The Czochralski Growth of (Lu_1−xGd_x)₂SiO₅:Dy Single Crystals: Structural, Optical, and Dielectric Characterization

Abstract

The Czochralski growth of Dy 3þ -doped (Lu 1-x Gd x ) 2 SiO 5 solid solution single crystals with different mixtures of Lu 2 SiO 5 and Gd 2 SiO 5 oxides (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) is reported. It was found that the (Lu 1-x Gd x ) 2 SiO 5 crystals retain structural, physical, and optical properties of Lu 2 SiO 5 even for x = 0.8. Optical investigation of Dy:(Lu 1-x Gd x ) 2 SiO 5 revealed that the structural disorder of the host brings about a strong inhomogeneous broadening of Dy 3þ spectral bands while influencing weakly rates of its radiative and nonradiative transitions. Dielectric characteristics of solid solution crystals are presented and discussed. Finally, (Lu 1-x Gd x ) 2 SiO 5 solid solution crystals seem to be an attractive alternative to a Lu 2 SiO 5 host for the design of novel phosphors, radiation converters, and lasers owing to a significantly lower melting temperature and hence easier and less expensive manufacturing.

Growth, spectral properties, and laser demonstration of Nd:(Lu0.5Gd0.5)2SiO5 crystal

“…Recently O. Sidletskiy et al [25] reported a light output by ∼ 70% with respect to Ce:LSO crystals, energy resolution of 6.9 -7.3% at 662 keV ( 137 Cs), slow decay component of only several percents, and lower afterglow level by choosing an optimal Lu content at 30 -60 at.% with the C2/c symmetry and Ce concentration of no more than 0.6 at.%. Besides Ce doping, the (Lu x Gd 1−x ) 2 SiO 5 crystal has also been investigated with Dy 3+ doping [26] and Er 3+ , Yb 3+ codoping [27]. It presented a substantial broadening of dysprosium absorption and emission lines in (Lu x Gd 1−x ) 2 SiO 5 , confirming a structural disorder produced by the substitution of much large Gd 3+ ions in the ordered lutetium oxyorthosilicate (LSO) C2/c structure [26].…”

“…Besides Ce doping, the (Lu x Gd 1−x ) 2 SiO 5 crystal has also been investigated with Dy 3+ doping [26] and Er 3+ , Yb 3+ codoping [27]. It presented a substantial broadening of dysprosium absorption and emission lines in (Lu x Gd 1−x ) 2 SiO 5 , confirming a structural disorder produced by the substitution of much large Gd 3+ ions in the ordered lutetium oxyorthosilicate (LSO) C2/c structure [26]. L. Han et al [27] have studied the upconversion (UC) and near infrared (NIR) emission properties of Er 3+ , Yb 3+ :LGSO crystal and reported an intense UC emission with standardized efficiencies as high as 0.83×10 −3 (green) and 0.93×10 −3 (red), respectively, and an efficient NIR emission at 1543 nm with σ em = 0.994×10 −20 cm 2 .…”

μ-Raman and infrared reflectance spectroscopy characterization of (Lu1−xGdx)2SiO5 solid solution single crystals doped with Dy3+ or Sm3+

“…Effective laser action at around 1µm has been reported for LSO doped with ytterbium ions [16]. Furthermore, LSO and GSO doped with Dy 3+ and Sm 3+ owing to an intense luminescence in the blue and yellow spectral range can be promising systems for applications as white light emitters [1,17].…”

“…The crystals in whose formulae RE stands for rare earth ions from La to Tb crystallize in P2 1 /c space group, while those in whose formulae RE stands for ions from Dy to Lu crystallize in C2/c space group [1,17]. Many ways of realization of isomorphic lattices with monoclinic space group symmetry open the possibility of obtaining doped oxyorthosilicate crystals by substitution of one rare earth element by another [18].…”

“…Most oxyorthosilicates crystallize congruently, and therefore they may be grown by the Czochralski method in the single crystal form. However, the technological problems with crystals growth process have to be considered and from the technological point of view the problem was to decrease the melting points of (Lu 1-x Gd x ) 2 SiO 5 (LGSO) solid solution crystals doped with rare earth ions [1,17].…”