Effect of microstructure on positron-annihilation parameters in
- 1 September 1988
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 38 (7), 5126-5129
- https://doi.org/10.1103/physrevb.38.5126
Abstract
The temperature dependence of positron Doppler line shape has been measured for several samples of (x≤0.1). Two distinct temperature dependences have been observed. In one case the line-shape parameter S increases by ≊0.5% between 15 and 100 K, remains constant between 100 and 230 K, and then decreases by ≊0.25% between 230 and 290 K. In the second case, S remains constant between 20 and 100 K, decreases by ≊1% between 100 and 200 K, and then remains constant up to 290 K. Room-temperature positron-lifetime measurements also reveal distinct differences between samples. An explanation of these differences based on micro- structural differences observed by transmission electron microscopy is suggested.
Keywords
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