Experimental uniaxial stress and strain derivatives of the Fermi surface of rhenium

1980 ◽  
Vol 58 (8) ◽  
pp. 1191-1199 ◽  
Author(s):  
E. Fawcett ◽  
F. W. Holroyd ◽  
J. M. Perz
Keyword(s):  
Fermi Surface ◽  
Uniaxial Stress ◽  
Stress And Strain ◽  
Strong Anisotropy ◽  
Quantum Oscillations ◽  
Band Structure Calculations ◽  
Landau Quantum ◽  
Derivatives Of ◽  
Structure Calculations ◽  
The Magnetic Field

The derivatives of the areas of extremal orbits on all the small sheets of the Fermi surface of rhenium, with respect to stress and strain along the hexad axis, have been determined from simultaneous measurements of Landau quantum oscillations in magnetostriction and torque, and also in sound velocity and torque. Strong anisotropy is observed in the stress derivatives of orbits in zones five and six as the direction of the magnetic field defining the normal to the orbit is varied; the anisotropy is most pronounced for orbits which come close to the line of degeneracy AL on the hexagonal Brillouin zone face. The derivatives of the small void in zone eight are found to be very large; this is consistent with the results of band structure calculations which show that this feature of the Fermi surface is very sensitive to small changes in the Fermi energy. Cyclotron effective masses for a number of orbits on the void have also been measured.

scholarly journals Fermi surface of the skutterudite CoSb3 : Quantum oscillations and band-structure calculations

2021 ◽  
Vol 103 (8) ◽  
Author(s):  
M. Naumann ◽  
P. Mokhtari ◽  
Z. Medvecka ◽  
F. Arnold ◽  
M. Pillaca ◽  
...  
Keyword(s):  
Band Structure ◽  
Fermi Surface ◽  
Quantum Oscillations ◽  
Band Structure Calculations ◽  
Structure Calculations

Uniaxial strain dependence of the Fermi surface of tungsten

1977 ◽  
Vol 55 (4) ◽  
pp. 344-355 ◽  
Author(s):  
D. J. Stanley ◽  
J. M. Perz ◽  
M. J. G. Lee ◽  
R. Griessen
Keyword(s):  
Fermi Surface ◽  
Uniaxial Stress ◽  
Cross Sectional ◽  
Quantum Oscillations ◽  
Scattering Phase ◽  
Point Determination ◽  
Derivatives Of ◽  
Homogeneous Strain ◽  
Good Agreement

The derivatives of five representative cross sectional areas of the Fermi surface of tungsten with respect to uniaxial stress and strain along the cube axes, are determined experimentally from simultaneous measurements of quantum oscillations in magnetostriction and torque, and also in sound velocity and torque. The results are resolved into two components, the dependence on volume-conserving tetragonal shear, and the dependence on isotropic dilation. The tetragonal shear dependence is found to be in generally good agreement with the results of KKR calculations based on a fit to the unstrained Fermi surface. The isotropic dilation dependence agrees well with hydrostatic pressure measurements; from these results, the volume derivatives of the scattering phase shifts are deduced. This work is the first step towards a point-by-point determination of the distortion of the Fermi surface of tungsten in a lattice subjected to an arbitrary homogeneous strain.

Experimental determination of the dilational strain dependence of the Fermi surface of white tin

1980 ◽  
Vol 58 (4) ◽  
pp. 484-496 ◽  
Author(s):  
D. K. Mak ◽  
J. M. Perz
Keyword(s):  
Fermi Surface ◽  
Experimental Determination ◽  
Elastic Moduli ◽  
Hydrostatic Stress ◽  
Cross Sectional ◽  
Quantum Oscillations ◽  
Simultaneous Measurements ◽  
Landau Quantum ◽  
Derivatives Of

The derivatives with respect to uniaxial elongational strain of the areas of representative orbits on all sheets of the Fermi surface of tetragonal white tin have been deduced from simultaneous measurements of the Landau quantum oscillations in elastic moduli and in torque. Strain derivatives have been determined for most known extremal cross-sectional areas normal to the [100], [110], and [001] symmetry axes; the anisotropy of the strain derivatives of several area branches, having normal directions in the (010) and (001) planes, has also been studied. Uniaxial and hydrostatic stress derivatives deduced from the strain derivatives have been found to be generally consistent with values obtained by other means.

scholarly journals High-order fractal states in graphene superlattices

2018 ◽  
Vol 115 (20) ◽  
pp. 5135-5139 ◽  
Author(s):  
R. Krishna Kumar ◽  
A. Mishchenko ◽  
X. Chen ◽  
S. Pezzini ◽  
G. H. Auton ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Zero Magnetic Field ◽  
High Magnetic Fields ◽  
High Electron ◽  
Flux Quantum ◽  
Quantum Oscillations ◽  
Electron Trajectories ◽  
Unit Fractions ◽  
Band Structure Calculations ◽  
Structure Calculations

Graphene superlattices were shown to exhibit high-temperature quantum oscillations due to periodic emergence of delocalized Bloch states in high magnetic fields such that unit fractions of the flux quantum pierce a superlattice unit cell. Under these conditions, semiclassical electron trajectories become straight again, similar to the case of zero magnetic field. Here, we report magnetotransport measurements that reveal second-, third-, and fourth-order magnetic Bloch states at high electron densities and temperatures above 100 K. The recurrence of these states creates a fractal pattern intimately related to the origin of Hofstadter butterflies. The hierarchy of the fractal states is determined by the width of magnetic minibands, in qualitative agreement with our band-structure calculations.

Hydrostatic pressure and uniaxial stress derivatives of the Fermi surface of rhenium

1983 ◽  
Vol 61 (10) ◽  
pp. 1428-1433 ◽  
Author(s):  
J. R. Anderson ◽  
F. W. Holroyd ◽  
J. M. Perz ◽  
J. E. Schirber ◽  
I. M. Templeton
Keyword(s):  
Transition Temperature ◽  
Hydrostatic Pressure ◽  
Fermi Surface ◽  
Cross Sections ◽  
Solid Helium ◽  
Uniaxial Stress ◽  
Superconducting Transition ◽  
Cross Sectional ◽  
Effective Masses ◽  
Derivatives Of

Derivatives with respect to hydrostatic pressure of extremal cross-sectional areas normal to [Formula: see text] of all closed sheets of the Fermi surface of rhenium have been determined by both fluid–helium and solid–helium phase shift techniques. Precise values of de Haas–van Alphen frequencies and effective masses have also been measured for these cross sections. In addition, uniaxial stress derivatives of the zone seven cross sections have been deduced from quantum oseillations in magnetostriction and torque. Previously observed anomalies in the pressure dependence of the superconducting transition temperature are interpreted in terms of the present results.

scholarly journals Fermi surface of PtCoO2 from quantum oscillations and electronic structure calculations

2020 ◽  
Vol 101 (19) ◽  
Author(s):  
F. Arnold ◽  
M. Naumann ◽  
H. Rosner ◽  
N. Kikugawa ◽  
D. Graf ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Fermi Surface ◽  
Electronic Structure Calculations ◽  
Quantum Oscillations ◽  
Structure Calculations

Uniaxial strain derivatives of the Fermi surface of copper

1983 ◽  
Vol 61 (2) ◽  
pp. 177-187 ◽  
Author(s):  
D. W. Ruesink ◽  
J. M. Perz
Keyword(s):  
Experimental Study ◽  
Tensile Stress ◽  
Fermi Surface ◽  
Shear Strain ◽  
Cross Sections ◽  
The Other ◽  
Quantum Oscillations ◽  
Self Consistent ◽  
Torque Values ◽  
Derivatives Of

From a comprehensive experimental study of quantum oscillations in magnetostriction and torque, values have been deduced for all nonvanishing tetragonal and angular shear strain derivatives for the five principal extremal cross sections of the Fermi surface of copper, viz., the neck and belly normal to [111], the dogsbone normal to [110], and the rosette and belly normal to [001]. It is found that the neck is most sensitive to angular shear strain, whereas the bellies are most affected by uniform dilation. For the other orbits the magnitudes of shear and dilation derivatives are comparable.The results are self-consistent and agree with the experimental tensile stress results of Shoenberg and Watts. Earlier magnetostriction results for the neck obtained by Aron and by Slavin can be brought into agreement with the present data by recalculating the former using the now accepted value for the neck effective mass. The present experimental derivatives are in qualitative agreement with the theoretical values calculated by Lee, except for the tetragonal shear derivative of the [001] belly, for which the theoretical value is about 50% higher than the experimental one. This discrepancy is not fully understood.

Uniaxial stress and strain derivatives of the Fermi-surface necks in gold

1987 ◽  
Vol 65 (1) ◽  
pp. 13-15 ◽  
Author(s):  
H. Klimker ◽  
J. M. Perz ◽  
M. J. G. Lee
Keyword(s):  
Tensile Stress ◽  
Fermi Surface ◽  
Uniaxial Stress ◽  
Uniaxial Tensile ◽  
Direct Tension ◽  
Pressure Derivative ◽  
Cross Sectional ◽  
Uniaxial Tensile Stress ◽  
Compression Data ◽  
Derivatives Of

Simultaneous measurements of quantum oscillations in magnetostriction and torque in a single crystal of gold have been used to determine precise values for the derivatives of the cross-sectional area of the [111] neck of the Fermi surface with respect to uniaxial tensile stress along the [110] and [Formula: see text] directions. Independent estimates of the derivative with respect to uniaxial tensile stress along [111] of the neck area have been deduced from appropriate combinations of the [110] and [Formula: see text] stress derivatives with the established hydrostatic-pressure derivative. These estimates are in excellent agreement, giving ∂ lnA111/∂σ111 = (11.5 ± 0.3) × 10−12cm2∙dyn−1 (1 dyn = 10 μN). This result is significantly larger than the result of early direct-tension measurements in gold, suggesting that the latter suffered from systematic error. The present result is consistent with, and more precise than, earlier magnetostriction and direct uniaxial compression data. The angular shear derivative ∂ ln A/∂γ = 5.56 ± 0.17, deduced from the present data, is slightly larger than the theoretical value of 4.80 ± 0.20 obtained from a relativistic Korringa–Kohn–Rostoker phase-shift calculation based a rigid spherical muffin-tin pseudopotential.

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