Preparation and optical properties of samaria‐doped yttria‐stabilized zirconia single crystals

Abstract

Single crystals of yttria‐stabilized zirconia (YSZ) doped with various concentrations of Sm2O3 were synthesized by the optical floating zone method, and their structure and spectroscopic properties characterized using powder X‐ray diffraction (XRD), optical absorption, and luminescence measurements. XRD showed that the cubic phase of ZrO2 was stabilized by addition of Y2O3 and a series of absorption peaks characteristic of Sm3+ was detected by UV‐visible absorption spectroscopy. Three phenomenological J‐O oscillator strength parameters Ωt (t = 2, 4, 6) were calculated to evaluate the local structure and bonding in the vicinity of the Sm3+ for the 0.75 mol% Sm2O3: YSZ sample. These were in order of Ω2 < Ω4 < Ω6 with values of Ω2 = 5.46 × 10−20 cm2, Ω4 = 10.70 × 10−20 cm2, and Ω6 = 12.67 × 10−20 cm2, and indicate a relatively high symmetry and low covalent character for the Sm‐O bond at the Sm3+ sites in the YSZ matrix. Photoluminescence spectra recorded under an excitation of 404 nm showed four emission bands centered at 571 nm, 621 nm, 652 nm, and 716 nm corresponding to the transitions 4G5/2→6Hj (j = 5/2, 7/2, 9/2, 11/2). The transition probability, lifetime, and branching ratio obtained from the emission spectrum of the 0.75 mol% Sm2O3: YSZ crystal showed that YSZ is a potential host for Sm3+ to achieve a reddish‐orange laser output, and the Sm3+‐modified YSZ crystals have a possible use in reddish‐orange laser and lighting devices.

Up-conversion luminescence and Judd–Ofelt analysis of Nd2O3-doped yttria stabilized zirconia single crystals

“…It is accepted that the values of Ω 4 and Ω 6 reflect the stiffness of the single crystals, and χ = Ω 4 / Ω 6 represents a quality factor that is important for characterizing the spectral properties of the (ZrO 2 ) 92 (Y 2 O 3 ) 8- x (Nd 2 O 3 ) x single crystals. 27 In this study, the value of 1.87 for χ is greater than that for Nd 3+ in most other matrices (Table 3), and indicates that (ZrO 2 ) 92 (Y 2 O 3 ) 8 is a potentially valuable matrix material for up-conversion luminescence and near-infrared lasers.…”

“…In this study Ω 4 > Ω 2 > Ω 6 . It is accepted that the 27 In this study, the value of 1.87 for χ is greater than that for Nd 3+ in most other matrices (Table 3), and indicates that (ZrO 2 ) 92 (Y 2 O 3 ) 8 is a potentially valuable matrix material for up-conversion luminescence and near-infrared lasers.…”

“…37 The three emission peaks corresponding to the transitions 4 In most previous studies of rare earth doped YSZ, variation of the number of oxygen vacancies with rare earth doping in YSZ samples where the Y : Zr ratio was kept constant will have induced additional structural distortions from an increased number of oxygen vacancies at high rare earth levels. 27,38 This problem of variation in the number of oxygen vacancies with Nd 3+ content was excluded from the present work by holding the Zr content constant (see Table 1), and the asymmetry at the Nd 3+ site is probably related to local distortions in the (ZrO 2 ) 92 (Y 2 O 3 ) 8−x (Nd 2 O 3 ) x crystal structure caused by the differences in size of the Nd 3+ and Y 3+ ions. It is assumed that the Nd 3+ replaces some of the Y 3+ in the crystal structure because of charge and size similarities, and evidence from section 3.2 shows that the positions of the absorption peaks are independent of Nd 3+ concentration, and thus Nd 3+ substitution does not have a significant effect on the crystal structure.…”

“…8 mol% Y 2 O 3 ), and Y 2 O 3 stabilized ZrO 2 (YSZ) single crystals can function as a high quality matrix for luminescence processes in rare earth ions. [25][26][27] Although the spectroscopic behavior of Nd 3+ in zirconia ceramics has been investigated, there are currently no reports of the optical properties of (ZrO 2 ) 92 (Y 2 -O 3 ) 8−x (Nd 2 O 3 ) x cubic phase single crystals where there should be negligible influence from ions associated with the surface. 28 In the present work, (ZrO 2 ) 92 (Y 2 O 3 ) 8−x (Nd 2 O 3 ) x single crystals containing 8 mol% of a combination of Y 2 O 3 and Nd 2 O 3 were grown from ceramic rods using the optical floating zone method, and their structures were characterized by XRD.…”

“…8 mol% Y 2 O 3 ), and Y 2 O 3 stabilized ZrO 2 (YSZ) single crystals can function as a high quality matrix for luminescence processes in rare earth ions. 25–27 Although the spectroscopic behavior of Nd 3+ in zirconia ceramics has been investigated, there are currently no reports of the optical properties of (ZrO 2 ) 92 (Y 2 O 3 ) 8− x (Nd 2 O 3 ) x cubic phase single crystals where there should be negligible influence from ions associated with the surface. 28…”