Structural and Optical Characterization of Ytterbium Doped Lutetium Double Phosphates.

Abstract

Abstract. Powder samples of the ternary phosphates A 3 Lu(PO 4 ) 2 :Yb 3ϩ (A ϭ Na, Rb) have been synthesised by solid state reactions. The spectroscopic properties of Yb 3ϩ in double phosphate host lattices were investigated using absorption, emission and excitation spectra at 4, 10 and 293 K in the VUV to IR range. The results obtained for both types of phosphates are compared. Together with the fundamental 2 F 5/2 Ǟ 2 F 7/2 emission in the IR range, a broad band emission with two peaks in the UV region Compounds containing Yb 3ϩ ions have potential applications as laser devices because of their simple electronic structure. There is no concentration quenching and no excited state absorption reducing the effective laser crossrelaxation process. The Yb 3ϩ ion exhibits intense and broad absorption bands in the IR region which is suitable for a diode-pumped laser. It was reported that ytterbium-doped lasers have longer emission lifetimes than the Nd 3ϩ -doped materials. All these properties of Yb 3ϩ indicate that the ytterbium-doped materials seem to be more promising than the neodymium-doped systems, already employed in laser materials. The fundamental luminescence of the Yb 3ϩ ion originating from the 2 F 5/2 Ǟ 2 F 7/2 transitions between the manifold of Stark-splitted levels occur in the IR range around 1000 nm.While searching for interesting laser host materials for solid state lasers, alkali rare-earth double phosphates of the M 3 RE(PO 4 ) 2 type were studied by several authors [1Ϫ10]. These compounds have their host absorption edge at a rather short wavelength which makes them suitable as host lattices for various luminescent materials.In addition to the intraconfigurational 4f-4f transitions, a broad emission band (called charge transfer band, CT)

Why so deep research on Yb3+-doped optical inorganic materials?

“…Structural and optical characterization of Yb 3+ -doped lutetium double phosphates has also been analysed [41]. Detailed analysis of the Yb 3+ -doped sodium lutetium double phosphates has been performed to determine the energy levels in these hosts and to compare their optical behaviour with analogous sodium yttrium double phosphates [42]. The emission and excitation spectra have been investigated using synchrotron radiation and the origin of the emission has been analysed proving that the emission occurs from the charge transfer state.…”

Structural and Optical Characterization of Ytterbium Doped Lutetium Double Phosphates

“…The bands in the absorption spectra of Na 3 Lu(PO 4 ) 2 :Yb 3ϩ consist of the main three electronic Stark components of the 2 F 5/2 excited level located at 10252, 10555 and 11008 cm Ϫ1 . The total splitting of 756 cm Ϫ1 for Na 3 Lu(PO 4 ) 2 :Yb 3ϩ is a little smaller than that observed for the analogous yttrium salt (801 cm Ϫ1 ) [10].…”

Spectroscopy and structural characteristic of Yb3+ and Nd3+ ions doped nanostructured Lu2O3 and sol–gel derived silica host materials

“…Because of the large energy difference between its charge transfer state and the highest 4f excited state charge transfer luminescence is in some cases possible. Such a luminescence was reported by Nakazawa [2,3] and later by Van Pieterson et al in different hosts [4], and also by us [5,6], but not in nanostructured Lu 2 O 3 obtained by the solution combustion method. Lu 2 O 3 is a valuable host material for various activators [1,[7][8][9], because of good thermomechanical properties, low phonon energy, structural similarity (cubic structure) to others lanthanide sesquioxides.…”