УДК 539.216 EFFECT OF DOPING GE-TE ALLOYS WITH CO ON THE STRUCTURAL AND OPTICAL PROPERTIES Iman. <...> Структурные и оптические свойства GeTe и Ge50-x Cox Te50 и CoGe. <...> The X-ray diffraction measurements show that, the prepared samples are in crystalline form, GeTe has rhombohedral structure, otherwise the partial replacement of Ge by Co in the ternary alloys change the GeTe structure from rhombohedral to orthorhombic with additional two phases; orthorhombic CoTe2 Ключевые слова: халькогенид GeTe, кобальт, легирование, рентгеновская дифрактометрия, ИК-спектроскопия. <...> Structural and optical properties of GeTe and Ge50-x CoxTe50 alloys where x = 5, 10 and and monoclinic CoGe phase. <...> The IR absorption measurements shows that, the investigated GeTe and GeCoTe samples have a phonon absorption in the spectral range 1000—800 cm–1 . <...> Keys word: chalcogenide GeTe, transition metal “Co”, doping, structure measurements, IR Absorption. 1. <...> INTRODUCTION Compounds with the skutterudite structure (CoAs3 ) have attracted the attention of thermoelectric research since the early 1990s in its its pursuit for new generation of thermoelectric materials. <...> Due to their structure, containing two large voids in the unit cell, which could be “filled” with a foreign ions acting here as effective phononscattering centres, skutterudites serve as a very typical example of an idial thermoelectric material. <...> N-type CoGe1.5 first time studied as a potential thermoelectric material [1]. <...> Tellurium vacancies or ionized surplus Ge atoms are proTe1.47 © Iman. <...> A. Mahdy, Seredin P. V., Domashevskaya E. P., Yathenko O. B., 2008 composition with compound was for the gether with possibility to influence its thermoelectric properties by proper doping and void filling is therefore of interest of further thermoelectric research. <...> The temperature dependence of the electrical resistivity and the magnitude of the Seebeck coefficient indicate that CoGe1.5 tor as like as CoGe1.5 Te1.5 Te1.5 ВЕСТНИК ВГУ, СЕРИЯ: ФИЗИКА. <...> Two regions corresponding to extrinsic and intrinsic conductivity were identified on the temperature dependence of electrical conductivity. <...> CoGeTe represents a ternary ordered variant of -NiAs2 type structure. <...> Temperature dependence of the electrical conducti vity and Seebeck coefficient at 300K reviled that, CoGeTe sample has a very weak temperature dependence <...>