Tunneling and rattling in clathrate crystal
نویسندگان
چکیده
منابع مشابه
Rattling ‘‘guest’’ impurities in Si and Ge clathrate semiconductors
In addition to their ground state, diamond structure, Si, Ge and Sn can form crystalline solids called clathrates. As in the diamond structure, in the clathrates, the Group IV atoms are tetrahedrally coordinated and sp covalently bonded to their neighbors. However, the clathrates contain pentagonal atomic rings and have open-framework lattices containing 20-, 24and 28-atom ‘‘cages’’. There are ...
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Atomic motion of guest atoms inside semiconducting clathrate cages is considered an important source for glasslike thermal behavior. 69Ga and 71Ga nuclear magnetic resonance studies on type I Ba8Ga16Sn30 show a clear low-temperature relaxation peak attributed to the influence of Ba rattling dynamics on the framework-atom resonance, with a quadrupolar relaxation mechanism as the leading contribu...
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We have studied the vibrational properties of some of the compounds based on the Type II silicon, germanium, and tin-based clathrate materials using LDA electronic structure methods. The lattices in these framework materials have open cages which can contain weakly bound guest impurities, and these guests produce local (“rattling”) vibrational modes. Such modes may scatter the extended, heat ca...
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Interband quantum tunneling of electrons in semiconductors is of intense recent interest as the underlying transport mechanism in tunneling field-effect transistors. Such transistors can potentially perform electronic switching with lower energy than their conventional counterparts. The recent emergence of two-dimensional (2D) semiconducting crystals provides an attractive material platform for...
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The high temperature form of melanophlogite, 46 Si02. 6M14 .2M12(M12=CH4, N2; M14=C02, N2), is cubic with space group Pm3n and a = 13.436(3) A at 200°C. The mineral is isostructural with the cubic gas hydrates of type I. Structure refinement with 667 independent reflections led to a weighted Rw = 0.040. Corner-sharing [Si04] tetrahedra form a 3dimensional framework which contains two types of c...
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ژورنال
عنوان ژورنال: Physical Review B
سال: 2004
ISSN: 1098-0121,1550-235X
DOI: 10.1103/physrevb.70.184126