Intrinsic Gap States in Semiconductors with Inverted Band Structure: Comparison of SnTe vs PbTe Nanocrystals

2019 ◽  
Vol 123 (18) ◽  
pp. 11974-11981
Author(s):  
Roman Vaxenburg ◽  
Janice E. Boercker ◽  
Danielle L. Woodall ◽  
Chase T. Ellis ◽  
C. Stephen Hellberg ◽  
...  
Keyword(s):  
Band Structure ◽  
Structure Comparison ◽  
Gap States

Band Structure Calculations and Magnetic Relaxation in Correlated Semiconductors FeSb2 and RuSb2

2009 ◽  
Vol 152-153 ◽  
pp. 287-290 ◽  
Author(s):  
A.A. Gippius ◽  
K.S. Okhotnikov ◽  
M. Baenitz ◽  
A.V. Shevelkov
Keyword(s):  
Band Structure ◽  
Magnetic Relaxation ◽  
Narrow Band ◽  
Relaxation Mechanism ◽  
Activation Mechanism ◽  
Oxidation Number ◽  
Band Structure Calculations ◽  
Gap States ◽  
Structure Calculations ◽  
Behavior Characteristic

A comparative study of electronic properties of the two isostructural narrow-band semiconductors FeSb2 and RuSb2 by means of experimental NQR spectroscopy as well as theoretical ab-initio band structure calculations is presented. The temperature dependence of 1/T1 consists of two distinct intervals: above 40 K (HT) with activated behavior for FeSb2 with D/kB @ 450 K and below 40 K (LT) with smooth maximum at 10 K. Here the relaxation is governed by in-gap states. We propose the model of inherent Sb-deficiency (as prepared non-stoichiometry) of both FeSb2 and RuSb2 as a possible reason of the in-gap states. This results in creation of a small portion of Fe (Ru) ions possessing formal oxidation number +3 with d5 configuration and forming narrow energy level of localized S = ½ spins near the bottom of the conduction band. Due to much higher gap value in RuSb2, the activation mechanism for RuSb2 in the HT range is inefficient and the 1/T1 dependence in the HT range is more close to T2 behavior characteristic for phonon relaxation mechanism by two-phonon (Raman) scattering.

Gap states in a-SiC from optical measurements and band structure models

2002 ◽  
Vol 14 (8) ◽  
pp. 1799-1812 ◽  
Author(s):  
V I Ivashchenko ◽  
V I Shevchenko ◽  
G V Rusakov ◽  
A S Klymenko ◽  
V M Popov ◽  
...  
Keyword(s):  
Band Structure ◽  
Optical Measurements ◽  
Gap States

The effect of oxygen vacancy on holes-induced d0 magnetism in CaTiO3 and CaZrO3

2015 ◽  
Vol 29 (24) ◽  
pp. 1550137
Author(s):  
Xiao-Xi Zheng ◽  
Dan Wang ◽  
Li-Ming Tang ◽  
Ke-Qiu Chen
Keyword(s):  
Oxygen Vacancy ◽  
Band Structure ◽  
Magnetic Moment ◽  
First Principles ◽  
First Principles Calculations ◽  
La Doping ◽  
Titanium Zirconium ◽  
Effect Of Oxygen ◽  
D0 Magnetism ◽  
Gap States

Using the first-principles calculations, the holes-induced [Formula: see text] magnetism associated with oxygen vacancy [Formula: see text] in [Formula: see text] and [Formula: see text] has been investigated. To obtain holes, the divalent calcium and tetravalent IVB-group ions are replaced respectively by the monovalent alkali, IB-group and trivalent III-group ions. It is found that the [Formula: see text] can enhance the magnetic moment of few acceptors-doped [Formula: see text], whereas it enhances the magnetic moment in most acceptor-doped [Formula: see text] except for La doping. Mainly, it is because the [Formula: see text] gives rise to no gap-states in [Formula: see text] but generates gap-states in [Formula: see text]. Based on the similar effect of [Formula: see text] on the band structure in [Formula: see text] or in [Formula: see text] (X = Ca, Sr, Ba), we suggest that there exists a similar effect of [Formula: see text] on [Formula: see text] magnetism in acceptor-doped alkaline titanium (zirconium) perovskites.

Band structure and packet-martensite structure. Comparison of evolution paths

1992 ◽  
Vol 35 (10) ◽  
pp. 906-911 ◽  
Author(s):  
�. V. Kozlov ◽  
L. A. Teplyakova ◽  
N. A. Popova ◽  
Y. F. Ivanov ◽  
D. V. Lychagin ◽  
...  
Keyword(s):  
Band Structure ◽  
Structure Comparison ◽  
Packet Martensite ◽  
Martensite Structure

ELECTRONIC STRUCTURE OF TRANSITION METAL COMPOUNDS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 324-332
Author(s):  
S. HÜFNER
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Band Structure ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Transition Metal Compounds ◽  
Exact Nature ◽  
Metal Compounds ◽  
Basic Features ◽  
Gap States

The basic features of the electronic structure of transition metal oxides is discussed. It is found that the bands of the anions are well understood whereas the exact nature of the d-bands is still uncertain. There is a competition between local excitonic like excitations and excitations which reflect with some renormalization the band structure. The nature of gap states in NiO is discussed.

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