Change of the de Haas – van Alphen frequency of potassium with pressure

1980 ◽  
Vol 58 (3) ◽  
pp. 370-375 ◽  
Author(s):  
Z. Altounian ◽  
W. R. Datars
Keyword(s):  
Band Structure ◽  
Fermi Surface ◽  
Pressure Dependence ◽  
Charge Density Wave ◽  
Energy Gap ◽  
Density Wave ◽  
Surface Anisotropy ◽  
Band Structure Calculations ◽  
Structure Calculations ◽  
Fermi Surface Anisotropy

The pressure dependence of the de Haas – van Alphen frequency in oriented potassium samples has been investigated with pressures up to 4.6 kbar. The change of frequency with pressure is less than that expected from free-electron scaling and the Fermi surface anisotropy increases from 0.13% at zero pressure to 0.47% at 4 kbar. These results are discussed in terms of band structure calculations and the charge density wave (CDW) model of potassium. The CDW energy gap changes with pressure for the CDW model to be applicable.

Magnetoresistance in pulsed fields, band structure calculations and charge-density wave instability in (TSeT)2Cl

1995 ◽  
Vol 70 (1-3) ◽  
pp. 1279-1280 ◽  
Author(s):  
F. Goze ◽  
A. Audouard ◽  
L. Brossard ◽  
V.N. Laukhin ◽  
J.P. Ulmet ◽  
...  
Keyword(s):  
Band Structure ◽  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Wave Instability ◽  
Band Structure Calculations ◽  
Pulsed Fields ◽  
Structure Calculations

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

Reversible Iodine Intercalation into Tungsten Ditelluride

2020 ◽  
Author(s):  
Patrick Schmidt ◽  
Philipp Schneiderhan ◽  
Markus Ströbele ◽  
Carl P. Romao ◽  
H.-Jürgen Meyer
Keyword(s):  
Band Structure ◽  
Density Functional ◽  
Density Wave ◽  
Fused Silica ◽  
Orthorhombic Space Group ◽  
Functional Theory ◽  
Band Structure Calculations ◽  
Axis Length ◽  
A Charge ◽  
Structure Calculations

The new compound WTe2I was prepared by a reaction of WTe2 with iodine in a fused silica vessel at temperatures between 40 and 200 °C. Iodine atoms are intercalated into the van der Waals gap between tungsten ditelluride layers. As a result, the WTe2 layer separation and therefore the c-axis length is significantly increased, and the orthorhombic space group is preserved. Iodine atoms form planar layers between each tungsten ditelluride layer. Due to oxidation by iodine the semi-metallic nature of WTe2 is changed, as shown by comparative band structure calculations for WTe2 and WTe2I based on density functional theory. The calculated phonon band structure of WTe2I suggests a charge density wave instability at low temperature.<br>

Reversible Iodine Intercalation into Tungsten Ditelluride

2020 ◽  
Author(s):  
Patrick Schmidt ◽  
Philipp Schneiderhan ◽  
Markus Ströbele ◽  
Carl P. Romao ◽  
H.-Jürgen Meyer
Keyword(s):  
Band Structure ◽  
Density Functional ◽  
Density Wave ◽  
Fused Silica ◽  
Orthorhombic Space Group ◽  
Functional Theory ◽  
Band Structure Calculations ◽  
Axis Length ◽  
A Charge ◽  
Structure Calculations

The new compound WTe2I was prepared by a reaction of WTe2 with iodine in a fused silica vessel at temperatures between 40 and 200 °C. Iodine atoms are intercalated into the van der Waals gap between tungsten ditelluride layers. As a result, the WTe2 layer separation and therefore the c-axis length is significantly increased, and the orthorhombic space group is preserved. Iodine atoms form planar layers between each tungsten ditelluride layer. Due to oxidation by iodine the semi-metallic nature of WTe2 is changed, as shown by comparative band structure calculations for WTe2 and WTe2I based on density functional theory. The calculated phonon band structure of WTe2I suggests a charge density wave instability at low temperature.<br>

The Fermi surface of beryllium

1964 ◽  
Vol 282 (1391) ◽  
pp. 521-546 ◽  
Keyword(s):  
Band Structure ◽  
Fermi Surface ◽  
Cross Section ◽  
Brillouin Zone ◽  
Field Direction ◽  
Pulsed Magnetic Fields ◽  
Hexagonal Symmetry ◽  
Band Structure Calculations ◽  
Structure Calculations ◽  
Good Agreement

The Fermi surface of beryllium has been determined experimentally by studying the de Haas–van Alphen effect of single crystals in pulsed magnetic fields. The de Haas–van Alphen frequency (proportional to the extremal area of the Fermi surface normal to the field) was measured as a function of field direction. Consideration of the hexagonal symmetry of the Brillouin zone (discussed in the Appendix) shows that only six distinct classes of fre­quency variation with field direction are possible, and these considerations are used to deduce the locations and forms of the various sheets of the Fermi surface. The Fermi surface is found to consist of hole and electron surfaces of equal volume (each containing 0∙162 carrier per atom). The hole surface is somewhat like a coronet, i. e. a ring of six smoothed tetrahedra joined by small necks lying in the central (0001) plane of the first double Brillouin zone, and the electron surface is a set of six roughly ellipsoidal surfaces (cigars) lying on the vertical edges of the second double zone. Detailed shapes and sizes are deduced for the coronet and cigars such that the extremal areas of cross-section are consistent to within 1 % of those obtained from the observed de Haas–van Alphen frequencies. No oscillations of frequency corresponding to the outer (0001) orbit round the coronet were, however, observed; a study of the field dependence of amplitude of the oscillations from the coupled orbit round the cigar shows that this absence can be explained by magnetic breakdown of the {101̄0} band gap. The model described is in good agreement with the predictions of recent band structure calculations, and is consistent with other experimental evidence.

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