Crucibleless crystal growth and Radioluminescence study of calcium tungstate single crystal fiber

Radioluminescence study of calcium tungstate crystalline powders and ceramics

“…RL spectra were registered under excitation by X‐rays (~9 keV) at room temperature and β‐rays from 20 to 400 K. The RL curve of the crystal was detected using a Hamamatsu R928 photomultiplier tube (PMT) and a monochromator (FUNBEC Unicrom 100, FUNBEC, São Paulo, Brazil). The β‐radiation from the 90Sr/90Y source and the PMT were positioned along perpendicular axes, forming an angle of 90° with each other …”

“…Ceramic materials usually show a region with high crystallinity inside the grain and an outer region of the grain that may contain local disorder and a higher density of defects; this region is known as the grain boundary . As is known, tungstate has broad and intense absorption bands due to charge transfer from oxygen to metal in the near‐UV region . The absorption bands and radioluminescent (RL) properties may suffer interference from changes in the crystalline order of the material.…”

“…The literature often presents papers focused on approaches to nanostructured systems, films or crystals about the radioluminescent properties of calcium tungstate . This work presents a study of the peculiarities of optical properties of ceramic and powder of CaWO 4 .…”

Morphology-controlled synthesis of NaGd(WO4)2:Eu3+ microcrystals by hydrothermal process

“…The tungstate and double tungstate families have been long known as functional materials and have been used in some fields because of their luminescence properties corresponding to the electron transitions within the 4f shell, such as CaWO 4 [3][4][5], PbWO 4 [6], CdWO 4 [7], BaWO 4 [8,9], KY(WO 4 ) 2 : Yb 3+ [10], NaLaWO 4 [11], K 1Àx Na x Gd(WO 4 ) 2 [12] and NaGd(WO 4 ) 2 [13]. In recent years, one of important applications of tungstates and double tungstates is to be as host materials for rare earth (RE) ions.…”

Growth and spectroscopic properties of Ti-doped sapphire single-crystal fibers

“…On the other hand, laser heated pedestal growth (LHPG) and micro-pulling-down (l-PD) techniques are used to grow single crystal fibers [17,18]. The LHPG technique is based on the utilization of a CO 2 laser beam as the heating source.…”