Structural Defects of Some Icosahedral Boron-Rich Solids and Their Correlation with the Electronic Properties

Schmechel, Roland; Werheit, H.

doi:10.1006/jssc.2000.8812

Cited by 52 publications

(46 citation statements)

References 44 publications

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“…According to a study of the bonding nature of B 13 C 2 by Balakrishnarajan et al [28], they suggested that the semiconducting behavior in B 13 C 2 might originate from unavoidable boron/carbon substitutional disorder, leading to the localization of electronic states. This seems to correspond to the statement proposed by Schmechel [29] and Werheit [30] that the electron deficiency in B 13 C 2 can be compensated by defects, e.g., substitutional defects and vacancies, splitting off some valence states into a band gap. However, there are no detailed suggestions or calculations demonstrating how such effects should be realized if present.…”

Section: Introductionsupporting

confidence: 88%

Configurational order-disorder induced metal-nonmetal transition inB13C2studied with first-principles superatom-special quasirandom structure method

et al. 2015

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Due to a large discrepancy between theory and experiment, the electronic character of crystalline boron carbide B 13 C 2 has been a controversial topic in the field of icosahedral boron-rich solids. We demonstrate that this discrepancy is removed when configurational disorder is accurately considered in the theoretical calculations. We find that while the ordered ground state B 13 C 2 is metallic, the configurationally disordered B 13 C 2 , modeled with a superatom-special quasirandom structure method, goes through a metal to nonmetal transition as the degree of disorder is increased with increasing temperature. Specifically, one of the chain-end carbon atoms in the CBC chains substitutes a neighboring equatorial boron atom in a B 12 icosahedron bonded to it, giving rise to a B 11 C e (BBC) unit. The atomic configuration of the substitutionally disordered B 13 C 2 thus tends to be dominated by a mixture between B 12 (CBC) and B 11 C e (BBC). Due to splitting of valence states in B 11 C e (BBC), the electron deficiency in B 12 (CBC) is gradually compensated.

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Section: Introductionsupporting

confidence: 88%

Configurational order-disorder induced metal-nonmetal transition inB13C2studied with first-principles superatom-special quasirandom structure method

et al. 2015

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“…The experimental observations have shown that the α and β-rhombohedral boron crystals are semiconductors [37,38]. Although the recent theoretical calculations [6] of the β-rhombohedral boron contradicts to the experimental results since the ideal unit cell of the β-rhombohedral boron (B 105 ) does not represent the real structure which is (B 106.66 ), the semiconductor character of the α-rhombohedral boron has also been calculated theoretically [39].…”

Section: Electronic Properties Of Dwbntsmentioning

confidence: 96%

Free standing double walled boron nanotubes

Sebetci¹,

Mete²,

Boustani³

2008

Journal of Physics and Chemistry of Solids

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Based on density functional calculations we propose stable structures of free standing double walled boron nanotubes in the form of two single walled boron nanotubes inside one another.Puckering of the boron sheets allows the inner atoms of the outer wall and outer atoms of the inner wall to be matched giving sp-type hybrid σ bonding between the walls. The structural stability, in the case of double walled tubes, increases as the bond interaction between the walls strengthens.All the optimized structures reported in this study are electronically conducting in good agreement with the previously calculated metallic behavior of the experimentally observed single walled boron nanotubes.

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“…Indeed, experimental evidence [15] suggests the true structure is a composition-dependent mixture of structural units based on B 12 and B 11 C 1 icosahedra, and likewise a mixture of C-B-C, C-B-B and B-V-B chains (V=vacancy).…”

Section: Introductionmentioning

confidence: 99%

Prediction of orientational phase transition in boron carbide

Widom

Huhn

2012

Solid State Sciences

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The assessed binary phase diagram of boron-carbon exhibits a single intrinsically disordered alloy phase designated "B 4 C" with rhombohedral symmetry occupying a broad composition range that falls just short of the nominal carbon content of 20%. As this composition range is nearly temperature independent, the phase diagram suggests a violation of the third law of thermodynamics, which typically requires compounds to achieve a definite stoichiometry at low temperatures. By means of first principles total energy calculations we predict the existence of two stoichiometric phases at T=0K: one of composition B 4 C with monoclinic symmetry; the other of composition B 13 C 2 with rhombohedral symmetry. Using statistical mechanics to extend to finite temperatures, we demonstrate that the monoclinic phase reverts to the observed disordered nonstoichiometric rhombohedral phase above T=600K, along with a slight reduction on carbon content.

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Structural Defects of Some Icosahedral Boron-Rich Solids and Their Correlation with the Electronic Properties

Cited by 52 publications

References 44 publications

Configurational order-disorder induced metal-nonmetal transition inB13C2studied with first-principles superatom-special quasirandom structure method

Configurational order-disorder induced metal-nonmetal transition inB13C2studied with first-principles superatom-special quasirandom structure method

Free standing double walled boron nanotubes

Prediction of orientational phase transition in boron carbide

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