Abstract
The thermoelastic properties of n- and p-type Bi2Te3 under uniaxial stress are investigated. It is assumed that the weakest bondings between the Te(1)-Te(1) double atomic layers give the largest contribution to ( delta T/ delta p)s. The magnitude of the effect for nonstoichiometric Bi2Te3 clearly depends on the Te(2) defect concentration in the centre of the -(Te(1)=Bi=Te(2)=Bi=Te(1))- fivefold layers, indicating the connection between the total number of valence electrons available and the nearest-neighbours configuration. Tellurium vacancies reduced the amount of ionic bonding within the fivefold layers (Bi-Te(1)), but increase the covalent bonding across the Te(1)-Te(1) double layers.
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