Crystal structure of the clathratesK8Ga8S38 and K8Ga8Sn38

Kröner, R.; Peters, Karl; Schnering, H. G. Von; Nesper, Reinhard

doi:10.1524/ncrs.1998.213.14.707

Cited by 35 publications

(62 citation statements)

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“…In addition, as shown in next section, it was found that the effect of different configurations of the substitutional atom on the thermoelectric properties was negligible. Moreover, the lowest energy configuration obtained in the present study is more stable than the one calculated by Imai et al 15) by 0.21 eV/f.u., where the previous experimentally determined occupancy 37,40) was used. On the basis of the above result for the stable configurations of substitutional atoms, the formation energies of X 8 Y 8 Si 38 per chemical formula were calculated and are shown in Fig.…”

Section: Codoping Of Guest and Substitutional Atommentioning

confidence: 99%

Energetic Stability and Thermoelectric Property of Alkali-Metal-Encapsulated Type-I Silicon-Clathrate from First-Principles Calculation

2013

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Possible combinations of alkali metal guest atoms and substitutional group-13 atoms in type-I Si clathrate and their thermoelectric properties were investigated using first-principles calculations. All alkali metals could be encapsulated as the guest element into a Si 46 cage, and either Al or Ga was suitable for a substitutional atom. From the formation energy, possible clathrate compositions were selected as K 8 38 . The thermoelectric properties of these compositions were calculated as functions of temperature and carrier density, using the Boltzmann transport equation and the calculated band energy. The obtained dependences of the Seebeck coefficient and electrical conductivity on the carrier density were discussed from the viewpoint of band structure. The thermoelectric properties were optimized to maximize ZT for each composition by controlling the carrier density. ZT µ 0.75 was predicted as the highest ZT value for hole-doped Cs 8 Ga 8 Si 38 .

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Section: Codoping Of Guest and Substitutional Atommentioning

confidence: 99%

Energetic Stability and Thermoelectric Property of Alkali-Metal-Encapsulated Type-I Silicon-Clathrate from First-Principles Calculation

2013

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“…Thus far only a limited set of type II clathrate compositions have been reported [2,[11][12][13][14][15][16][17][18], including the Si 136 [14] and Ge 136 [16] phases which constitute novel allotropes of elemental silicon and germanium, respectively. One promising route to the preparation of new type II clathrate compositions is via framework substitution, a route that has recently begun to be explored [17,18].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of framework-substituted Cs8Na16Cu5Ge131

Beekman

Kaduk²,

Gryko

et al. 2009

Journal of Alloys and Compounds

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“…[39][40][41][42] For all three elements, the 20-and 28-membered cages are very different in size and obtaining clathrates with cages completely filled by 24 guest atoms requires careful consideration of the structural chemistry. Recent methodological advances have actually provided synthetic techniques to obtain stoichiometric type-II clathrates with one type of guest species such as Na 24 Si 136 , [43] but in the first completely filled Si (Cs 8 Na 16 Si 136 ) and Ge (Cs 8 Na 16 Ge 136 ) clathrates, the key factor was to accommodate two very different-sized guest atoms in the differently sized 20-and 28-membered cages.…”

Section: Resultsmentioning

confidence: 99%