On the Energy Transfer in the Thermally Annealed KCl: Pb<sup>2+</sup>, Eu<sup>2+</sup> System

Santiuste, J. E. Muñoz; García‐Solé, J.; Manfredi, M.

doi:10.1002/pssb.2221630119

Cited by 4 publications

(4 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a matter of fact, lifetimes in the range of 0.5-1 x 10 -6 s were measured for fluorine, chlorine, and oxide systems (18,26,27), for the transition under study. Shortening of these lifetimes was attributed to nonradiative transitions or energy transfer processes to some acceptor centers (28). The shortening of the lifetime luminescence in the blue, as results from Fig.…”

Section: Discussionmentioning

confidence: 61%

Spectroscopical Analysis of Laser‐Excited Eu2+ β″‐Alumina Crystals

Bicchi¹,

Meucci²,

Tonelli³

et al. 1991

J. Electrochem. Soc.

View full text Add to dashboard Cite

Optical spectroscopy of Eu 2 § ions in the conduction region of ~"-alumina is carried out following excitation with different wavelengths. The analysis of both the time-resolved spectra and the luminescence lifetimes suggests the occupation of two different manifolds of sites for Eu 2 § ions inside the crystal lattice. The defective nature of the conduction plane of 13"-alumina is reflected by the strongly disordered distribution of the crystal fields.Sodium {3"-alumina is a solid electrolyte with a highly anisotropic structure consisting of spinel-like blocks of AP + and 02-ions alternating with relatively loosely packed layers occupied by Na + and O 2-ions (1). Sodium cations easily diffuse within these loosely packed, nearly empty regions, usually referred to as conduction planes, while they do not migrate across the compact spinel blocks. Therefore the material is a two-dimensional ionic conductor and is essentially an insulator in the third dimension, parallel to the c-axis of the crystal. The characteristics of 13"-alumina are extensively dealt with in Ref.(2). The extraordinary ion transport properties of this material are exploited in the ion exchange processes used to introduce in the conduction regions, besides monovalent cations, a large variety of divalent (3) and trivalent (4, 5) ions.The unique ability of sodium 13"-alumina to exhibit fast ion transport for multivalent cations prompted an immediate interest in the study of the optical properties of its exchanged isomorphs with rare earth and transition metal ions, since they could be used as solid-state laser materials (6). As a matter of fact, laser action, in both pulsed and continuous operations, has already been observed in Nd s+ I3"-alumina crystals (7). More recently, spectroscopic studies of Cu+-doped 13"-alumina have suggested that it is a very promising candidate for solid-state tunable lasers over almost the entire visible spectrum (8). With this aim, Eu 2 § I3"-alumina also could constitute another interesting material, due to the strong broad-band emission resulting from 5d-4f transitions, usually exhibited by the divalent europium ions in aluminum oxides (9).In this paper we report on the spectroscopic properties of the fluorescence of a nearly fully Eu2+-exchanged Na + 13"-alumina crystal we have investigated with the help of different laser excitations. Eu 2 ~ ions are found to occupy a large variety of sites with quite different crystal fields. The results are in general agreement with the model of site occupation of rare earth ions as deduced from x-ray experiments and spectroscopic studies on Eu 3+ and Nd 3+ 13"-aluminas (10, 1I). ExperimentalSodium ~"-alumina crystals are usually grown by a flux evaporation method in which a mixture of Na2CO3, MgO, and A1203 is heated in a Pt crucible in air at 1700-1710~ for 14-21 days (12). The crystals, in form of thin platelets (typical thickness 0.1 ram) with sizes ranging from a few square millimeters to about 1 cm 2, are generally well formed and optically clear. Their composition is given ...

show abstract

Section: Discussionmentioning

confidence: 61%

Spectroscopical Analysis of Laser‐Excited Eu2+ β″‐Alumina Crystals

Bicchi¹,

Meucci²,

Tonelli³

et al. 1991

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…It is better to mention here that the substitution of three Cd 2þ ions by two Bi 3þ ions leaving one Cd 2þ -ion site unoccupied (vacancy) on the cation sublattice in CdI 2 is reminiscent of the so-called Suzuki phase frequently observed in alkali halides doped with divalent cations [14]. In terms of such an ordered phase having a particular stoichiometry, however, it is difficult to give an account for the spectral variation with the BiI 3 concentration.…”

Section: Discussionmentioning

confidence: 98%

Optical Absorption of BiI3 Clusters Embedded in CdI2 Films

Kondo

Kato

Saito

2000

phys. stat. sol. (a)

View full text Add to dashboard Cite

CdI 2 and BiI 3 can be made solid solution by quench deposition over the full range of concentration ratio. On annealing of the solution, two-dimensional small clusters of BiI 3 are produced which are coupled to the lattice of CdI 2 host matrix and show confined-exciton absorption. There is too large a barrier for Bi 3þ ions to aggregate to form larger BiI 3 clusters because the aggregation requires two Bi 3þ ions to migrate in a pair in two dimensions. The present experiment opens up the possibility of a method for achieving designed small BiI 3 clusters embedded in the CdI 2 crystal matrix at high densities, with the clusters directly coupled to the lattice of the host matrix.

show abstract

“…In fact, the host lattice need not necessarily be NaCl: the Suzuki phase may exist also in NaBr (Mn 2+ [50]), KCl (Sm 2+ [57], Pb 2+ [58] and Eu 2+ [56,59]), KBr (Mn 2+ [60] and Eu 2+ [59,61,62]), LiF (Mg 2+ [11,63]) and AgCl (Pb 2+ [64]) and even in oxides (MgO:Mn 4+ [31], [65]- [67], NiO:Mn 4+ [67] and CuO:Pb 4+ [32,68]). Suzuki phases including two types of metal impurity cations have even been studied (NaCl:Pb, Eu 2+ [69] and NaCl:Cd, Pb 2+ [70]). The Suzuki phase has been characterized by many experimental methods like x-ray diffraction [10]- [12], [31,32], [34]- [36], [38,58,65,67], ionic conductivity or thermal current measurements [21,35,37,39,52,54,66], specific heat measurements [47], optical spectroscopy [46,50,53,56,59,60,62,…”

Section: The Suzuki Structurementioning

confidence: 99%

“…Suzuki phases including two types of metal impurity cations have even been studied (NaCl:Pb, Eu 2+ [69] and NaCl:Cd, Pb 2+ [70]). The Suzuki phase has been characterized by many experimental methods like x-ray diffraction [10]- [12], [31,32], [34]- [36], [38,58,65,67], ionic conductivity or thermal current measurements [21,35,37,39,52,54,66], specific heat measurements [47], optical spectroscopy [46,50,53,56,59,60,62,65,67,69,70], Raman spectroscopy [12,40,52,53,55], laser spectroscopy [57], magnetic susceptibility measurements [41,48,65,67], electron paramagnetic resonance [45,46,60,64], neutron scattering [49], photoacoustic measurements …”

Section: The Suzuki Structurementioning

confidence: 99%