Conduction Band Parameters in GaSb from High-Temperature Transport Measurements

1972 ◽  
Vol 50 (11) ◽  
pp. 1068-1077 ◽  
Author(s):  
Joseph Basinski ◽  
Clarence C. Y. Kwan ◽  
John C. Woolley
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Conduction Band ◽  
Hall Coefficient ◽  
Electron Mobility ◽  
Band Model ◽  
Zero Field ◽  
A Value ◽  
Semiempirical Relation ◽  
Band Separation

Measurements of resistivity and Hall coefficient as a function of magnetic field (0–3.2 Wb/m2) and temperature (25–200 C) have been made on samples of Te-doped GaSb. The results have been analyzed in terms of a two-conduction-band model with minima at Γ1 and L1, using the method reported by Kwan et al. This analysis yields a value for the Γ1–L1 band separation of 0.097 ± 0.002 eV, when linearly extrapolated to 0 K, and a temperature coefficient of −3.4 × 10−5 eV/K. The measurements of the Hall coefficient at 0.87 Wb/m2 and the zero-field resistivity have been extended to 360 C. These data have been analyzed using a four-band model (Γ1, L1X1, and Γ15 V), thus giving the temperature dependence of electron mobility in the Γ1 and L1 bands. The electron mobility values for the L1 band have then been fitted to a semiempirical relation, obtained by assuming appropriate scattering mechanisms.

CONDUCTION BAND OF GaSb

1966 ◽  
Vol 44 (11) ◽  
pp. 2715-2728 ◽  
Author(s):  
H. B. Harland ◽  
J. C. Woolley
Keyword(s):  
Magnetic Fields ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Hall Effect ◽  
Conduction Band ◽  
Electron Concentration ◽  
Electron Mobility ◽  
Impurity Level ◽  
Energy Separation ◽  
A Value

Measurements of transverse magnetoresistaiice and Hall effect have been made on various single-crystal n-type samples of GaSb at magnetic fields of up to 2.4 W/m2 and temperatures in the range 4.2–300 °K. An analysis of the results gives values and the temperature dependence for electron concentration n and electron mobility μ for both (000) and [Formula: see text] minima of the conduction band, the energy separation ΔE of (000) and [Formula: see text] minima, and a value for the effective mass m1* of electrons in the [Formula: see text] minima. Values of ΔE0 = 0.084 eV, d(ΔE)/dT = +0.8 × 10−4 eV/°C and m1* = 0.43 me are obtained, while the ratios of the electron mobilities μ0/μ1 lie in the range 5–21. The total number of observed electrons in the two bands, n0 + n1, is found to vary with temperature, and this result is interpreted in terms of an impurity level above the (000) minimum.

Electron transport and conduction band structure of GaSb

1981 ◽  
Vol 59 (12) ◽  
pp. 1844-1850 ◽  
Author(s):  
Hyung Jae Lee ◽  
John C. Woolley
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Electrical Conductivity ◽  
Conduction Band ◽  
Room Temperature ◽  
Energy Gap ◽  
Band Model ◽  
Scattering Coefficients ◽  
Wide Range ◽  
Different Temperatures

Calculations have been made using the Fletcher and Butcher method in a three conduction band model to fit a wide range of experimental transport data for n-type samples of GaSb: viz. Hall coefficient and electrical conductivity as a function of temperature and as a function of pressure at room temperature, magnetoresistance as a function of magnetic field at different temperatures, and Nernst–Ettingshausen coefficients as a function of magnetic field. Various energy gap parameters and scattering coefficients have been taken as adjustable and values determined for these which give good fits to all of the experimental data. Values of mobility for each of the Γ, L, and X bands have then been calculated as a function of temperature.

Continuous Two-Dimensional Melting of Vortex-Solid in High Temperature Superconductors

1989 ◽  
Vol 169 ◽  
Author(s):  
N.-C. Yeh
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Defect Density ◽  
High Temperature Superconductors ◽  
Finite Size ◽  
Sample Thickness ◽  
Zero Field ◽  
Two Dimensional ◽  
Thermally Induced ◽  
Transport Studies

AbstractA model of continuous two-dimensional melting in the mixed state of high temperature superconductors is proposed. Two-dimensional melting sets in at a cross-over temperature Tx(H) below the three-dimensinal phase transition Tx(H) due to finite size effects, and Tx(H) is a function of the sample thickness (lc), applied magnetic field (H), and k(= λ/ξ) For a given zero-field transition temperature Tc0 and material properties, (such as defect density), the onset temperature of 2D-melting (Tx(H)) decreases with decreasing sample thickness and increasing magnetic field. In transport studies, thermally induced melting is further complicated by the depinning effect of high current densities.

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.

FIELD-INDUCED ANTIFERROMAGNETISM IN THE HIGH-TEMPERATURE SUPERCONDUCTOR La2-xSrxCuO4

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3197-3197
Author(s):  
B. LAKE ◽  
T. E. MASON ◽  
G. AEPPLI ◽  
K. LEFMANN ◽  
N. B. CHRISTENSEN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Normal State ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Field Measurements ◽  
Spin Fluctuations ◽  
Magnetic Interactions ◽  
Zero Field ◽  
Zero Resistance

There is strong evidence that magnetic interactions play a crucial role in the mechanism driving high-temperature superconductivity in cuprate superconductors. To investigate this we have done a series of neutron scattering measurements on La 2-x Sr x CuO 4 (LSCO) in an applied magnetic field. Below Tc the field penetrates the superconductor via an array of normal state metallic inclusions or vortices. Phase coherent superconductivity characterized by zero resistance sets in at the lower field-dependent irreversibility temperature (Tirr). We have measured optimally doped LSCO (x = 0.16, Tc = 38.5 K ) and under-doped LSCO ( x = 0.10, Tc = 29 K ); both have an enhanced antiferromagnetic response in a field. Measurements of the optimally doped system at H = 7.5 T show that sub-gap spin fluctuations first disappear with the loss of finite resistivity at Tirr, but then reappear at a lower temperature with increased lifetime and correlation length compared to the normal state. In the under-doped system elastic antiferromagnetism develops below Tc in zero field, and is significantly enchanced by application of a magnetic field. Phase coherent superconductivity is then established within the antiferromagnetic phase at Tirr; thus, the situation in under-doped LSCO is the reverse of that for the optimally doped LSCO where the zero-resistance state develops first before the onset of antiferromagnetism.

scholarly journals Magnetic field reveals vanishing Hall response in the normal state of stripe-ordered cuprates

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhenzhong Shi ◽  
P. G. Baity ◽  
J. Terzic ◽  
Bal K. Pokharel ◽  
T. Sasagawa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hall Coefficient ◽  
Normal State ◽  
High Field ◽  
Fundamental Property ◽  
Zero Field ◽  
Superconducting Transition ◽  
Underdoped Cuprates ◽  
Competing Orders

AbstractThe origin of the weak insulating behavior of the resistivity, i.e. $${\rho }_{xx}\propto {\mathrm{ln}}\,(1/T)$$ ρ x x ∝ ln ( 1 / T ) , revealed when magnetic fields (H) suppress superconductivity in underdoped cuprates has been a longtime mystery. Surprisingly, the high-field behavior of the resistivity observed recently in charge- and spin-stripe-ordered La-214 cuprates suggests a metallic, as opposed to insulating, high-field normal state. Here we report the vanishing of the Hall coefficient in this field-revealed normal state for all $$T\ <\ (2-6){T}_{{\rm{c}}}^{0}$$ T < ( 2 − 6 ) T c 0 , where $${T}_{{\rm{c}}}^{0}$$ T c 0 is the zero-field superconducting transition temperature. Our measurements demonstrate that this is a robust fundamental property of the normal state of cuprates with intertwined orders, exhibited in the previously unexplored regime of T and H. The behavior of the high-field Hall coefficient is fundamentally different from that in other cuprates such as YBa2Cu3O6+x and YBa2Cu4O8, and may imply an approximate particle-hole symmetry that is unique to stripe-ordered cuprates. Our results highlight the important role of the competing orders in determining the normal state of cuprates.

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