Near-infrared intraconfigurational luminescence spectroscopy of the Mn5+ (3d2) ion in Ca2PO4Cl, Sr5(PO4)3Cl, Ca2VO4Cl and Sr2VO4Cl (J. Lumin. 54 (1992) 1)

Capobianco, J. A.; Cormier, G.; Bettinelli, M.; Moncorgé, R.; Manaa, H.

doi:10.1016/0022-2313(93)90092-2

Cited by 18 publications

(14 citation statements)

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“…This finding deserves special attention, because due to relatively small size of the Mn 5ϩ ion ͑ionic radius 0.33 Å͒, 43 it usually occupies tetrahedral sites, if available, in host crystals such as Ba 3 (VO 4 ) 2 , 44,45 Ba 5 (PO 4 ) 3 Cl, and Ca 2 VO 4 Cl, 46 and Sr 5 (PO 4 ) 3 Cl. 47,48 In YAlO 3 and CaYAlO 4 crystals there are no tetrahedral sites available for Mn 5ϩ ions. Ionic radii for Mn 4ϩ and Al 3ϩ ions are usually very close to each other in both tetrahedral and octahedral coordination: for tetrahedral Mn 4ϩ and Al 3ϩ the ionic radius is 0.39 Å, and for octahedral Mn 4ϩ and Al 3ϩ the ionic radius is 0.53 Å, respectively.…”

Section: Resultsmentioning

confidence: 99%

Low-field microwave response and electron paramagnetic resonance identification of valence states of manganese including octahedral Mn5+ in YAlO3 and CaYAlO4

Рахимов

Jackson

Jones

et al. 2004

Journal of Applied Physics

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Zero-field signal in the electron paramagnetic resonance spectrum of Mn +2 in silicate glassesMicrowave response near zero magnetic field has been observed in YAlO 3 and CaYAlO 4 crystals dilutely doped with Mn in concentration ranging from 0.005 to 0.2 at. %. The response is due to magnetic-field-dependent nonresonant microwave losses, which co-exist with normal electron paramagnetic resonance ͑EPR͒ absorption due to Mn 2ϩ , Mn 4ϩ , and Mn 5ϩ ions in YAlO 3 and CaYAlO 4 . The valence states of manganese have been identified using a dual mode EPR cavity that allowed spectrum recording with polarization of the magnetic vector B 1 of the microwave perpendicular or parallel to the static magnetic field B 0 . The Mn 2ϩ ion, electron spin Sϭ 5 2 , and Mn 4ϩ , Sϭ 3 2 have been identified using normal B 1 ЌB 0 polarization, while Mn 5ϩ , Sϭ1, in unusual octahedral position, has been identified using B 1 ʈ B 0 polarization. The low-field response did not depend on mutual orientation of the vectors B 1 and B 0 and had the opposite phase with respect to the paramagnetic absorption. This shows that Mn-doped YAlO 3 and CaYAlO 4 exhibit magnetically induced microwave absorption, which has a minimum at zero magnetic field and increases with the applied magnetic field. The response in Mn-doped YAlO 3 increases with the introduction of Ca 2ϩ ions. The existence of manganese in different valence states, particularly metastable Mn 5ϩ in octahedral position, and the effect of calcium co-doping suggest the formation of relatively free charge carriers that can migrate in the vicinity of paramagnetic manganese ions. The spin-dependent mechanism of the charge migration is discussed to explain magnetoinduced microwave losses.

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Section: Resultsmentioning

confidence: 99%

Low-field microwave response and electron paramagnetic resonance identification of valence states of manganese including octahedral Mn5+ in YAlO3 and CaYAlO4

Рахимов

Jackson

Jones

et al. 2004

Journal of Applied Physics

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“…In various hosts such as apatites and spodiosites, Mn V experiences strong crystal fields, due to its high-formal charge, and the 1 E level is always the emitting one. In these materials, the Mn V fluorescence lifetime ranges from ϳ300 to 1200 s at ϳ10 K. 40,41 …”

Section: Cr IV :Li 2 Mgsio 4 Single Crystals Optical Characterizationmentioning

confidence: 99%

Spectroscopic characterization of chromium (IV, V, VI) in Cr:Li2MSiO4 (M=Mg,Zn)

Jousseaume

Vivien

Kahn‐Harari

et al. 2003

Journal of Applied Physics

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To understand the exceptionally long fluorescence lifetime of Cr IV in Li 2 MSiO 4 (M ϭMg,Zn), several spectroscopic investigations are performed on Cr:Li 2 MSiO 4 (M ϭMg,Zn) crystals. X-ray absorption near-edge structure investigations attest that chromium is localized in tetrahedral sites and that Cr VI is the major species while Cr IV is the minor one in both compounds. Electron paramagnetic resonance studies confirm the occurrence of Cr V in elongated tetrahedral environment (d x 2 Ϫy 2 ground state͒, corresponding probably to the silicon site, and suggest the presence of several charge compensation schemes. Fluorescence and fluorescence dynamics of Cr IV :Li 2 MSiO 4 are reported. The very long Cr IV excited state lifetime previously observed on powders samples is confirmed for the crystals ͑117 s at room temperature, 305 s at 30 K for Cr:Li 2 MgSiO 4 ) and is explained by combined contributions to the emission from both 1 E level and the lowest component of the 3 T 2 level, in thermal equilibrium. Contrary to the situation found in most Cr IV activated compounds, the 1 E level lies below the 3 T 2 one.

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“…Recent work on near-infrared (NIR) tunable solid state laser materials has focused on the dopant Cr 41 in several host lattices with Cr 41 :Mg 2 SiO 4 emerging as the leading technological system. The success of Cr 41 :Mg 2 SiO 4 as a tunable NIR laser material [1] has stimulated numerous recent studies of the spectroscopic properties of Cr 41 [2][3][4][5][6][7][8][9] and other 3d 2 dopants (Mn 51 , Fe 61 ) [10][11][12][13][14] because of the need for new NIR optical materials. Current work on Cr 41 :Mg 2 SiO 4 continues to focus on tunable NIR laser applications [15], as well as applications in frequency doubled visible [16] and ultrafast lasing [17].…”

Section: Department Of Chemistry Washington State University Pullmamentioning

confidence: 99%

Influence of Low-Symmetry Distortions on the Luminescence ofCr4+-Doped Forsterite

Shen

Bray

2000

Phys. Rev. Lett.

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By using pressure to vary the extent of nontetrahedral distortions of the Cr4+ site in Mg2SiO4, we reveal the important influence of the 3T1 state on the emission properties of the 3T2 state. We find that 3T1-3T2 mixing has a pronounced effect on the line shape and radiative decay rate of emission from the 3T2 state and that the extent of mixing depends critically on the magnitude of nontetrahedral distortions. The results provide an explanation for the wide variation of Cr4+ emission properties in different host lattices at ambient pressure and indicate that the tailoring of asymmetric distortions of luminescent centers represents an effective new strategy for tuning the linewidth of spectral transitions.

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Near-infrared intraconfigurational luminescence spectroscopy of the Mn5+ (3d2) ion in Ca2PO4Cl, Sr5(PO4)3Cl, Ca2VO4Cl and Sr2VO4Cl (J. Lumin. 54 (1992) 1)

Cited by 18 publications

References 0 publications

Low-field microwave response and electron paramagnetic resonance identification of valence states of manganese including octahedral Mn5+ in YAlO3 and CaYAlO4

Low-field microwave response and electron paramagnetic resonance identification of valence states of manganese including octahedral Mn5+ in YAlO3 and CaYAlO4

Spectroscopic characterization of chromium (IV, V, VI) in Cr:Li2MSiO4 (M=Mg,Zn)

Influence of Low-Symmetry Distortions on the Luminescence ofCr4+-Doped Forsterite

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