Open AccessStructural relaxation and self-diffusion in covalent amorphous solids: Silicon nitride as a model system
Author(s) -
Harald Schmidt,
Wolfgang Gruber,
Thomas Gutberlet,
M. Ay,
Jochen Stahn,
Udo Geckle,
Michael Bruns
Publication year - 2007
Publication title -
journal of applied physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.699
H-Index - 319
eISSN - 1089-7550
pISSN - 0021-8979
DOI - 10.1063/1.2770821
Subject(s) - amorphous solid , materials science , annealing (glass) , silicon , isothermal process , metastability , crystallization , self diffusion , silicon nitride , amorphous silicon , chemical physics , crystallography , chemistry , thermodynamics , crystalline silicon , physics , organic chemistry , metallurgy , composite material , self service , business , marketing
Neutron reflectometry and isotope multilayers were used to investigate self-diffusion in covalent amorphous solids during isothermal annealing and its correlation to structural relaxation. Amorphous silicon nitride was chosen as a model system. Neutron reflectometry is a superior method to measure very low self-diffusivities, occurring in covalent solids, by applying only short time anneals. This allows one to determine time dependent changes of diffusivity over a broad temperature range before crystallization of the metastable solid occurs. The measured nitrogen diffusivities decrease by more than one order of magnitude during annealing between 950 and 1150 °C, while at the same time also a decrease of the atomic density is observed. We interpret this behavior as a structural relaxation of the amorphous network structure that is governed by annihilation of interstitial-like defects.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom