Laser heated pedestal growth and optical characterization of CaTa2O6 single crystal fiber

A quantitative analysis of the laser sintering of bismuth titanate ceramics

“…In the last years, laser technology has been employed in a great variety of processes, as drilling, cutting and soldering [5], directional solidification applied to the growth of single-crystal fibers [6,7], surface crystallization and texturing of glasses [8], sintering of coatings and ceramic bulks [9,10]. As laser processing is able to produce peculiar microstructure and in some cases to improve physical properties [10,11], the understanding of its kinetic is a goal for many researchers.…”

Spectroscopic features of erbium-doped CaM2O6 (M=Nb, Ta) single crystal fibers grown by the laser-heated pedestal growth technique

“…Similar XRD and Raman results have been obtained for lead iron tantalates [19], with cubic perovskite structure, for which the spectral broadening was attributed to nanoscale disorders, that cannot be proven by XRD. The maximum phonon energy of CT (850 cm À1 ) is comparable to that of the well-known YAG crystal (840 cm À1 ) [20], and the infrared cutoff is at 6.2 mm [7]. Fig.…”

“…From refinement of these patterns, using the Rietveld method [17], it was possible to confirm the sole formation of orthorhombic CaNb 2 O 6 -space group Pbcn, and cubic CaTa 2 O 6 -space group Pm3, crystalline phases [15,17]. The structural parameters obtained from the refinements are slightly smaller than those previously published for Nd 3+ -doped CN and CT fibers [6][7][8][9], due to smaller ionic radius of Er 3+ . In the case of polymorphic CaTa 2 O 6 , formation of stable cubic phase is due to the high cooling rate associated with the LHPG technique.…”

“…Recently, we have grown and characterized undoped and Nd 3+ -doped CaM 2 O 6 (M ¼ Nb, Ta) single crystal fibers, with excellent optical quality [6][7][8][9], by the versatile and economically advantageous laser-heated pedestal growth (LHPG) technique [10][11][12][13]. Despite its interesting optical and spectroscopic characteristics, CaTa 2 O 6 (CT) has mostly been studied as a dielectric ceramic, for microwave resonators [14], and no work has been reported in crystals.…”

Growth and structural characterization of M-type GdTaO4 single crystal fiber

“…The milling times were of 6, 12 and 24 h. After the powders were dried at 120 1C and the particle size was measured in a Micromeritics SediGraph 5100. Pedestals, cylindrical in shape (1.2 mm in diameter), were obtained by a cold extrusion process as described in previous works [7,8]. The LHPG system used is also described elsewhere [9].…”