Band Structure and Band-Gap Effects for Photoelectron Spin Polarization of Ferromagnetic Metals

1974 ◽  
Vol 37 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Tsuyoshi Murao
Keyword(s):  
Band Structure ◽  
Band Gap ◽  
Spin Polarization ◽  
Ferromagnetic Metals ◽  
Gap Effects

Acoustic band gap measurements in waveguides with periodic resonant structures

2005 ◽  
Vol 220 (9-10) ◽  
Author(s):  
John Ash ◽  
William M. Robertson
Keyword(s):  
Band Structure ◽  
Band Gap ◽  
Phase Information ◽  
One Dimensional ◽  
Resonant Structures ◽  
Amplitude Data ◽  
The One ◽  
Acoustic Dispersion ◽  
Gap Effects ◽  
Good Agreement

AbstractExperimental measurements, using an impulse response technique, are reported on a one-dimensional acoustic band gap system composed of a waveguide with a series of regularly spaced resonant structures. The amplitude data of the experimental results demonstrate the frequency and extent of the forbidden transmission bands and the phase information is analysed to determine the acoustic dispersion — the band structure — in the one-dimensional array. The results exhibit generally good agreement with previous theoretical analysis both in terms of the location of the forbidden transmission frequencies and in the form of the band structure. This simple system is a good candidate for the exploration of a number of postulated acoustic band gap effects.

Band Structure and Thermoelectric Properties of Ni(x)Zn(1-x)Fe2O4

2021 ◽  
Vol 317 ◽  
pp. 28-34
Author(s):  
Joon Hoong Lim
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Band Structure ◽  
Seebeck Coefficient ◽  
Band Gap ◽  
Thermoelectric Properties ◽  
Xrd Analysis ◽  
Valence Band Maximum ◽  
Solid State Method ◽  
Ni Content

Thermoelectric materials has made a great potential in sustainable energy industries, which enable the energy conversion from heat to electricity. The band structure and thermoelectric properties of Ni(x)Zn(1-x)Fe2O4 have been investigated. The bulk pellets were prepared from analytical grade ZnO, NiO and Fe2O3 powder using solid-state method. It was possible to obtain high thermoelectric properties of Ni(x)Zn(1-x)Fe2O4 by controlling the ratios of dopants and the sintering temperature. XRD analysis showed that the fabricated samples have a single phase formation of cubic spinel structure. The thermoelectric properties of Ni(x)Zn(1-x)Fe2O4 pellets improved with increasing Ni. The electrical conductivity of Ni(x)Zn(1-x)Fe2O4 pellets decreased with increasing Ni content. The electrical conductivity of Ni(x)Zn(1-x)Fe2O4 (x = 0.0) is (0.515 x10-3 Scm-1). The band structure shows that ZnxCu1-xFe2O4 is an indirect band gap material with the valence band maximum (VBM) at M and conduction band minimum (CBM) at A. The band gap of Ni(x)Zn(1-x)Fe2O4 increased with increasing Ni content. The increasing band gap correlated with the lower electrical conductivity. The thermal conductivity of Ni(x)Zn(1-x)Fe2O4 pellets decreased with increasing Ni content. The presence of Ni served to decrease thermal conductivity by 8 Wm-1K-1 over pure samples. The magnitude of the Seebeck coefficient for Ni(x)Zn(1-x)Fe2O4 pellets increased with increasing amounts of Ni. The figure of merit for Ni(x)Zn(1-x)Fe2O4 pellets and thin films was improved by increasing Ni due to its high Seebeck coefficient and low thermal conductivity.

CHANGES INDUCED IN THE SURFACE ELECTRONIC STRUCTURE OF Be(0001) AFTER Si ADSORPTION

2002 ◽  
Vol 09 (02) ◽  
pp. 687-691
Author(s):  
L. I. JOHANSSON ◽  
C. VIROJANADARA ◽  
T. BALASUBRAMANIAN
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Band Gap ◽  
Electronic Properties ◽  
Surface State ◽  
Core Level ◽  
Clean Surface ◽  
Core Level Spectrum ◽  
Surface Band ◽  
Surface Electronic Structure

A study of effects induced in the Be 1s core level spectrum and in the surface band structure after Si adsorption on Be(0001) is reported. The changes in the Be 1s spectrum are quite dramatic. The number of resolvable surface components and the magnitude of the shifts do decrease and the relative intensities of the shifted components are drastically different compared to the clean surface. The surface band structure is also strongly affected after Si adsorption and annealing. At [Formula: see text] the surface state is found to move down from 2.8 to 4.1 eV. The band also splits at around 0.5 Å-1 along both the [Formula: see text] and [Formula: see text] directions. At [Formula: see text] and beyond [Formula: see text] only one surface state is observed in the band gap instead of the two for the clean surface. Our findings indicate that a fairly small amount of Si in the outer atomic layers strongly modifies the electronic properties of these layers.

Energy and spin polarization analysis of near band gap photoemission in AlGaAs/GaAs heterostructures

1988 ◽  
Vol 38 (3) ◽  
pp. 458-461 ◽  
Author(s):  
F Ciccacci ◽  
H-J Drouhin ◽  
C Hermann ◽  
R Houdré ◽  
G Lampel ◽  
...  
Keyword(s):  
Band Gap ◽  
Spin Polarization ◽  
Polarization Analysis

Fabrication of Two-Dimensional Photonic Band Structure with Near-Infrared Band Gap

1994 ◽  
Vol 33 (Part 2, No. 10B) ◽  
pp. L1463-L1465 ◽  
Author(s):  
Kuon Inoue ◽  
Mitsuo Wada ◽  
Kazuaki Sakoda ◽  
Akio Yamanaka ◽  
Masaki Hayashi ◽  
...  
Keyword(s):  
Band Structure ◽  
Band Gap ◽  
Near Infrared ◽  
Two Dimensional ◽  
Photonic Band Structure ◽  
Infrared Band ◽  
Photonic Band
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