First principles calculations of electrical conductivity and giant magnetoresistance of periodic multilayers and spin valves (invited)

1996 ◽  
Vol 79 (8) ◽  
pp. 5282 ◽  
Author(s):  
W. H. Butler ◽  
X.-G. Zhang ◽  
D. M. C. Nicholson ◽  
T. C. Schulthess ◽  
J. M. MacLaren
Keyword(s):  
Electrical Conductivity ◽  
First Principles ◽  
Giant Magnetoresistance ◽  
Spin Valves ◽  
First Principles Calculations

Where Should We Look For High Zt Materials: Suggestions From Theory.

2000 ◽  
Vol 626 ◽  
Author(s):  
M. Fornari ◽  
D. J. Singh ◽  
I. I. Mazin ◽  
J. L. Feldman
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
First Principles ◽  
Room Temperature ◽  
First Principles Calculations ◽  
High Electrical Conductivity ◽  
Bulk Materials ◽  
Low Thermal Conductivity ◽  
Computational Exploration ◽  
Single Material

ABSTRACTThe key challenges in discovering new high ZT thermoelectrics are understanding how the nearly contradictory requirements of high electrical conductivity, high thermopower and low thermal conductivity can be achieved in a single material and based on this identifying suitable compounds. First principles calculations provide a material specific microscopic window into the relevant properties and their origins. We illustrate the utility of the approach by presenting specific examples of compounds belonging to the class of skutterudites that are or are not good thermoelectrics along with the microscopic reasons. Based on our computational exploration we make a suggestion for achieving higher values of ZT at room temperature in bulk materials, namely n-type La(Ru,Rh)4Sb12 with high La-filling.

Conductivity and mixed conductivity of a novel dense diffusion barrier and the sensing properties of limiting current oxygen sensors

2020 ◽  
Vol 49 (20) ◽  
pp. 6682-6692 ◽  
Author(s):  
Ke Shan ◽  
Zhong-Zhou Yi ◽  
Xi-Tao Yin ◽  
Davoud Dastan ◽  
Hamid Garmestani
Keyword(s):  
Electrical Conductivity ◽  
Diffusion Barrier ◽  
First Principles ◽  
Oxygen Sensors ◽  
Limiting Current ◽  
First Principles Calculations ◽  
Mixed Conductivity ◽  
Sensing Properties

First-principles calculations were used to explore the effect of various Y-doping levels on the electrical conductivity of SrTiO3.

Mechanism of the Giant Magnetoresistance in UNiGa from First-Principles Calculations

1996 ◽  
Vol 77 (26) ◽  
pp. 5253-5256 ◽  
Author(s):  
V. N. Antonov ◽  
A. Ya. Perlov ◽  
P. M. Oppeneer ◽  
A. N. Yaresko ◽  
S. V. Halilov
Keyword(s):  
First Principles ◽  
Giant Magnetoresistance ◽  
First Principles Calculations

ZnGeSb2: a promising thermoelectric material with tunable ultra-high conductivity

2016 ◽  
Vol 18 (37) ◽  
pp. 26275-26283 ◽  
Author(s):  
P. C. Sreeparvathy ◽  
V. Kanchana ◽  
G. Vaitheeswaran ◽  
N. E. Christensen
Keyword(s):  
Electrical Conductivity ◽  
Relaxation Time ◽  
Thermoelectric Material ◽  
Power Factor ◽  
First Principles ◽  
High Conductivity ◽  
First Principles Calculations ◽  
High Electrical Conductivity

First principles calculations predict the promising thermoelectric material ZnGeSb2with a huge power factor (S2σ/τ) on the order of 3 × 1017W m−1K−2s−1, due to the ultra-high electrical conductivity scaled by a relaxation time of around 8.5 × 1025Ω−1m−1s−1, observed in its massive Dirac state.

Effect of oxygen vacancies on electrical conductivity of La0.5Sr0.5FeO3−δ from first-principles calculations

2020 ◽  
Vol 8 (9) ◽  
pp. 4784-4789 ◽  
Author(s):  
Yonghun Shin ◽  
Kyung-Yeon Doh ◽  
Seong Hun Kim ◽  
June Ho Lee ◽  
Hohan Bae ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
First Principles ◽  
Oxygen Vacancies ◽  
First Principles Calculations ◽  
Excess Electrons ◽  
Effect Of Oxygen

Metal to semiconductor transition by hole compensation of excess electrons from VO and localized VO state in La0.5Sr0.5FeO3−δ under low PO2.

scholarly journals Origin of the Dzyaloshinskii-Moriya Interactions in the Intermetallic RMn2Si2 ( R= La, Ce, Yb and Y) Materials: A DFT Study

2021 ◽  
Author(s):  
Widad Bazine ◽  
Najim TAHIRI ◽  
Omar Elbounagui ◽  
Hamid Ez-Zahraouy
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Density Of States ◽  
First Principles ◽  
Giant Magnetoresistance ◽  
Dft Study ◽  
Spin Orbit ◽  
First Principles Calculations ◽  
Strong Hybridization ◽  
Large Spin

Abstract The Dzyaloshinskii-Moriya interactions (DM) are investigated using first-principles calculations by means of the WIENNCM code, an implementation of the FP-LAPW method. The intermetallic RMn2Si2 (R = La, Ce, Yb, and Y) materials exhibit a large spin-orbit effect after the density of states; they found a strong hybridization between Mn-Si and Mn-R atoms. Also, show a large noncollinear magnetic configuration depending on the R atoms. By using ab-initio calculations, the RKKY effect is observed in the RMn2Si2 materials, which shows explicitly the existence of the giant magnetoresistance (GMR) in these materials. Explicitly, the mechanisms responsible for the magnetoelectric coupling are due to relatively the effect of the presence of the Dzyaloshinskii-Moriya term.

scholarly journals Ferromagnetism and giant magnetoresistance in zinc-blende FeAs monolayers embedded in semiconductor structures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Le Duc Anh ◽  
Taiki Hayakawa ◽  
Yuji Nakagawa ◽  
Hikari Shinya ◽  
Tetsuya Fukushima ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Curie Temperature ◽  
First Principles ◽  
Giant Magnetoresistance ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Semiconductor Structures ◽  
Zinc Blende ◽  
Quantum Ground States

AbstractMaterial structures containing tetrahedral FeAs bonds, depending on their density and geometrical distribution, can host several competing quantum ground states ranging from superconductivity to ferromagnetism. Here we examine structures of quasi two-dimensional (2D) layers of tetrahedral Fe-As bonds embedded with a regular interval in a semiconductor InAs matrix, which resembles the crystal structure of Fe-based superconductors. Contrary to the case of Fe-based pnictides, these FeAs/InAs superlattices (SLs) exhibit ferromagnetism, whose Curie temperature (TC) increases rapidly with decreasing the InAs interval thickness tInAs (TC ∝ tInAs−3), and an extremely large magnetoresistance up to 500% that is tunable by a gate voltage. Our first principles calculations reveal the important role of disordered positions of Fe atoms in the establishment of ferromagnetism in these quasi-2D FeAs-based SLs. These unique features mark the FeAs/InAs SLs as promising structures for spintronic applications.

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