Физика Низких Температур: Том 27, Выпуск 9-10 (Сентябрь 2001), c. 1148-1152    ( к оглавлению , назад )

A vitrifying structure transition in the Dy/Mo(112) adsorption system

A. Fedorus, V. Koval , and A. Naumovets

Institute of Physics, National Academy of Sciences of Ukraine, 46 Nauki Ave., Kiev, 03028, Ukraine
E-mail: fedorus@iop.kiev.ua

H. Pfnür

Institut für Festkörperphysik, Universität Hannover, Appelstrabe 2, D-30167 Hannover, Germany
E-mail: pfnuer@fkp.uni-hannover.de

Received April 25, 2001

Аннотация

Annealing-driven irreversible structural transitions are studied by low energy electron diffraction in submonolayer Dy films adsorbed on the Mo(112) surface. In a wide coverage range q > 0.07, Dy overlayers deposited at low temperatures (T 100 K) are ordered and keep their structure upon annealing up to 350-600 K. Near q = 0.68, the overlayers are stable to high-temperature annealing (Ta = 1000 K) as well, whereas the denser films are metastable and transform to more stable ordered structures. An unusual annealing effect is found for q < 0.58: the initially ordered metastable phases are replaced by phases having no extended order, which are assumed to be two-dimensional glasses.

PACS:
64.70.Pf - Glass transitions
64.60.My - Metastable phases