| Автор | R Chidambaram |
| Автор | M K Sanyal |
| Автор | P M G Nambissan |
| Автор | P Sen |
| Дата выпуска | 1990-12-10 |
| dc.description | A positron annihilation study of the icosahedral Al-Cu-Fe alloy system has been carried out using both Doppler broadening and lifetime measurement techniques. Isochronal annealing studies show that a nearly unchanged two-component lifetime spectrum is obtained up to the highest annealing temperature of 450 degrees C used in the present work, indicating the stability of the structure and the defect state in this quasicrystalline phase up to this annealing temperature. The vacancy defect concentration is about 8 ppm which is higher than that observed in the authors' earlier study on icosahedral Al-Mn-Si, though the vacancy size is lower-approximately a monovacancy size on average in Al-Cu-Fe against a divacancy size in Al-Mn-Si. The existence of such a high concentration of vacancy defects even in quasicrystalline Al-Cu-Fe, which has little phason disorder, should be significant from the point of view of developing a structural model for quasicrystals. It appears that a two-component positron lifetime spectrum indicative of a high concentration of vacancy-type defects is characteristic of the icosahedral quasicrystalline phase. The possibility of a central hole in the icosahedral building block in this phase is ruled out from the authors' positron annihilation experiments. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | A positron annihilation study of vacancy-type defects in Al-Cu-Fe quasicrystals |
| Тип | paper |
| DOI | 10.1088/0953-8984/2/49/018 |
| Electronic ISSN | 1361-648X |
| Print ISSN | 0953-8984 |
| Журнал | Journal of Physics: Condensed Matter |
| Том | 2 |
| Первая страница | 9941 |
| Последняя страница | 9947 |
| Аффилиация | R Chidambaram; Phys. Group, Bhabha Atomic Res. Centre, Bombay, India |
| Аффилиация | M K Sanyal; Phys. Group, Bhabha Atomic Res. Centre, Bombay, India |
| Аффилиация | P M G Nambissan; Phys. Group, Bhabha Atomic Res. Centre, Bombay, India |
| Аффилиация | P Sen; Phys. Group, Bhabha Atomic Res. Centre, Bombay, India |
| Выпуск | 49 |
