Investigation of SHG in new scandium borate with three cations by the Kurtz-Perry method

This work is dedicated to study the optical properties of scandium borates with the general formula RExPrySc2+z(BO3)4 (x + y + z = 2, RE = Nd, Sm, Tb, Tm, Yb), grown by the TSSG method. The structure, absorption and luminescence of these crystals have been investigated

Reduction of amputations of frostbitten limbs by treatment using microwave rewarming

Drug treatment of limb frostbite injuries is complicated due to the poor delivery of medications to affected tissues. External rewarming of the frostbitten area is risky and does not always result in positive outcomes because the dilatation of superficial vessels with constricted deep vessels can lead to irreversible damage, necrosis, and amputation. One of the techniques to restore perfusion of deep vessels in an affected extremity is rewarming with low-power microwave radiation in a specially designed metal chamber. Below are findings following treatment of 14 volunteers with this technique in 2 Tomsk hospitals during winters of 2018–2021. It is demonstrated that timely, i.e. in the early reactive period, application of microwave radiation and appropriate supportive drug treatment results in positive amputation-free outcomes. The key requirement is prompt thermal insulation of the trauma and no prior exposure to external heat sources

Linear and nonlinear optical properties of trigonal borate crystals K7MIn2-xYbx(B5O10)3 (M = Ca, Sr, Ba; x=0…2) with isolated B5O10 units

Noncentrosymmetric borates K7MIn2−xYbx(B5O10)3 (M = Ca, Sr, Ba; x = 0…2) were synthesized by the solid state reaction and the crystals were successfully grown by the top seeded solution growth method using the K2O-B2O3-MF2 flux. According to Rietveld refinement, the crystal structure belongs to the noncentrosymmetric R32 space group. Also, the octahedrally coordinated In atoms are located at wide ranges ∼8 Å which may be promising for phosphor and laser applications. Samples with ytterbium show a characteristic emission band in the range of 950–1050 nm related to the 2F5/2 → 2F7/2 transition of Yb3+ ions that is commonly used for laser generation. IR, Raman and absorption spectra were obtained for the samples as well. The short cut edge of UV absorption, SHG intensity comparable with KDP and low concentration quenching of luminescence suggest that the K7MIn2−xYbx(B5O10)3 borates are promising self-frequency doubling materials

Synthesis and growth of rare earth borates NaSrR(BO3)2 (R = Ho− Lu, Y, Sc)

NaSrR(BO3)2(R = Ho-Lu, Y, Sc) compounds were obtained for the first time. Their structures exhibit disordered positions of Sr2+and Na+ atoms while RO6polyhedra are connected through the BO3 groups. Large distances between R atoms and high transparency in the range of 250-900 nm make them promising for phosphor applications. A pathway to obtain single crystals was shown by growing NaSrY(BO3)2and NaSrYb-(BO3)2by the top seeded solution growth method with Na2O-B2O3-NaFflux

Synthesis and growth of new rare earth borates KCaR(BO3)2 (R= La, Pr and Nd)

Novel KCaR(BO3)2 (R ¼ La, Pr and Nd) compounds have been obtained by solid-state synthesis. Specifically

SHG in γ-Ga2S3 powder

We report results on comparative study of SHG in powder of promising nonlinear γ-Ga2S3 crystal. Digallium trisulfide powders with particle size from 20 μm to 500 μm were tested in comparison with powders of well-known LBO, BBO, KABO, KDP, and LN crystals under the pumping by 7 ns 1064 Nd:YAG laser. Laser-induced damage threshold of different powder fractions were determined. The γ-Ga2S3 shown high damage threshold and large SHG intensity: 56 times to that in LBO powder, 15 in BBO, 50 in KABO, 67 in KDP, and 3 in LN (for particle size: 20–50 μm), that renders it amongst the most promising crystal for frequency conversion of high-intense nanosecond radiation of near-IR lasers by optical rectification technique

Growth and crystal structure of Li3Ba4Sc3B8O22 borate and its Tb3+ doped green-emitting phosphor

A new lithium barium scandium borate (Li3Ba4Sc3B8O22) was obtained by solid-state synthesis and grown by spontaneous crystallization. Single-crystal X-ra

Study of RBO3-ScBO3 phase diagrams and RSc3(BO3)4 orthoborates (R = La, Pr and Nd)

RBO3 – ScBO3 diagrams (R = La, Pr and Nd) were investigated by the solid state synthesis and DSC methods. In these systems the solid solutions based on RSc3(BO3)4, RBO3 and ScBO3 were identified. The single crystals of RSc3(BO3)4 were grown by spontaneous crystallization method from LiBO2-LiF flux. The borates containing Pr and Nd have typical luminescence in the red/IR range which correlated to Pr3+: 3P0 → 3H6, 1D2 → 3H4 (~ 620 nm), and 3P0 → 2F2, 1D2 → 3H5 (~ 655 nm) and Nd3+ electron transitions 4F3/2 → 4I9/2 (875 nm) and 4F3/2 → 4I11/2 (1055 nm). The luminescence intensity strongly depends on the concentration of the fluorophores. In addition the SHG efficiency (for radiation of Nd:YAG laser, 1064 nm) for grown PrSc3(BO3)4 crystals was found to be 1.85 times higher (deff) than for KDP revealing its high potential for various NLO application