MAGNETORESISTANCE AND HALL EFFECT IN ORIENTED SINGLE CRYSTAL SAMPLES OF n-TYPE INDIUM ANTIMONIDE

1961 ◽  
Vol 39 (3) ◽  
pp. 452-467 ◽  
Author(s):  
C. H. Champness
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Single Crystal ◽  
Hall Effect ◽  
Air Temperature ◽  
Indium Antimonide ◽  
Room Temperature ◽  
Magneto Resistance ◽  
Longitudinal Magnetoresistance ◽  
Oriented Single Crystal

Measurements have been made on the angular dependence of the magneto-resistance effect and the Hall effect on oriented n-type indium antimonide samples. The measurements were taken at room temperature and liquid air temperature using a magnetic field strength of about 5000 gauss. Besides evidence of inhomogeneity, the results show directional dependence of the longitudinal magnetoresistance. The largest value was found in the [Formula: see text] direction. This can be explained if, in addition to electrons at the central minimum, there is some filling of the [Formula: see text] minima in k space.

The theory of the magneto-resistance effects in polar semi-conductors

1955 ◽  
Vol 227 (1169) ◽  
pp. 241-251 ◽  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Hall Coefficient ◽  
Low Temperatures ◽  
Magneto Resistance

General expressions are obtained for the Hall coefficient and transverse magneto-resistance effect in polar semi-conductors, and the variation of these effects with temperature, magnetic field strength and degeneracy of the electrons is discussed. At low temperatures the magneto-resistance effect may become very large, contrary to the prediction of the freepath theory.

scholarly journals Температурная зависимость напряжения, вызванного спиновым током в гетероструктуре манганит/иридат

2021 ◽  
Vol 63 (9) ◽  
pp. 1321
Author(s):  
Т.А. Шайхулов ◽  
К.Л. Станкевич ◽  
К.И. Константинян ◽  
В.В. Демидов ◽  
Г.А. Овсянников
Keyword(s):  
Thin Film ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Hall Effect ◽  
Ferromagnetic Resonance ◽  
Room Temperature ◽  
Ferromagnetic Layer ◽  
Spin Current ◽  
Epitaxial Thin Film ◽  
Inverse Spin Hall Effect

The temperature dependence of the voltage induced by the spin current was studied in an epitaxial thin-film La0.7Sr0.3MnO3 / SrIrO3 heterostructure deposited on a single-crystal NdGaO3 substrate. The spin current was generated by microwave pumping under conditions of ferromagnetic resonance in the La0.7Sr0.3MnO3 ferromagnetic layer and was detected in the SrIrO3 layer due to inverse spin Hall effect. A significant increase of half-width of the spin current spectrum along with the rise of amplitude of the spin current upon cooling from room temperature (300 K) to 135 K were observed.

scholarly journals Room temperature giant magnetostriction in single-crystal nickel nanowires

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Anastasios Pateras ◽  
Ross Harder ◽  
Sohini Manna ◽  
Boris Kiefer ◽  
Richard L. Sandberg ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Single Crystal ◽  
Room Temperature ◽  
Magnetic Energy ◽  
Mechanical Energy ◽  
Three Dimensional ◽  
Local Strain ◽  
Nickel Nanowires ◽  
Giant Magnetostriction

Abstract Magnetostriction is the emergence of a mechanical deformation induced by an external magnetic field. The conversion of magnetic energy into mechanical energy via magnetostriction at the nanoscale is the basis of many electromechanical systems such as sensors, transducers, actuators, and energy harvesters. However, cryogenic temperatures and large magnetic fields are often required to drive the magnetostriction in such systems, rendering this approach energetically inefficient and impractical for room-temperature device applications. Here, we report the experimental observation of giant magnetostriction in single-crystal nickel nanowires at room temperature. We determined the average values of the magnetostrictive constants of a Ni nanowire from the shifts of the measured diffraction patterns using the 002 and 111 Bragg reflections. At an applied magnetic field of 600 Oe, the magnetostrictive constants have values of λ100 = −0.161% and λ111 = −0.067%, two orders of magnitude larger than those in bulk nickel. Using Bragg coherent diffraction imaging (BCDI), we obtained the three-dimensional strain distribution inside the Ni nanowire, revealing nucleation of local strain fields at two different values of the external magnetic field. Our analysis indicates that the enhancement of the magnetostriction coefficients is mainly due to the increases in the shape, surface-induced, and stress-induced anisotropies, which facilitate magnetization along the nanowire axis and increase the total magnetoelastic energy of the system.

scholarly journals Colossal Negative Magnetoresistance Effect in a La1.37Sr1.63Mn2O7 Single Crystal Grown by Laser-Diode-Heated Floating-Zone Technique

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 547
Author(s):  
Si Wu ◽  
Yinghao Zhu ◽  
Junchao Xia ◽  
Pengfei Zhou ◽  
Haiyong Ni ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Laser Diode ◽  
Room Temperature ◽  
Floating Zone ◽  
Magnetoresistance Effect ◽  
X Ray ◽  
Mr Effect ◽  
Distinct Features ◽  
The Magnetic Field

We have grown La 1.37 Sr 1.63 Mn 2 O 7 single crystals with a laser-diode-heated floating-zone furnace and studied the crystallinity, structure, and magnetoresistance (MR) effect by in-house X-ray Laue diffraction, X-ray powder diffraction, and resistance measurements. The La 1.37 Sr 1.63 Mn 2 O 7 single crystal crystallizes into a tetragonal structure with space group I4/mmm at room temperature. At 0 T, the maximum resistance centers around ∼166.9 K. Below ∼35.8 K, it displays an insulating character with an increase in resistance upon cooling. An applied magnetic field of B = 7 T strongly suppresses the resistance indicative of a negative MR effect. The minimum MR value equals −91.23% at 7 T and 128.7 K. The magnetic-field-dependent resistance shows distinct features at 1.67, 140, and 322 K, from which we calculated the corresponding MR values. At 14 T and 140 K, the colossal negative MR value is down to −94.04(5)%. We schematically fit the MR values with different models for an ideal describing of the interesting features of the MR value versus B curves.

scholarly journals The theory of the galvomagnetic effects in bismuth

1936 ◽  
Vol 155 (886) ◽  
pp. 653-663 ◽  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Air Temperature ◽  
Solid Solutions ◽  
Hall Coefficient ◽  
Specific Resistance ◽  
Large Change ◽  
Free Electrons ◽  
The Magnetic Field ◽  
Positive Holes

The change in the specific resistance of bismuth when subject to a magnetic field is far greater than that of most metals, e . g ., a field of 10 kilo-gauss, at liquid air temperature, increases the resistance of bismuth eightfold, whilst the same field causes an increase of only 0·1% in the resistance of silver. Besides the large change of resistance it is found that the Hall coefficient of bismuth is also much greater than of most metals, and shows a curious dependence upon on the magnetic field strength, as well as a very striking temperature dependence. In this paper these effects are considered on the basis of a theory previously of bismuth, and the properties of the dilute solid solutions of other elements in bismuth.* It was shown that in bismuth the relation between the structure and the available number of valency electrons was such that these electrons formed an almost closed group, or in other words an almost completely filled Brillouin zone. In such a case an electric current is carried by a number (in bismuth a very small number) of electrons, and an equal number of positive holes. By positive holes we mean the few vacant places which are left when a zone or energy band is almost completely filled. These vacancies behave like positive charges; their effective mass is, in general, smaller than that of free electrons.

WO3-Based Sensor Based on Hall Effect for NO2 Detection: Designed and Investigation

2010 ◽  
Vol 148-149 ◽  
pp. 1042-1046
Author(s):  
Jin Yang Lin ◽  
Yong Ai Zhang ◽  
Ling Jie Wang ◽  
Tai Liang Guo
Keyword(s):  
Magnetic Field ◽  
Response Time ◽  
Hall Effect ◽  
Tungsten Trioxide ◽  
Recovery Time ◽  
Room Temperature ◽  
Gas Sensing ◽  
Test Chamber ◽  
Tungsten Filament ◽  
Gas Sensing Properties

Novel tungsten oxide sensors were fabricated based on Hall Effect and their NO2 gas sensing properties were examined. Tungsten trioxide was grown by vapor evaporation of metal tungsten filament in an oxygen atmosphere. A WO3 thick film was deposited on the four Au electrode to be a WO3 sensor. The sensor was tested between magnetic field in a plastic test chamber. The gas sensing experiment revealed that at the NO2 concentration of 40 ppm, a sensitivity of 3.27, a response time of 36 s, and a recovery time of 45 s were observed at room-temperature. The effect of WO3 based on Hall Effect on the sensing characteristic is discussed.

Galvanomagnetic Properties of 3C-SiC/6H-SiC Heterostructures

2008 ◽  
Vol 600-603 ◽  
pp. 541-544
Author(s):  
Alexander A. Lebedev ◽  
Pavel L. Abramov ◽  
Nina V. Agrinskaya ◽  
Ven I. Kozub ◽  
Alexey N. Kuznetsov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hall Effect ◽  
Epitaxial Films ◽  
Epitaxial Layers ◽  
Temperature Range ◽  
Galvanomagnetic Properties ◽  
Magneto Resistance

3C-SiC epitaxial layers were grown by method of sublimation epitaxy in vacuum on 6HSiC substrates. It was done investigation of magneto resistance and Hall effect of 3C-SiC/6H-SiC heterostructures in temperature range 1,4 – 300 К. At helium temperatures it was founded low samples resistance and negative magneto-resistance in week magnetic field ( ~ 1 T). Analysis of obtained results shows, that low samples resistance can be connected with metal-isolation junction in 3C-SiC epitaxial films..

HOPPING CONDUCTIVITY IN ONE-DIMENSIONAL Ca3Co2O6 SINGLE CRYSTAL

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3289-3292 ◽  
Author(s):  
J. M. BROTO ◽  
B. RAQUET ◽  
H. RAKOTO ◽  
M. N. BAIBICH ◽  
S. LAMBERT ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Applied Magnetic Field ◽  
Low Temperatures ◽  
Electronic Conductivity ◽  
Magnetic Ordering ◽  
One Dimensional ◽  
Coulomb Gap ◽  
Hopping Conductivity ◽  
Magneto Resistance

We studied the electronic conductivity of the quasi-one dimensional Ca3Co2O6 single crystal. The results evidence a VRH conductivity with temperature-induced crossover between 1D (intra-chain) and 3D transport and the opening of a Coulomb gap in the d bands. At low temperatures, an applied magnetic field induces a large negative magneto-resistance (MR) independent from the 3D magnetic ordering. Both spin-dependent hopping and field-induced suppression of the Coulomb gap are discussed.

scholarly journals Scanning Magnetic Microscope Using A Hall-Effect Sensor for Images of Remanent Magnetization Fields

2019 ◽  
Author(s):  
Jefferson F. D. F. Araujo ◽  
Angela A. P. Correa ◽  
Elder Yokoyama ◽  
Andre L. A. dos Reis ◽  
Vanderlei C. Oliveira Jr. ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hall Effect ◽  
Spatial Resolution ◽  
Room Temperature ◽  
Rock Magnetism ◽  
Magnetization Distribution ◽  
Geological Samples ◽  
Thin Sections ◽  
Magnetic Carriers ◽  
Magnetic Microscopy

Scanning magnetic microscopy is a new tool that has recently been used to map magnetic fields with good spatial resolution and field sensitivity. This technology has great advantages over other instruments; for example, its operation does not require cryogenic technology, which reduces its operational cost and complexity. Here, we describe the construction of a customizing scanning magnetic microscope based on commercial Hall-effect sensors at room temperature that achieves a spatial resolution of 200 µm. Two scanning stages on the x- and y-axes of precision, consisting of two coupled actuators, control the position of the sample, and this microscope can operate inside or outside a magnetic shield. We obtained magnetic field sensitivities better than 521 nTrms/√Hz between 1 and 10 Hz, which correspond to a magnetic momentum sensitivity of 9.20 × 10–10 Am2. In order to demonstrate the capability of the microscopy, polished thin sections of geological samples, samples containing microparticles and magnetic nanoparticles were measured. For the geological samples, a theoretical model was adapted from the magnetic maps obtained by the equipment. Vector field maps are valuable tools for the magnetic interpretation of samples with a high spatial variability of magnetization. These maps can provide comprehensive information regarding the spatial distribution of magnetic carriers. In addition, this model may be useful for characterizing isolated areas over samples or investigating the spatial magnetization distribution of bulk samples at the micro and millimeter scales. As an auxiliary technique, a magnetic sweep map was created using Raman spectroscopy; this map allowed the verification of different minerals in the samples. This equipment can be useful for many applications that require samples that need to be mapped without a magnetic field at room temperature, including rock magnetism, the nondestructive testing of steel materials and the testing of biological samples. The equipment can not only be used in cutting-edge research but also serve as a teaching tool to introduce undergraduate, master's and Ph.D. students to the measurement methods and processing techniques used in scanning magnetic microscopy.

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