Eu-Doped BaTiO3 Powder and Film from Sol-Gel Process with Polyvinylpyrrolidone Additive

Abstract

Transparent BaTiO3:Eu3+ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO3:Eu3+ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu3+ doped BaTiO3.

Raman Responses in Mechanically Activated BaTiO3

“…It was also determined that tensile stress was larger in samples with smaller grains and it can be released by annealing to obtain larger BaTiO 3 grains . Furthermore, the shift of Raman band positions in the fine grained powder spectrum could be attributed to internal stress from surface tension in the nanocrystals, as well . Our investigations have shown that the change in position of the A 1 (2TO) mode and Raman peak at 520 cm −1 , with increase in activation time, follows the same trend [Fig.…”

Anharmonic phonon properties in Eu0.5Ba0.5TiO3

“…The parameters of the model have been used for the ES (electrical) and the MS (magnetic) systems: J 1 = 0.8 K, J 2 = −0.5 K, Ω = 5 K , and the bare phonon frequency (i.e. harmonic phonon frequency) ω 0 = 253 cm −1 [8,16], (4) = −2.5 cm −1 , the spin P = 3.5 and the pseudo-spin S = 0.5. These parameters can produce T C = 213 K and T N = 1.9 K. Fig.…”

Structural and Luminescence Properties of Lu2O3:Eu3+ F127 Tri-Block Copolymer Modified Thin Films Prepared by Sol-Gel Method

“…However, it is difficult to achieve thick films without cracking along the ideal thickness in order to satisfy practical applications. A possible alternative is the incorporation of a high boiling point reagent into the sol such as the polyvinylpyrrolidone (PVP), which has been employed in luminescent systems such as Gd 2 O 3 :Eu 3+ [ 22 ], GdTaO 4 :Eu 3+ [ 23 ] and BaTiO 3 :Eu 3+ [ 24 ]. A different alternative is to add Pluronic F127 acid, a PEO 106 PPO 70 PEO 106 (PEO = polyethylene oxide, PPO = polypropylene oxide) tri-block copolymer with an average molecular weight of 13600 g mol −1 , which has also been found to act as a structure-directing agent in TiO 2 [ 25 , 26 , 27 ] in catalytic and solar cells applications.…”