Speaker
Joao Martins Correia
(UFA, Instituto Tecnológico e Nuclear)
Description
This talk reports on the results from the electron emission channeling on-line run of the ECSLI collaboration, which took place during this year’s Mn beam time in September. We were able to determine the lattice sites of implanted 56Mn (2.6 h) in ZnO, Ge and GaAs, and of 61Co (1.6h) in GaN during the run. We found that Mn in ZnO prefers substitutional Zn sites and Mn in Ge substitutional Ge sites. Mn in GaAs occupies substitutional sites as well, but distinguishing between Ga and As sites will only be possible after careful analysis due to the very similar nuclear charges of these two elements. For the study of Co in GaN we exploited the decay chain 61Mn(4.6 s)->61Fe (6 min)->61Co (1.6 h), i.e. 61Mn was implanted and after a waiting period of 30 min lattice location was done on 61Co. We found that Co occupies substitutional Ga sites in GaN. In addition, by means of using the decay chain 59Mn (0.71 s)->59Fe (45 d), we prepared samples of SrTiO3 and KTaO3 doped with 59Fe, for which the lattice location of Fe will be determined during the following months. Finally we prepared a number of InP samples implanted with 111In (2.5 d) in order to do studies of the emission channeling effect as a function of measurement temperature. Measurements were made at 50 K, 100 K, 150 K, 200 K and room temperature. These experiments are intended as a test of our new sample cooling stage, and 111In in InP has been chosen as a model system since the low Debye temperature of InP results in a strong temperature dependence of the emission channeling effect, and due to the fact that substitutional 111In on In sites is not expected to suffer from any other temperature dependence than the InP lattice vibrations.
Author
Dr
Ulrich Wahl
(Instituto Tecnológico e Nuclear (ITN) Sacavém)
Co-authors
Mr
Carlos Pedro Marques
(Instituto Tecnológico e Nuclear (ITN) Sacavém)
Joao Martins Correia
(UFA, Instituto Tecnológico e Nuclear)
Ms
Ligia Amorim
(Faculdade de Ciências da Universidade do Lisboa)
Mr
Lino Pereira
(Faculdade de Ciências da Universidade do Porto)
Prof.
Manuel Ribeiro da Silva
(Centro de Física Nuclear da Universidade de Lisboa)
Mr
Stefan Decoster
(Instituut voor Kern- en Stralingsfysica (IKS) Leuven)
