Spectroscopic properties of Y₃TaO₇powders activated with Eu, Er and co-activated with Yb

Abstract

Abstract.A new synthesis method of Y 3 TaO 7 is reported. Pure phase powders were prepared by modified Pechini technique. Precursors obtained through that route were heated at the temperature about 1000ºC with or without use of Li 2 SO 4 flux. That implicates in different morphology of specimens and also their spectroscopic properties. Eu ions were used as a spectroscopic probe to prove inhomogeneous broadening of excitation and emission spectra. Samples with Er and Yb doping are also presented. Photoluminescence and up-conversion emissions, under 378 nm and 980 nm excitation respectively, strongly depend on the method of powders synthesis.

Theoretical and experimental investigations of mechanical properties for polymorphous YTaO4ceramics

“…The results reveal that the heat transfer of RETa 3 O 9 ceramics deviate from Umklapp scattering process, and the thermal conductivity increases with temperature increasing, which is pertinent to vacancy of RE sites. For cubic Y 3 TaO 7 (space group: ), it is a very interesting host lattice for spectroscopically active ions due to oxygen vacancy derived from the random occupation of the metal ions (Y 3+ and Ta 5+ ) at the same sites of lattice …”

“…For cubic Y 3 TaO 7 (space group: Fm − 3 m), it is a very interesting host lattice for spectroscopically active ions due to oxygen vacancy derived from the random occupation of the metal ions (Y 3+ and Ta 5+ ) at the same sites of lattice. 10 The YTaO 4 compound located at equal molar-composition site of Y 2 O 3 -Ta 2 O 5 binary phase diagram are also appealing as luminescent materials. 1,2,4,[11][12][13] Due to the ferroelastic transformation and low thermal conductivity; however, YTaO 4 shows great potentials in the application of structural materials…”

Phase-sensitive radioluminescence and photoluminescence features in Tm3+-doped yttrium tantalates for cyan and white light generation

“…By using extended X-ray absorption fine structure, Tanaka et al 39 were the first to investigate the cubic Y 3 TaO 7 crystalline structure, to find out that this system crystallizes in a defective fluorite cubic structure. The most recent literature 23,[40][41][42][43] describes this cubic phase as an aniondeficient fluorite-related type structure. The Y 3 TaO 7 system belongs to the space group Fm3 ˉm and has unit cell parameters equal to a = 5.2553(3) Å.…”

“…The Y 3 TaO 7 system belongs to the space group Fm3 ˉm and has unit cell parameters equal to a = 5.2553(3) Å. 39,41 In the fluorite unit cell (M 4 O 8 ), the four M 4+ ions are randomly replaced with three Y 3+ and one Ta 5+ ions, 44,45 and one oxygen vacancy arises per fluorite cell as a result of the charge balance. Consequently, a defective fluorite Y 3 TaO 7 structure is obtained.…”

“…Consequently, a defective fluorite Y 3 TaO 7 structure is obtained. The O-vacancy location varies from site to site, 41 but it is mainly located near Y 3+ . 39,40 In this sense, the Y atom is expected to coordinate with only seven oxygen atoms, while the Ta atom is surrounded by eight oxygen atoms.…”