Absorption, emission and lifetime data on Cu+ in some alkali halides

Luminescence of Cu+and Cu2+Ions in CsBr Crystals

“…The existence of both considered models in Cu-doped alkali-halides has been discussed in works [6,[10][11][12]. In our opinion, both of these models can be realized also in CsBr:Cu and CsBr:CuBr 2 crystals.…”

Decay of fluorescence emission of KI: Cu+

“…Nevertheless, these authors subsequently apologized [5] for an instrumental error in their lifetime measurements at low T. Consequently, Bertolaccini et al repeated the experiment [6] by using a better technique, but restricting the investigation to NaC1, NaBr, KBr and RbBr. They noticed [6] that in some cases the lifetime dependence as a function of T is similar to that observed for the oscillator strength of Cu + in an on-centre configuration (i.e. involving a coth function) and, what is more, suggested the possibility of a change from an on-centre (at low T) to an off-centre configuration (at high T).…”

“…These authors, on the basis of the temperature behaviour of the lifetime as well as of the absorption oscillator strength, tried to determine [4] the change on off-and on-centre configuration of the Cu + in its RES. Nevertheless, these authors subsequently apologized [5] for an instrumental error in their lifetime measurements at low T. Consequently, Bertolaccini et al repeated the experiment [6] by using a better technique, but restricting the investigation to NaC1, NaBr, KBr and RbBr. They noticed [6] that in some cases the lifetime dependence as a function of T is similar to that observed for the oscillator strength of Cu + in an on-centre configuration (i.e.…”

“…In conclusion, we were compelled to repeat the lifetime measurements concerning Cu § in order to verify or test the validity of the models proposed in the literature: in this preliminary work we have restricted our attention to the KI case because this host material was not tested by Pedrini and was not checked by Spinolo in his second paper [6].…”

Analysis of a qualitative criterion for forecasting off-centre displacement of impurity ions in ionic crystals

“…Since we were not able to find OFF [15,16] So, in conclusion, a clean cut criterion has not been achieved for the Cu + impurity even if the expected trend on x values has been obtained: there is a region of uncertainty when we are dealing with sodium halides; nevertheless, we want to recall that the data concerning NaI:Cu have not up to now been confirmed, and that NaBr:Cu is a very shallow off-centre system [17], whereas NaChCu is not a normal on-centre system [17] (i.e. it presents a normal substitutional position but with an anharmonic oscillation extended over the several host lattices around the defect ion).…”