A Study of the Mechanism of Sensitized Luminescence of Solids

Schulman, James H.; Ginther, R. J.; Klick, Clifford C.

doi:10.1149/1.2777979

Cited by 31 publications

(20 citation statements)

References 10 publications

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“…Assuming an average value for the ratio of quantum outputs of 1.8 and a concentration of activator equal to 2.6 mole % MnCO3, the range over which energy is transferred, K, is 39 atoms. This is in agreement with experimentally determined values for other systems (4,8,9) as well as the theoretically predicted value (11).…”

Section: Sensitized Luminescencesupporting

confidence: 92%

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Modified Calcium Pyrophosphate Phosphors

Kinney

1955

J. Electrochem. Soc.

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The preparation and optical properties of (Ca,NaD2P2OT:Sb and (Ca,Na~)2P2OT: Sb:Mn phosphors are described. The partial substitution of sodium for calcium has been found to increase markedly the efficiency of the luminescent emission. The enhancement of luminescence as a result of this modification is attributed to compensation of valence : Sb +3 and Na +1 compensating for two Ca +2 in the lattice. The doubly activated phosphor provides an example of "sensitized luminescence." (Ca,Na2)2P2OT:Sb fluoresces in the deep blue. The observed fluorescence of (Ca, Na2)2PeOT: Sb:Mn may vary between blue-white and pink-white depending upon the manganese concentration.

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Section: Sensitized Luminescencesupporting

confidence: 92%

“…The range of transfer of energy from sensitizer to activator may be calculated according to the relationship (4,8,9) Quantum Output Mn…”

Section: Sensitized Luminescencementioning

confidence: 99%

Modified Calcium Pyrophosphate Phosphors

Kinney

1955

J. Electrochem. Soc.

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“…The previous observation (8) that irradiation in the 235 m~ absorption band does not excite the visible Mn ~ § emission in CaSiO~:Pb -t-Mn is explained easily by the fact that Mn crystallizes preferentially in the fl-CaSiO3 lattice (5, 6) and therefore it is necessary to excite the Pb atoms in fl-CaSiO3: Pb, which absorbs at 255 m~, but not at 235 m~.…”

Section: Discussionmentioning

confidence: 96%

Optical Properties of Tin- and Lead-Activated Calcium Metasilicate Phosphors

Mooney

1959

J. Electrochem. Soc.

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The preparation and optical properties of two new tin-activated calcium metasilicate phosphors are described. The more efficient of these is a ~-CaSiO~: Sn phosphor emitting in the visible at about 520 rn~. The optical properties of the tin-activated species are compared to their lead-activated analogues; and from considerations of crystal structure as affected by firing temperature and activator concentration, it is concluded that changes in spectra result from changes in crystal structure and not from the degree of aggregation of the activator ions. It is suggested that the emission spectra correspond to the 8po.~ ~So and the ~p0_~ ~So transitions of the lead-and tin-activator centers.Calcium metasilicate activated by lead and manganese is a well-known phosphor with a visible emission band at 610 m~ and an ultraviolet emission band at about 350 m~ (1-3). A study of the effect ol crystal structure (4) showed that the inversion temperature of B-CaSiO3 (wollastonite) to a-CaSiO~ (pseudowollastonite) is raised with increasing manganese concentration in agreement with results reported by Voos (5), who showed that MnSiO~ (rhodonite), being an isomorph of fl-CaSiO~, forms mixed crystals with wollastonite. A more recent study (6) of the influence of crystal structure on fl-CaSiO~:Pb + Mn showed that at temperatures where both wollastonite and pseudowollastonite are formed, the manganese crystallizes in the wollastonite lattice to the extent that a red shift is produced by the concentration of manganese in the fiCaSiO~, structure. It was shown also that the addition of magnesium oxide to calcium metasilicate increased the inversion temperature of fi-CaSiO~ to a-CaSiO3, whereas the addition of strontium oxide lowered the inversion temperature thus favoring the formation of pseudowollastonite.The calcium silicates activated by lead alone were studied in detail by Studer and Fonda (7). They found several emission bands in the ultraviolet which they attributed to differences in crystal structure as follows: two bands at 300 m~ and 385 m# to a-CaSiO~: Pb, a 345 m~ band to fl-CaSiO~: Pb, and a 334 m~ band to fl-Ca~SiO4: Pb. The corresponding excitation spectra varied widely with several maxima between 200 and 300 m~. In a later study of the mechanism of sensitized luminescence of solids, Schulman and co-workers (8) claimed that the differences in emission were due to differences in the nature of the lead activator center rather than to changes in crystal structure. Specifically, they claimed that the emission bands at 290 and 390 m~ in CaSiO~:Pb were caused by Pb ~+ singlet centers, i.e., Pb "~ § activator ions which had no otherPb ~+ nearest neighbors; whereas the single-band emission at 340 m~ observed at higher lead concentrations was attributed to the occurrence of Pb~+-Pb ~+ doublets or higher aggregates of Pb ~+ ions, i. e., centers which had 2 or more Pb =+ ions in neighboring cation positions.Due to the similarities in electronic configuration between lead and tin and the resulting similarities in chemical behavior, i...

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“…GAMMA-RAY DOSIMETER GLASS Dosimeters, capable of measuring total gamma-ra3' .dosage from very low levels up through the lethal range, are now in volume production for the armed forces. These are made from a potassium, aluminum, phosphorus, silver, barium oxide glass (1,5).…”

Section: Reproducing Photographs In Plate or Window Glassmentioning

confidence: 99%

“…THE announcement of the first practical photosensitive glass (ß) in 1947 has been followed by development of other types of photosensitive glass, new related products, and applications. Some of these have been logical developments from the same research, and others, such as gamma-ray dosimeters developed by Schulman, Weyl et al (1,5), have resulted in answer to the requirements of work with atomic energy. This paper reviews the present status of the previously reported glasses and describes new developments.…”

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confidence: 99%

Recent Developments in Radiation-Sensitive Glasses

Stookey¹

1954

Ind. Eng. Chem.

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A Study of the Mechanism of Sensitized Luminescence of Solids

Cited by 31 publications

References 10 publications

Modified Calcium Pyrophosphate Phosphors

Modified Calcium Pyrophosphate Phosphors

Optical Properties of Tin- and Lead-Activated Calcium Metasilicate Phosphors

Recent Developments in Radiation-Sensitive Glasses

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