Photoluminescence properties of BaMoO4 amorphous thin films

Evolution of photoluminescence as a function of the structural order or disorder in CaMoO4 nanopowders

“…The average crystallite diameter ͑D crys ͒ was determined by XRD, based on the ͑112͒ diffraction peak of the CaMoO 4 phase ͑2 at around 28.8°͒, according to Scherrer's equation. [21][22][23] The microstructure and surface morphology of the CMO annealed between 400-700°C were observed by HR-SEM, using a field emission ͑Supra 35 Gemini-Zeiss microscope͒.…”

“…[15][16][17][18] Our group recently demonstrated that the green PL component increases along with the structural order, and that when the structure is not completely ordered it displays intense visible PL at room temperature. [19][20][21] Considering that the CPM is an efficient soft chemical method to prepare complex oxide materials and that there are controversial interpretations of the PL spectra of molybdate, this work reports on the preparation of ordered and disordered CaMoO 4 nanopowders by CPM and on their characterization. Various complementary characterization techniques were used, including x-ray diffraction ͑XRD͒, optical reflectance spectroscopy, Fourier transform infrared ͑FTIR͒ spectroscopy, and PL spectroscopy to obtain a clearer picture of the physics underlying the luminescence behavior of ordered and disordered CaMoO 4 scheelite structures.…”

Synthesis of Ba1-xCaxTiO3 by Complex Polymerization Method (CPM)

“…By increasing the heat treatment temperature, the crystalline structure seems to be more ordered and the band attributed to the Ti-O bonds, which are more defined. Also, the band at 2350 cm -1 refers to the adsorbed CO2 from atmosphere [8,9]. Such features are in good agreement with XRD and Raman Spectroscopy data and also indicate that CPM is effective in the synthesis of BCT powders.…”

“…This is related to the pH value of the BCT and Ti-CA solutions that are close to 8.5 and 1.5, respectively. Higher pH values (8)(9) promote the deprotonation of the CA, in which the carbons of the acid groups are strongly linked with oxygen and come back more unprotected, the outcome is that more energy is necessary to make these carbon resonates and resonance signals to be shifted to larger ppm values (unshielded) compared to the systems with lower pH values [33]. The -tCOOH carbon group exhibits signals at around 180.9 and 180 ppm for Ba-C5" and Ti-C5", respectively [4,33].…”

“…The CPM achieves molecular mixing of the starting materials and has been successfully used to synthesize several compounds, including BaTiO3, Pb(Zr,Ti)O3 and BaMoO4 [6][7][8][9][10]. The barium titanate (BaTiO3) perovskite, that is one ferroelectrics material, have been extensively studied due several possible applications such as electronic and optical devices [11][12][13][14][15].…”