-n junctions, which contrasts with the fact of magnetoresistance being symmetric in magnetic metals and semiconductors. With temperature decreasing from 293 K to 100 K, the magnetoresistance sharply increases from 50% to 150% under a magnetic field of 2 T. At the same time, an asymmetric magnetoresistance, which manifests itself as a magnetoresistance voltage offset with respect to the sign of magnetic field, occurs and linearly increases with magnetoresistance. More interestingly, in contrast with other materials, the lineshape of anisotropic magnetoresistance in silicon p-n junctions significantly depends on temperature. As temperature decreases from 293 K to 100 K, the width of peak shrinks from 90° to 70°. We ascribe these novel magnetoresistance to the asymmetric geometry of the space charge region in p-n junction induced by the magnetic field. In the vicinity of the space charge region the current paths are deflected, contributing the Hall field to the asymmetric magnetoresistance. Therefore, the observed temperature-dependent asymmetry of magnetoresistance is proved to be a direct consequence of the spatial configuration evolution of space charge region with temperature.

No MeSH data available.