Free-carrier Faraday rotation in InAsxSb1−x alloys

1968 ◽  
Vol 46 (10) ◽  
pp. 1199-1206 ◽  
Author(s):  
Eric H. van Tongerloo ◽  
John C. Woolley
Keyword(s):  
Matrix Element ◽  
Carrier Concentration ◽  
Faraday Rotation ◽  
Hall Coefficient ◽  
Room Temperature ◽  
Calculated Data ◽  
Free Carrier ◽  
Similar Data ◽  
The Matrix ◽  
Power Measurements

Room-temperature free-carrier Faraday rotation measurements in the wavelength range 6–25 μ and Hall-coefficient measurements have been made on polycrystalline n-type samples of InAsxSb1−x alloys of carrier concentration ~1017/cm3. Using these data and a Kane equation for the conduction band, values of the bottom of the band effective mass m0* have been determined over the whole alloy range. The results are compared with similar data from magnetothermoelectric power measurements and also with previously calculated data. From the m0* results, values of the square of the matrix element P2 have been calculated as a function of x.

scholarly journals Optical and Transport Properties of p-Type GaAs

2012 ◽  
Vol 36 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Mehnaz Sharmin ◽  
Shamima Choudhury ◽  
Nasrin Akhtar ◽  
Tahmina Begum
Keyword(s):  
Light Intensity ◽  
Carrier Concentration ◽  
Hall Coefficient ◽  
Hall Mobility ◽  
Room Temperature ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
Band Gap Energy ◽  
Hall Effect Measurements ◽  
P Type

Electrical properties such as electrical resistivity, Hall coefficient, Hall mobility, carrier concentration of p-type GaAs samples were studied at room temperature (300 K). Resistivity was  found to be of the order of 5.6 × 10-3?-cm. The Hall coefficient (RH) was calculated to be 7.69 × 10-1cm3/C and Hall mobility (?H) was found to be 131cm2/V-s at room temperature from Hall effect   measurements. Carrier concentration was estimated to be 8.12 × 1018/cm3 and the Fermi level was calculated directly from carrier density data which was 0.33 eV. Photoconductivity measurements  were carried on by varying sample current, light intensity and temperature at constant chopping     frequency 45.60 Hz in all the cases mentioned above. It was observed that within the range of sample current 0.1 - 0.25mA photoconductivity remains almost constant at room temperature 300K and it was found to be varying non-linearly with light intensity within the range 37 - 12780 lux. Photoconductivity was observed to be increasing linearly with temperature between 308 and 428 K. Absorption coefficient (?) of the samples has been studied with variation of wavelength (300 -  2500 nm). The value of optical band gap energy was calculated between 1.34 and 1.41eV for the material from the graph of (?h?)2 plotted against photon energy. The value of lattice parameter (a) was found to be 5.651 by implying X-ray diffraction method (XRD).DOI: http://dx.doi.org/10.3329/jbas.v36i1.10926Journal of Bangladesh Academy of Sciences, Vol. 36, No. 1, 97-107, 2012 

Study of doping in GaAs layers by local probe techniques: micro-Raman, micro-photoluminescence and cathodoluminescence

2002 ◽  
Vol 738 ◽  
Author(s):  
Angel M. Ardila ◽  
O. Martínez ◽  
M. Avella ◽  
Luis F. Sanz ◽  
J. Jiménez ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Room Temperature ◽  
Free Carrier ◽  
Si Substrates ◽  
Hydrodynamic Approach ◽  
Fitting Method ◽  
Cathodoluminescence Spectroscopy ◽  
Conformal Method ◽  
Raman Modes ◽  
Homoepitaxial Layers

ABSTRACTThe free carrier concentration of GaAs layers grown by MOCVD either on GaAs or Si substrates, by the conformal method in the last case, was obtained from the micro-Raman spectra using the hydrodynamic approach to fit the LO phonon-plasmon coupled Raman modes. The results on homoepitaxial layers were used as a calibration of the fitting method. The measurements in the selectively doped conformal layers were then compared with data obtained by micro-photoluminescence and cathodoluminescence spectroscopy and imaging. The doping data are compared with those deduced from the room temperature micro-photoluminescence and cathodolumiescence spectra.

The conduction bands in 6H and 15R silicon carbide I. Hall effect and infrared Faraday rotation measurements

1967 ◽  
Vol 299 (1458) ◽  
pp. 383-392 ◽  
Keyword(s):  
Silicon Carbide ◽  
Hall Effect ◽  
Faraday Rotation ◽  
Hall Coefficient ◽  
Experimental Error ◽  
Room Temperature ◽  
Symmetry Axis ◽  
Conduction Bands ◽  
Axis Of Symmetry ◽  
Made In

Measurements of infrared Faraday rotation and Hall Effect have been made in a number of specimens belonging to the 6H and 15H polytypes of silicon carbide. Within experimental error the Hall coefficient in these samples was found to be isotropic and it is concluded that the conduction band extrema in both polytypes are most probably located on the symmetry axis. For this model the Faraday rotation results give the effective mass appropriate to directions perpendicular to the axis of symmetry as 0.25±0.02 m 0 in the 6H polytype and 0.28 ± 0.02 m 0 in the 15R polytype. Considerable care was required to ensure that the specimens used were uniform in carrier concentration and free from serious crystallographic faults; the precautions taken to meet these requirements and in particular the avoidance of one frequently occurring crystallographic imperfection are described in some detail. All the measurements were made at room temperature.

P-Type Transparent Conductivity of Cu1-xAlS2 (x = 0 ~ 0.08)

2008 ◽  
Vol 368-372 ◽  
pp. 666-668 ◽  
Author(s):  
Min Ling Liu ◽  
Fu Qiang Huang ◽  
Li Dong Chen
Keyword(s):  
Optical Properties ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Hall Coefficient ◽  
Hall Mobility ◽  
Room Temperature ◽  
Electrical And Optical Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

A series of Cu1-xAlS2 (x = 0 ~ 0.08) bulk samples were synthesized by spark plasma sintering. The electrical and optical properties were investigated. P-type conductions for all samples were confirmed by both positive Seebeck coefficient and Hall coefficient. Bulk undoped CuAlS2 had a high conductivity of about 0.9 S/cm with a large band gap of 3.4 eV at room temperature. For vacancy-doped in Cu site, the carrier concentration was highly enhanced, reaching 1.7 × 1019 cm-3 for 8 mol% doped sample, and without decreasing the bang gap. The introduction of vacancies destroys the continuity of Cu-S network, which decreases the Hall mobility.

Electron scattering in InAsxSb1−x alloys

1968 ◽  
Vol 46 (10) ◽  
pp. 1191-1198 ◽  
Author(s):  
Marcel J. Aubin ◽  
John C. Woolley
Keyword(s):  
Magnetic Field ◽  
Electron Scattering ◽  
Faraday Rotation ◽  
Hall Coefficient ◽  
Fermi Energy ◽  
Room Temperature ◽  
Zero Field ◽  
Scattering Mechanism ◽  
Scattering Parameter ◽  
The Magnetic Field

Room-temperature measurements of the thermoelectric power α and Hall coefficient R have been made as a function of the magnetic field B on polycrystalline n-type samples of InAsxSb1−x, alloys of carrier concentration ~1017/cm3. Hence saturation values α∞ and R∞ and zero-field values α∞ and R∞ have been determined. Using these values of α∞ and α∞ and assuming a Kane model for the conduction band, values have been determined for the Fermi energy EF and the scattering parameter s over the whole alloy range. In all cases, the value of s is close to 0.5, indicating that the dominant scattering mechanism in the alloys is piezoelectric scattering. From the EF and R∞ data, values of the bottom of the band effective mass have been calculated and these are compared with similar values obtained from Faraday rotation results.

Calculation of intrinsic carrier concentration in tellurium taking anisotropy into account

1976 ◽  
Vol 54 (9) ◽  
pp. 967-969 ◽  
Author(s):  
C. H. Champness
Keyword(s):  
Electrical Conductivity ◽  
Carrier Concentration ◽  
Hall Coefficient ◽  
Room Temperature ◽  
Intrinsic Carrier Concentration ◽  
Transverse Magnetoresistance

The intrinsic carrier concentration in tellurium is calculated at room temperature from measured values of electrical conductivity, Hall coefficient, and transverse magnetoresistance, taking anisotropy into account in a simple way. The model assumes one value of mobility parallel and another perpendicular to the c axis for both the electrons and holes.

Transport Properties of n Type Cd3−xZnxAs2 Alloys

1975 ◽  
Vol 53 (14) ◽  
pp. 1333-1337 ◽  
Author(s):  
M. J. Aubin
Keyword(s):  
Matrix Element ◽  
Transport Properties ◽  
Room Temperature ◽  
Scattering Parameter ◽  
Type Analysis ◽  
The Matrix ◽  
Lattice Vacancies

Measurements of the Hall and magneto-Seebeck effects were performed on polycrystalline Cd3−xZnxAs2 alloys at room temperature. The range of x considered here (0 to 1) is characterized by samples which are normally n type. Analysis of the data with Kane's model gives a minimum of the matrix element P at x = 0.6 which is interpreted as the manifestation of the band crossover suggested by Wagner et at. The scattering parameter also exhibits a minimum but at x ~ 0.2. A possible explanation may involve the manner in which the zinc atoms occupy the lattice vacancies.

Conduction bands of GaSb

1969 ◽  
Vol 47 (3) ◽  
pp. 241-247 ◽  
Author(s):  
Eric H. van Tongerloo ◽  
John C. Woolley
Keyword(s):  
Single Crystal ◽  
Faraday Rotation ◽  
Room Temperature ◽  
Free Carrier ◽  
Temperature Data ◽  
Energy Separation ◽  
Mass Ratio ◽  
Scattering Parameter ◽  
Conduction Bands ◽  
Effective Mass Ratio

Room temperature measurements of free-carrier Faraday rotation have been made on four different single-crystal n-type tellurium-doped samples of GaSb which had been used previously in magnetoresistance measurements. From the combined results for each specimen, values have been calculated for the energy separation of the (000) and [Formula: see text] conduction band minima, ΔE, and the transverse effective-mass ratio of the [Formula: see text] electrons, m1t/m. It is found that ΔE is a function of tellurium content. The value of ΔE at 4.2 °K for an intrinsic sample is hence found to be 0.078 eV. The values obtained for m1t/m, the variation of ΔE with tellurium content (dΔE/dy), and the temperature coefficient of ΔE (dΔE/dT) depend upon the value of the scattering parameter s assumed in the analysis of the room-temperature data. It is shown that the correct value of s lies in the range 0.5 to 1.0 and this gives values for m1t/m = 0.110 and dΔEdy = 0.50 eV/atomic % Te, while dΔE/dT probably lies in the range 0 to −2 × 10−5 eV/°K.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

ALCHEMI of B2-Ordered Fe50Al45Me5 alloys

1996 ◽  
Vol 54 ◽  
pp. 548-549
Author(s):  
Ian M. Anderson
Keyword(s):  
Room Temperature ◽  
Iron Aluminide ◽  
Low Density ◽  
Intermetallic Alloys ◽  
Practical Applications ◽  
Alloying Additions ◽  
Site Distribution ◽  
Good Corrosion Resistance ◽  
Room Temperature Ductility ◽  
The Matrix

B2-ordered iron aluminide intermetallic alloys exhibit a combination of attractive properties such as low density and good corrosion resistance. However, the practical applications of these alloys are limited by their poor fracture toughness and low room temperature ductility. One current strategy for overcoming these undesirable properties is to attempt to modify the basic chemistry of the materials with alloying additions. These changes in the chemistry of the material cannot be fully understood without a knowledge of the site-distribution of the alloying elements. In this paper, the site-distributions of a series of 3d-transition metal alloying additions in B2-ordered iron aluminides are studied with ALCHEMI.A series of seven alloys of stoichiometry Fe50AL45Me5, with Me = {Ti, V, Cr, Mn, Co, Ni, Cu}, were prepared with identical heating cycles. Microalloying additions of 0.2% B and 0.1% Zr were also incorporated to strengthen the grain boundaries, but these alloying additions have little influence on the matrix chemistry and are incidental to this study.

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