Nonlinear Optical Crystal Y_xLa_ySc_z(BO₃)₄ (x + y + z = 4).

Abstract

= 4). -Large single crystals of approximate composition Y0.57La0.72Sc2.71(BO3)4 are prepared from mixtures of Y2O3, La2O3, Sc2O3, B2O3, and Li2O using 3Li2O·2B2O3 as flux (1050°C, 2 d). The compound crystallizes in the trigonal space group R32 with Z = 3. Measurements of the optical properties indicate a wide transparency range extending into the deep UV, a moderate birefringence, and a high second-order susceptibility coefficient. These features make the compound a promising nonlinear optical material for practical applications. -(YE, N.; STONE-SUNDBERG, J. L.; HRUSCHKA, M. A.; AKA, G.; KONG, W.; KESZLER*, D. A.; Chem. Mater. 17 (2005) 10, 2687-2692; Dep. Chem., Oreg. State Univ., Corvallis, OR 97331, USA; Eng.) -W. Pewestorf 30-014

Incongruent Melting LaxYySc4-x-y(BO3)4: LYSB Nonlinear Optical Crystal Grown by the Czochralski Method

“…% ( x > 0.4) one dominant trigonal phase ( R32 ) over 93 wt % is identified, and two residual phases of Sc 2 O 3 and monoclinic phase ( C2/c ), which are always below 5 and 2 wt %, respectively, can be also observed. These results are in good agreement with those published by Ye et al The property of La 1– x Y x Sc 3 (BO 3 ) 4 compounds (with the compositional parameter x > 0.4) to generate 532 nm radiation by SHG process of 1064 nm laser radiation was successfully tested.…”

“…As can be observed, the LYSB crystal is characterized by a large transparency window, having a cutoff wavelength slightly lower than 200 nm (below to the lower limit of our spectrophotometer), making it a promising candidate for different NLO applications in the UV spectral range. The UV cutoff wavelength is similar to the values reported previously for flux-grown LYSB and LGSB crystals. , Compared to our previous results on Czochralski-grown LGSB crystal, LYSB has a lower UV cutoff wavelength (i.e., 230 nm) making it more suitable for UV applications.…”

“…The unit cell parameters were determined to be a = 9.8098(4) Å and c = 7.9802(3) Å. The unit cell volume was calculated to be V = 665.07 Å 3 , which is slightly higher than that of flux-grown LYSB crystal (657.4 Å 3 ), and very close to the unit cell volume of the Y 0.32 La 0.76 Sc 2.92 (BO 3 ) 4 synthesized compound (666.6 Å 3 ) investigated by Ye et al 18 The elemental composition of the LYSB grown crystal was measured by ICP-AES method, and the compositional uniformity along the growth direction was determined by measuring the elemental composition of samples from different zones (shoulder, body, and tail) of the grown crystal. The obtained results are presented in Table 1.…”

“…The unit cell parameters were determined to be a = 9.8098(4) Å and c = 7.9802(3) Å. The unit cell volume was calculated to be V = 665.07 Å 3 , which is slightly higher than that of flux-grown LYSB crystal (657.4 Å 3 ), and very close to the unit cell volume of the Y 0.32 La 0.76 Sc 2.92 (BO 3 ) 4 synthesized compound (666.6 Å 3 ) investigated by Ye et al…”

“…which limit the NLO applications in the UV wavelength range. ,, To avoid the crystal growth issues, the research has been oriented to Sc derivatives binary borates of LnSc 3 (BO 3 ) 4 -type (Ln = lanthanide), − which presents polymorphism, crystallizing in different structural phases as a function of the ionic radii ratio of Ln and Sc ( r Ln / r Sc ). For example, the LaSc 3 (BO 3 ) 4 –LSB crystal has a monoclinic structure (space group C2/c ), and therefore, the second-order nonlinear susceptibility χ (2) is null, while the YSc 3 (BO 3 ) 4 –YSB crystal is isostructural with the mineral huntite (trigonal structure, space group R32 ) allowing second-order nonlinear effects. , Nevertheless, by doping with small ionic radii lanthanides, the structure of LSB can be modified into trigonal structure (space group R32 ) as in the case of flux-grown crystals La 1– x Nd x Sc 3 (BO 3 ) 4 , or La x Y y Sc z (BO 3 ) 4 , La x Lu y Sc z (BO 3 ) 4 , Bi x La y Sc z (BO 3 ) 4 , and La x Gd y Sc z (BO 3 ) 4 with x + y + z = 4. − Even if LSB crystal has an incongruent melting, it has been grown by the Czochralski method for the first time by Ivonina et al in 1991. Later, Durmanov et al have grown LSB crystals doped with diverse rare-earth ions by the Czochralski method, having different structures in the function of the ionic radii ratio of the doping ions (in the lanthanide sites) and the scandium ion.…”