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تسجيل مستخدم جديدPositional disorder of Ba in the thermoelectric germanium clathrate Ba6Ge25
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The local structure of Ba6Ge25 has been studied by x-ray diffraction and the atomic pair distribution function technique at 40 K and room temperature. Unambiguous evidence has been found that two out of three types of Ba atoms in Ba6Ge25 move off their positions and become locked in split sites at low temperatures.
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In the ternary system Sr-Cu-Ge, a clathrate type-I phase, Sr8Cu5.3Ge40.7 (a = 1.06311(3), exists close to the Zintl limit in a small temperature interval. Sr8Cu5.3Ge40.7 decomposes eutectoidally on cooling at 730{deg}C into (Ge), SrGe2 and tau1-SrCu2
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