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SUMMARY:Lattice location of the transition metals Co and Ni in Si
DTSTART;VALUE=DATE-TIME:20111207T132000Z
DTEND;VALUE=DATE-TIME:20111207T134000Z
DTSTAMP;VALUE=DATE-TIME:20130526T045330Z
UID:indico-contribution-33@cern.ch
DESCRIPTION:Speakers: Mr. SILVA\, Daniel (Universidade do Porto)\nWe have 
 studied the lattice location of the transition metals 61Co (1.6 h) and 65N
 i (2.5 h) in Si single crystals of various doping types by means of on-lin
 e Emission Channeling using Short-Lived Isotopes (IS453 EC-SLI). 65Ni was 
 directly obtained by means of Ni RILIS ionization\, while for the 61Co exp
 eriments we implanted the short-lived precursor isotope 61Mn(4.6 s) which 
 decays via 61Fe (6 min) to 61Co\, during the Mn RILIS run. In this case on
 ly measurements after a waiting period of 30 min were considered.\nThe sam
 ples were low-doped n-Si (7.3-12 Ohm cm\, in the following named i-Si)\, a
 s well as highly p+ (0.0053 Ohm cm) and n+ (0.0030 Ohm cm) doped Si.\nWhil
 e full quantitative analysis of the measured EC-SLI patterns by means of f
 itting to the results of manybeam simulations of emitter atoms on various 
 lattice sites has not yet been performed\, a qualitative inspection gave t
 he following preliminary results.\n\nDirectly after room temperature impla
 ntation\, the major lattice sites occupied by 61Co and 65Ni were substitut
 ional or near-substitutional sites in all doping types studied.\nHowever\,
  after annealing at 500°C 65Ni changed to tetrahedral interstitial (T) si
 tes in i-Si and p+-Si\, while the majority of 65Ni in n+-Si was found on b
 ond-centered (BC) interstitial sites after the same annealing temperature.
 \nSite changes to interstitial T sites were also observed for 61Co in i-Si
  and p+-Si\, while the case of 61Co in n+-Si is still waiting to be measur
 ed at next year's Mn beam time. \n\nThe behaviour of Co and Ni in Si shows
  hence some similarities to Fe in i-Si\, where site changes from near-S to
  T sites were already observed in previous \nexperiments. However\, there 
 are also clear differences. While the site changes S->T in the case of Ni 
 and Co occurred already after annealing at 475-500°C\, in the case of Fe 
 in i-Si around 600°C was required in order to promote the corresponding e
 ffect. \nAlso\, while Fe showed considerable resistance against high-tempe
 rature annealing\, which went along with the occupation of ideal substitut
 ional sites after 900°C annealing\, Co and Ni started to show partial out
 -diffusion from the samples already for annealing temperatures in the 600-
 850°C range.\n\nhttp://indico.cern.ch/contributionDisplay.py?contribId=33
 &sessionId=9&confId=153820
LOCATION:CERN Council Chamber
URL:http://indico.cern.ch/contributionDisplay.py?contribId=33&sessionId=9&
 confId=153820
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