scholarly journals Robust Half-Metallic Character In KMnGe Half-Heusler Compound

2021 ◽  
Vol 1 (2) ◽  
pp. 9-17
Author(s):  
Timothy Chibueze ◽  
Fabian Ezema
Keyword(s):  
Energy Gap ◽  
Half Metallic ◽  
Spintronic Devices ◽  
Electronic Spin ◽  
Materials Research ◽  
Direct Band ◽  
Spin Injectors ◽  
Low Pressures

The search for spin injectors and spin sources in spintronic devices is a significant facet of materials research today. Consequently, half-Heusler (HAH) KMnGe alloy has been recommended as one such admissible materials. Herein, a rigorous examination of the structural, magnetic and electronic properties of HAH KMnGe alloy is done using ab initio method within the bolstered up rendition of the functional by Perdew and his group. Our result shows that HAH KmnGe alloy expresses type-1 and type-2 HAH  structural ground state at high and low pressures respectively, which may pose a challenge in application. Impressively, HAH KMnGe alloy exhibits half metallic characteristic with an indirect energy gap in the Γ-X symmetry k-point and direct band gap at X-point in the minority electronic spin states for type-1 and type-2 phase respectively. Our findings agree fundamentally with some previous findings in the literature and suggests that the HAH KMnGe alloy is a credible excellent spin source in future spintronic devices.

Robust Half-Metallic Character In KMnGe Half-Heusler Compound

2021 ◽  
Vol 1 (2) ◽  
pp. 9-17
Author(s):  
Chibueze T. C ◽  
Ezema F. I
Keyword(s):  
Energy Gap ◽  
Half Metallic ◽  
Spintronic Devices ◽  
Electronic Spin ◽  
Materials Research ◽  
Direct Band ◽  
Spin Injectors ◽  
Low Pressures

The search for spin injectors and spin sources in spintronic devices is a significant facet of materials research today. Consequently, half-Heusler (HAH) KMnGe alloy has been recommended as one such admissible materials. Herein, a rigorous examination of the structural, magnetic and electronic properties of HAH KMnGe alloy is done using ab initio method within the bolstered up rendition of the functional by Perdew and his group. Our result shows that HAH KmnGe alloy expresses type-1 and type-2 HAH  structural ground state at high and low pressures respectively, which may pose a challenge in application. Impressively, HAH KMnGe alloy exhibits half metallic characteristic with an indirect energy gap in the Γ-X symmetry k-point and direct band gap at X-point in the minority electronic spin states for type-1 and type-2 phase respectively. Our findings agree fundamentally with some previous findings in the literature and suggests that the HAH KMnGe alloy is a credible excellent spin source in future spintronic devices.

Structural and electronic properties of V- and Co-doped single-walled ZnONT(8,0): Transition from semiconducting to metallic and half-metallic states

2015 ◽  
Vol 29 (07) ◽  
pp. 1550068
Author(s):  
R. Taghavi Mendi ◽  
M. Majidiyan Sarmazdeh ◽  
S. M. Elahi ◽  
M. R. Abolhassani ◽  
A. Boochani ◽  
...  
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
First Principles Calculations ◽  
Half Metallic ◽  
Spintronic Devices ◽  
Zno Nanotube ◽  
Structural And Electronic Properties ◽  
Direct Band ◽  
Structure Density ◽  
Co Doped

In this paper, some structural and electronic properties of V - and Co -doped single-walled ZnO nanotube (8,0), such as cohesive energy, geometric structure, density of states and band structure were investigated using first principles calculations. Our results showed that, first, the pure SWZnONT(8,0) can be stable and second, doped SWZnONTs(8,0) by V and Co atoms are more stable than pure SWZnONT(8,0) and TM impurities distort the structure of nanotubes around the TM impurities. The electronic results showed that pure SWZnONT(8,0) have a direct band gap about 1.443 eV and it is semiconductor. While with substituting V and Co instead of Zn in nanotube, a transition occurs from semiconducting to metallic and half-metallic states which these doped nanotubes as well as their magnetic properties are qualified for using in spintronic devices.

Electronic and magnetic properties of bulk and surfaces half-Heusler alloy KCaB and its bulk thermoelectric properties

2021 ◽  
pp. 2150258
Author(s):  
Jabbar M. Khalaf Al-zyadi ◽  
Wed A. Abed ◽  
Ahmed Hamad Ati
Keyword(s):  
Magnetic Moment ◽  
Heusler Alloy ◽  
Density Functional ◽  
Energy Gap ◽  
Relaxation Effect ◽  
First Principles Calculation ◽  
Half Metallic ◽  
Text Type ◽  
Electronic Spin ◽  
Metallic Ferromagnet

This paper discusses the structural, electronic, magnetic, and half-metallic properties of half-Heusler alloy KCaB. First-principles calculation based on density functional theory is successfully used to determine properties at bulk and on the (111) and (001) surfaces of KCaB. KCaB is half-metallic ferromagnet with a magnetic moment of 1 [Formula: see text] and an energy gap equal to 0.82 eV in the lower spin channel. The [Formula: see text]-type doped exhibits higher Seebeck coefficient, electrical conductivity, thermal conductivity, and figure of merit than the [Formula: see text]-type-doped KCaB at room-temperature 300 K. The half-metallic property is preserved in each of the ends Ca and B on the (111) surface and is lost in the ends K (111) and B and KCa (001) slab surface. The relaxation effect on the electronic spin states decreases the magnetic moment of some atoms on the end surface because the relaxation of the atomic sites is affected and the loss of the nearest neighbors affects exchange–correlation interactions. The surface end with Ca is more stable than the surface end with B on the (111) surface and can maintain the property of half metallic under relatively large stress.

Type 2 Diabetes Overtakes Type 1 in Hispanic Girls

2008 ◽  
Vol 38 (15) ◽  
pp. 18
Author(s):  
SHERRY BOSCHERT
Keyword(s):  
Type 2 Diabetes

Molecular analysis of FVIII gene in severe HA patients of Costa Rica

2010 ◽  
Vol 30 (S 01) ◽  
pp. S150-S152
Author(s):  
G. Jiménez-Cruz ◽  
M. Mendez ◽  
P. Chaverri ◽  
P. Alvarado ◽  
W. Schröder ◽  
...  
Keyword(s):  
Factor Viii ◽  
Coagulation Factor ◽  
Costa Rican ◽  
Factor Viii Gene ◽  
Intron 22 Inversion ◽  
Intron 1 ◽  
Polymerase Chain ◽  
Inversion Analysis

SummaryHaemophilia A (HA) is X-chromosome linked bleeding disorders caused by deficiency of the coagulation factor VIII (FVIII). It is caused by FVIII gene intron 22 inversion (Inv22) in approximately 45% and by intron 1 inversion (Inv1) in 5% of the patients. Both inversions occur as a result of intrachromosomal recombination between homologous regions, in intron 1 or 22 and their extragenic copy located telomeric to the FVIII gene. The aim of this study was to analyze the presence of these mutations in 25 HA Costa Rican families. Patients, methods: We studied 34 HA patients and 110 unrelated obligate members and possible carriers for the presence of Inv22or Inv1. Standard analyses of the factor VIII gene were used incl. Southern blot and long-range polymerase chain reaction for inversion analysis. Results: We found altered Inv22 restriction profiles in 21 patients and 37 carriers. It was found type 1 and type 2 of the inversion of Inv22. During the screening for Inv1 among the HA patient, who were Inv22 negative, we did not found this mutation. Discussion: Our data highlight the importance of the analysis of Inv22 for their association with development of inhibitors in the HA patients and we are continuous searching of Inv1 mutation. This knowledge represents a step for genetic counseling and prevention of the inhibitor development.

Polymorphisms of the Plasminogen Activator Inhibitor- 1 Gene in Type 1 and Type 2 Diabetes, and in Patients with Diabetic Retinopathy

1994 ◽  
Vol 71 (06) ◽  
pp. 731-736 ◽  
Author(s):  
M W Mansfield ◽  
M H Stickland ◽  
A M Carter ◽  
P J Grant
Keyword(s):  
Diabetic Retinopathy ◽  
Plasminogen Activator Inhibitor ◽  
Allelic Frequency ◽  
Repeat Sequence ◽  
Dinucleotide Repeat ◽  
Plasminogen Activator Inhibitor 1 ◽  
The Difference ◽  
Pai 1

SummaryTo identify whether genotype contributes to the difference in PAI-1 levels in type 1 and type 2 diabetic subjects and whether genotype relates to the development of retinopathy, a Hind III restriction fragment length polymorphism and two dinucleotide repeat polymorphisms were studied. In 519 Caucasian diabetic subjects (192 type 1, 327 type 2) and 123 Caucasian control subjects there were no differences in the frequency of the Hind III restriction alleles (type 1 vs type 2 vs control: allele 1 0.397 vs 0.420 vs 0.448; allele 2 0.603 vs 0.580 vs 0.552) nor in the allelic frequency at either dinucleotide repeat sequence. In 86 subjects with no retinopathy at 15 years or more from diagnosis of diabetes and 190 subjects with diabetic retinopathy there was no difference in the frequency of Hind III restriction alleles (retinopathy present vs retinopathy absent: allele 1 0.400 vs 0.467; allele 2 0.600 vs 0.533) nor in the allelic frequencies at either dinucleotide repeat sequence. The results indicate that there is no or minimal influence of the PAI-1 gene on either PAI-1 levels or the development of diabetic retinopathy in patients with diabetes mellitus.

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