First-Principles Study on Structural and Thermoelectric Properties of Al- and Sb-Doped Mg2Si

Hirayama, Naomi; Iida, Tsutomu; Funashima, Hiroki; Morioka, Shunsuke; Sakamoto, Mariko; Nishio, K.; Kogo, Yasuo; Takanashi, Yoshifumi; Hamada, Nobuyuki

doi:10.1007/s11664-014-3508-4

Cited by 13 publications

(5 citation statements)

References 5 publications

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“…We reported previously that the localized shifting of atomic positions was greatest for the nearest-neighbor atoms of impurity atoms, being about 1 to 5%, according to a structural relaxation calculation (variable-cell relaxation) of the atomic positions inside cells using the Quantum Espresso code. 29) Here we investigated the contribution to the lattice constants. The dotted line in Fig.…”

Section: Disorder In the Crystal: Localized Shifting Of Atomic Positionsmentioning

confidence: 99%

Theoretical analysis of structure and formation energy of impurity-doped Mg₂Si: Comparison of first-principles codes for material properties

Hirayama

Iida

Funashima

et al. 2015

Jpn. J. Appl. Phys.

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We theoretically investigate the impurity doping effects on the structural parameters such as lattice constant, atomic positions, and site preferences of impurity dopants for Al-doped magnesium silicide (Mg 2 Si) crystal using the first-principles calculation methods. We present comparison between several codes: ABCAP, Quantum Espresso, and Machikaneyama2002 (Akai KKR), which are based on the full-potential linearized augmented plane-wave method, the pseudopotential method, and KKR/GGA Green's function method, respectively. As a result, any codes used in the present study exhibit qualitative consistency both in the dependence of the lattice constants on the doping concentration and the energetic preference of the Al atom for the following sites; substitutional Si and Mg sites, and interstitial 4b site; in particular, ABCAP, which is based on the all-electron full-potential method, and Quantum Espresso, which is a code of the pseudopotential method, produce closely-resemble calculation results. We also discuss the effects of local atomic displacement owing to the presence of impurities to the structural parameters of a bulk. Using the analytical method considering the local atomic displacement, moreover, we evaluate the formation energy of Na-and B-doped systems as examples of p-type doping in order to examine the possilbility of realizing p-type Mg 2 Si.

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Section: Disorder In the Crystal: Localized Shifting Of Atomic Positionsmentioning

confidence: 99%

Theoretical analysis of structure and formation energy of impurity-doped Mg₂Si: Comparison of first-principles codes for material properties

Hirayama

Iida

Funashima

et al. 2015

Jpn. J. Appl. Phys.

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“…It is necessary to improve the TE performance of Mg 2 Si for practical use as a TE conversion material. Thus, several theoretical and experimental studies have been reported [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. In addition to Bi, which is one of the most important dopants in this system [30][31][32], previous studies have shown that Sb is also an efficient n-type dopant for improving ZT because doping Mg 2 Si with Sb increases σ and decreases κ l [33][34][35].…”

Section: Improvements In the Te Performance Of Mg 2 Si By Lightly Dop...mentioning

confidence: 96%

Recent Studies on the Environmentally Benign Alkaline-Earth Silicide Mg2Si for Middle-Temperature Thermoelectric Applications

et al. 2022

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Most primary energy sources, such as the fossil fuels of oil, coal, and natural gas, produce waste heat. Recycling of this unused thermal energy is necessary in order to increase the efficiency of usage. Thermoelectric (TE) conversion technologies, by which waste heat is directly converted into electricity, have been extensively studied, and the development of these technologies has continued. TE power-generation has attracted significant attention for use in self-powered wireless sensors, which are important for our increasingly sophisticated information society. For the middle-temperature range (i.e., 600–900 K), with applications such as automobiles, intensive studies of high-performance TE materials have been conducted. In this study, we review our recent experimental and theoretical studies on alkaline-earth silicide Mg2Si TE materials, which consist of nontoxic abundant earth elements. We demonstrate improvements in TE performance brought about by lightly doping Mg2Si with isoelectronic impurities. Furthermore, we examine the electrode formation and material coatings. Finally, we simulate the exhaust heat requirements for the practical application of TE generators.

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“…Magnesium (Mg) alloys are one of the development directions of structural and functional materials in the present and will be in the future due to their good damping capacity, low density, high strength-to-weight ratio, and biodegradability . The intermetallic compound of Mg 2 Si is a promising thermoelectric material because of its high thermoelectric performance. − In addition, Mg 2 Si also has excellent hydrogenation properties, making it one of the candidates for hydrogen storage materials . Due to a narrow band gap of about 0.6 eV, Mg 2 Si can be used as an infrared detector operating in the 1.2–2.0 μm wavelength range .…”

Section: Introductionmentioning

confidence: 99%

Effect of Alloying Elements on the Stacking Fault Energy and Ductility in Mg₂Si Intermetallic Compounds

et al. 2021

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Alloying elements can pronouncedly change the mechanical properties of intermetallic compounds. However, the effect mechanism of this in Mg2Si alloys is not clear yet. In this paper, systematic first-principles calculations were performed to investigate the effect of alloying elements on the ductility of Mg–Si alloys. It was found that some alloying elements such as In, Cu, Pd, etc. could improve the ductility of Mg2Si alloys. Moreover, the interatomic bonding mechanisms were analyzed through the electron localization functional. Simultaneously, the machine-learning method was employed to help identify the most important features associated with the toughening mechanisms. It shows that the ground state atomic volume (V GS) is strongly related to the stacking fault energy (γus) of Mg2Si alloys. Interestingly, the alloying elements with appropriate V GS and higher Allred–Rochow electronegativity (En) would reduce the γus in the Mg–Si–X system and yield a better ductility. This work demonstrates how a fundamental theoretical understanding at the atomic and electronic levels can rationalize the mechanical properties of Mg2Si alloys at a macroscopic scale.

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First-Principles Study on Structural and Thermoelectric Properties of Al- and Sb-Doped Mg2Si

Cited by 13 publications

References 5 publications

Theoretical analysis of structure and formation energy of impurity-doped Mg₂Si: Comparison of first-principles codes for material properties

Theoretical analysis of structure and formation energy of impurity-doped Mg₂Si: Comparison of first-principles codes for material properties

Recent Studies on the Environmentally Benign Alkaline-Earth Silicide Mg2Si for Middle-Temperature Thermoelectric Applications

Effect of Alloying Elements on the Stacking Fault Energy and Ductility in Mg₂Si Intermetallic Compounds

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First-Principles Study on Structural and Thermoelectric Properties of Al- and Sb-Doped Mg2Si

Cited by 13 publications

References 5 publications

Theoretical analysis of structure and formation energy of impurity-doped Mg2Si: Comparison of first-principles codes for material properties

Theoretical analysis of structure and formation energy of impurity-doped Mg2Si: Comparison of first-principles codes for material properties

Recent Studies on the Environmentally Benign Alkaline-Earth Silicide Mg2Si for Middle-Temperature Thermoelectric Applications

Effect of Alloying Elements on the Stacking Fault Energy and Ductility in Mg2Si Intermetallic Compounds

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Theoretical analysis of structure and formation energy of impurity-doped Mg₂Si: Comparison of first-principles codes for material properties

Theoretical analysis of structure and formation energy of impurity-doped Mg₂Si: Comparison of first-principles codes for material properties

Effect of Alloying Elements on the Stacking Fault Energy and Ductility in Mg₂Si Intermetallic Compounds