Investigation of vacancy formation and phase transformations in uranium by positron annihilation

Autor:	H. Matter, W. Triftshäuser, J. Winter
Rok vydání:	1980
Předmět:	Physics Nuclear and High Energy Physics chemistry.chemical_element Trapping Classification of discontinuities Uranium Lower limit Thermal expansion Nuclear Energy and Engineering chemistry Vacancy defect Phase (matter) General Materials Science Atomic physics Positron annihilation
Zdroj:	Journal of Nuclear Materials. 88:273-278
ISSN:	0022-3115
DOI:	10.1016/0022-3115(80)90283-4
Popis:	Measurements of the positron annihilation coincidence count rate at the peak of the angular correlation curve (CCR) in uranium were performed as a function of temperature between 550 and 1350 K. The α → β and β → γ phase transformations are reflected by discontinuities of the CCR. The low temperature slope of the curve, the change at the α → β transition at 941 K, and the initial slope in the β phase can be very well described by linear thermal expansion. The jump of the CCR at 1048 K is predominantly due to the vacancy trapping effect. Applying the trapping model to the data in the 7 phase, a lower limit of about 1 eV has been obtained for the monovacancy formation energy EF1v. This result leaves only a very small value for the vacancy migration energy EM1v.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::0ea6d564818d9650928ed34d57982bdc https://doi.org/10.1016/0022-3115(80)90283-4 Zobrazit plný text záznamu