Optical spectroscopy of , and single crystals

Abstract

The optical absorption and photoluminescence properties of PrTiNbO 6 , NdTiNbO 6 and ErTiNbO 6 crystals grown by laser-heated pedestal growth (LHPG) have been measured at T = 14 K, 77 K and 300 K. These spectra show very high absorption coefficients for the three rare-earth (RE) ions and strong luminescence signals characteristic of ions at high concentration in distorted symmetry sites. The rare-earth ions in these compounds are shown to occupy single sites only. The strong luminescence output at 300 K makes these crystals potential hosts for diode-pumped laser gain media.

Microwave Dielectric Properties of RE1−xRE′xTiNbO6 [RE = Pr, Nd, Sm; RE′= Gd, Dy, Y] Ceramics

“…The primary requirements of any candidate dielectric resonator (DR) material are (a) high dielectric constant (ε r ) to allow size reduction of the components, (b) small dielectric loss or high-quality factor for selectivity, and (c) stability with temperature (i.e., temperature coefficient of resonant frequency ( f ) should be minimum). [13][14][15] The single crystals of these stoichiometric rare-earth compounds are also used as ideal gain media for miniature solid-state lasers 16,17 because of their exciting optical properties. Several dielectric ceramics have been investigated in attempts to find new materials for practical applications.…”

“…16,21 Compounds with an atomic number of the rare-earth ions in the range of 64 -71 have an orthorhombic euxenite structure, but have a different symmetry Pbcn. They fall in the space group symmetry Pnma.…”

Synthesis, characterization and properties of [RE1−xREx′]TiNbO6 dielectric ceramics

“…Recently RETiNbO 6 (RE: rare earth ion) is reported as a useful ceramic material for dielectric resonator applications [10][11][12]. Single crystals of these groups of materials are recently reported as useful for miniature solid state and diode pumped lasers [13,14] The RETiNbO 6 compounds with atomic number of the rare earth ion in the range of 57-63 are known [13][14][15] to crystallize with orthorhombic aeschynite crystal structure with four formula units per unit cell and space group Pnma. Compounds with atomic number of the rare earth ion in the range of 64-71 have euxenite structure.…”

Pr3+ doped LaTiNbO6 as a single phosphor for white LEDs

“…3. The emissions peaked at 477 nm and 490 nm can be assigned, respectively, to the transitions 3 P 1 → 3 H 4 and 3 P 0 → 3 H 4 [13,14], as indicated in the energy level scheme in the inset of Fig. 3.…”

“…Even parity terms in the crystal field expansion cause splitting of the electronic energy levels, whereas odd parity terms result in the mixings of the opposite-parity wavefunctions to allow strong electric-dipole transitions between the RE 3+ multiplets. Stoichiometric RETiNbO 6 (RE = Nd, Pr and Er) has previously been grown in the single crystal form as the potential gain media in miniature lasers pumped by diodes [12][13][14].…”