scholarly journals DFT Investigation on the Electronic, Magnetic, Mechanical Properties and Strain Effects of the Quaternary Compound Cu2FeSnS4

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 509
Author(s):  
Jing Bai ◽  
Jiaying Ji ◽  
Liyu Hao ◽  
Tie Yang ◽  
Xingwen Tan

The electronic, magnetic and mechanical properties of the quaternary compound Cu2FeSnS4 have been investigated with first principle calculations. Its half-metallicity has been identified with spin polarized band structures and its magnetic origination is caused by the strong spin splitting effect in the d orbitals of Fe atoms. The total magnetic moment of 4 μB is mainly contributed by the Fe atoms and the spatial distribution of the magnetic spin density and charge density difference have also been examined. Moreover, several mechanical properties of Cu2FeSnS4 have been derived and its mechanical stability is also verified. The directional dependent Young’s modulus exhibits relatively small anisotropy yet the shear modulus shows strong directional anisotropy. At last, the tetragonal strain effects have been evaluated and their impact on the electronic and magnetic properties are provided. Results show the total magnetic moment stays almost unchanged while the half-metallicity can only be maintained under relatively small variations for both strains. This study can provide comprehensive information about the various properties of Cu2FeSnS4 compound and serve as a helpful reference for its future applications.

2019 ◽  
Vol 9 (5) ◽  
pp. 883 ◽  
Author(s):  
Wenbin Liu ◽  
Xiaoming Zhang ◽  
Hongying Jia ◽  
Rabah Khenata ◽  
Xuefang Dai ◽  
...  

The electronic, magnetic, and mechanical properties were investigated for ZrRhTiZ (Z = Al, Ga) quaternary Heusler compounds by employing first-principles calculations framed fundamentally within density functional theory (DFT). The obtained electronic structures revealed that both compounds have half-metallic characteristics by showing 100% spin polarization near the Fermi level. The half-metallicity is robust to the tetragonal distortion and uniform strain of the lattice. The total magnetic moment is 2 μB per formula unit and obeys the Slater-Pauling rule, Mt = Zt − 18 (Mt and Zt represent for the total magnetic moment and the number of total valence electrons in per unit cell, respectively). The elastic constants, formation energy, and cohesive energy were also theoretically calculated to help understand the possibility of experimental synthesis and the mechanical properties of these two compounds.


Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 678 ◽  
Author(s):  
Xingwen Tan ◽  
Jiaxue You ◽  
Peng-Fei Liu ◽  
Yanfeng Wang

CoFeMnSi has been both experimentally and theoretically proven as a novel spin-gapless semiconductor and resulted in a new research direction in equiatomic full Heusler compounds. Using the first-principles calculation method, we investigated the electronic, magnetic and mechanical properties of CoFeMnSi material in this study. The obtained lattice constant under the LiMgPdSn-type Heusler structure is 5.611 Å and it is fairly consistent with previous experimental results and theoretical calculations. Furthermore, the achieved total magnetic moment of 4 μB follows the Slater–Pauling rule as Mtotal = Ztotal − 24, where Mtotal is the total magnetic moment per formula unit and Ztotal is the total valence electron number, i.e., 28 for CoFeMnSi material. We have also examined the mechanical properties of CoFeMnSi and computed its elastic constants and various moduli. Results show CoFeMnSi behaves in a ductile fashion and its strong elastic anisotropy is revealed with the help of the 3D-directional-dependent Young’s and shear moduli. Both mechanical and dynamic stabilities of CoFeMnSi are verified. In addition, strain effects on the electronic and magnetic properties of CoFeMnSi have been investigated, including both uniform and tetragonal strains, and we found that the spin-gapless feature is easily destroyed with both strain conditions, yet the total magnetic moment maintains a good stability. Furthermore, the specific behaviors under various temperatures and pressures have been accessed by the thermodynamic properties with a quasi-harmonic Debye model, including bulk modulus, thermal expansion coefficient, Grüneisen constant, heat capacity and Debye temperature. This comprehensive study can offer a very helpful and valuable reference for other relative research works.


SPIN ◽  
2020 ◽  
Vol 10 (04) ◽  
pp. 2050029
Author(s):  
M. Hammou ◽  
F. Bendahma ◽  
M. Mana ◽  
S. Terkhi ◽  
N. Benderdouche ◽  
...  

Research Highlights • Electronic, magnetic, elastic and thermoelectric properties of RbCrC alloy are investigated. • Material is half-metallic, ductile and anisotropic in nature. • The total magnetic moment (3[Formula: see text][Formula: see text]B) obeys the Slater–Pauling rule. • The HM RbCrC compound is identified as potential candidate for spintronic applications. • ZT calculated values of 0.89 and 0.94 make RbCrC a promising thermoelectric material candidate for use in future devices. The aim of this work is to investigate the half-metallicity behavior, elastic, thermodynamic and thermoelectric (TE) properties of the Heusler compound RbCrC using the generalized gradient approximation (GGA-PBE96) and the modified Becke–Johnson (mBJ) approach. The electronic band structures and density of states reveal that RbCrC is a half-metallic ferromagnet (HMF). The calculated total magnetic moment of 3[Formula: see text][Formula: see text]B follows the Slater–Pauling rule ([Formula: see text]). The half-metallicity character can be maintained in the 5.4–7.4 Å lattice constants range and the 0.8–1.2 [Formula: see text]/[Formula: see text] ratio range. Existence of half-metallic ferromagnetism in RbCrC makes it a promising material for practical applications in the spintronic field. Also, the RbCrC exhibits a ductile and anisotropic behavior. The quasi-harmonic Debye model (QHDM) is used to calculate the thermodynamic properties. The BoltzTraP code which is based on semi-classical Boltzmann theory (SCBT) is applied for calculating TE properties. According to the obtained figure of merit values (ZT between 0.89 and 0.94 from 50 K to 800 K), the RbCrC alloy remains a good candidate for thermoelectric applications.


2015 ◽  
Vol 10 (2) ◽  
pp. 2663-2681
Author(s):  
Rizk El- Sayed ◽  
Mustafa Kamal ◽  
Abu-Bakr El-Bediwi ◽  
Qutaiba Rasheed Solaiman

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as melt–spun ribbons  as a function of antimony content .The stability  of these structures has  been  related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition.  The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes. 


2018 ◽  
Vol 69 (5) ◽  
pp. 1272-1275 ◽  
Author(s):  
Camelia Tecu ◽  
Aurora Antoniac ◽  
Gultekin Goller ◽  
Mustafa Guven Gok ◽  
Marius Manole ◽  
...  

Bone reconstruction is a complex process which involves an osteoconductive matrix, osteoinductive signaling, osteogenic cells, vascularization and mechanical stability. Lately, to improve the healing of the bone defects and to accelerate the bone fusion and bone augmentation, bioceramic composite materials have been used as bone substitutes in the field of orthopedics and dentistry, as well as in cosmetic surgery. Of all types of bioceramics, the most used is hydroxyapatite, because of its similar properties to those of the human bone and better mechanical properties compared to b-tricalcium phosphate [1]. Currently, the most used raw materials sources for obtaining the hydroxyapatite are: bovine bone, seashells, corals, oyster shell, eggshells and human teeth. There are two common ways to obtain hydroxyapatite: synthetically and naturally. Generally, for the improvement of the mechanical properties and the structural one, hydroxyapatite is subjected to the sintering process. Considering the disadvantages of hydroxyapatite such as poor biodegradation rate, b-TCP has been developed, which has some disadvantages too, such as brittleness. For this reason, the aim of this study is to look into the effect of adding magnesium oxide on the sintering behavior, the structure and the mechanical properties of the hydroxyapatite-tricalcium phosphate composites.


1988 ◽  
Vol 127 ◽  
Author(s):  
D. Broc ◽  
F. Plas ◽  
J. C. Robinet

ABSTRACTThe safety of vitrified radioactive waste disposal in granite is based on the concept of multiple barriers, which include an engineered clay barrier placed between the waste package and the granite. The mechanical properties of the swelling clays used were studied with a view to practical application for storage facility dimensioning. This involved a macroscopic examination of the clays swelling capacities (for sealing of storage boreholes) and fracture criteria (mechanical stability).


2016 ◽  
Vol 844 ◽  
pp. 153-156 ◽  
Author(s):  
Mateusz Fijalkowski ◽  
Kinga Adach ◽  
Aleš Petráň ◽  
Dora Kroisová

Rice husks (RH) are characterized by a high content of silicon dioxide up to 23 wt. %. Silica in the form of nanoparticles creates surface layers formed in various plant parts which ensure protective properties and mechanical stability. These nanoparticles with a dimension in the range of tens of nanometers, are formed during biochemical processes and photosynthesis. Individual nanoparticles are interconnected between themselves and between layers with organic phase via cellulose fibres. Accompanying ions mainly potassium, calcium, sodium, magnesium and aluminium extremely important for plant growth have also been identified in rice husks. In this research paper we investigated mechanical properties of composite epoxy resin material, which was composed of ChS Epoxy 520 filled with silica obtained from rice husks. Nanoparticles of silicon dioxide with the size in dozen of nanometers were prepared by calcination of raw plant parts. We found that the 0.1 phr of filling (0.01 g of filler + 10 g of epoxy) demonstrated a significant increase of wear resistance and decrease of coefficient of friction. An excellent adhesion between epoxy resin and silica nanoparticles was also observed. The silicon dioxide in epoxy resin plays the role of the hard phase, which transfers part of the load and protects the surface of polymer against wear. The presence of this filler does not change the mechanical properties of the original resin.


2007 ◽  
Vol 550 ◽  
pp. 289-294
Author(s):  
Suk Hoon Kang ◽  
Jae Hyung Cho ◽  
Joon Sub Hwang ◽  
Jong Soo Cho ◽  
Yong Jin Park ◽  
...  

Cold drawn gold wires are widely applied in electronic packaging process to interconnect micro-electronic components. They basically provides a conducting path for electronic signal transfer, and experience thermo-mechanical loads in use. The mechanical stability of drawn gold wires is a matter of practical concern in the reliable functioning of electronic devices. It is known that mechanical properties of materials are deeply related to the microstructure. With appropriate control of deformation and heat processes, the mechanical properties of final products, such as tensile strength and elongation can be improved. Severe plastic deformation by torsion usually contributes to grain refinement and increment of strength. In this study, microstructure variations with torsion strain followed by drawing and heat treatment were investigated. Analyses by focused ion beam (FIB) and electron backscattered diffraction (EBSD) were carried out to characterize the effect of deformation and heat treatment on the drawn gold wires. Pattern quality of EBSD measurements was used as a quantitative measure for plastic deformation.


2015 ◽  
Vol 44 (43) ◽  
pp. 18769-18779 ◽  
Author(s):  
Philippe F. Weck ◽  
Eunja Kim ◽  
Veena Tikare ◽  
John A. Mitchell

The elastic properties and mechanical stability of zirconium alloys and zirconium hydrides have been investigated within the framework of density functional perturbation theory. Results show that the lowest-energy Pn3̄m δ-ZrH1.5 phase is not mechanically stable.


Sign in / Sign up

Export Citation Format

Share Document