ANNUAL REPORT - MTA SzFKI

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E-Mail: Kárpát Ferencz optilab@t-online.hu Contract OPTILAB-SZFKI No. 1653/2007 Grants and international cooperations NKFP3A/0005/2002 Nanobiotechnology: Elaborate a method to build nanotechnological devices for use in biology (Coordinator: P. Ormos, Szeged, participant: K. Ferencz, 2002-2007) NKFP3A/071/2004 Nanotechnological material modifications and their metrology (Coordinator: J. Gyulai, <strong>MTA</strong> MFA, participant: K. Ferencz, 2004- 2007) NKFP3A/079/2004 On-site analysis of natural waters, geological media by micro- and nano-sensation methods („Aquanal”) (Coordinator: I. Bársony, <strong>MTA</strong> MFA, participant: K. Ferencz, 2004-2007) Publications See J.32. 74
R. GROWTH AND CHARACTERIZATION OF OPTICAL CRYSTALS I. Földvári, L. Bencs, E. Beregi, G. Dravecz # , V. Horváth, Á. Péter, K. Polgár, Zs. Szaller Growth and study of nonlinear yttrium-aluminium-borate (YAB) crystals. — Optical hyperfine structures (OHS) were detected in Ho-doped YAB single crystals at 9K by high resolution (0.01 cm -1 ) Fourier Transform (FT) spectroscopy. This was a rare co-incidence of high optical quality of the crystals, the extreme resolution of the spectrometer, the single site, tension free incorporation of the dopant, the proper symmetry of the crystal field around the Ho 3+ ions (trigonal prismatic, D 3 Yb-sites), and the 100% natural abundance of the 165 Ho isotope (I=7/2 magnetic moment). Only three other optical crystals are known in the literature (LiYF 4 , CaF 2 and CsCdBr 3 ) where Ho 3+ related OHS were experimentally demonstrated, and those observations were restricted to the 5 I 8 → 5 I 7 , 5 I 8 → 5 I 6 , and 5 I 8 → 5 F 5 transitions. In YAB:Ho OHS was identified in transitions from the ground state 5 I 8 to the 5 I 7 , 5 I 6 , 5 I 5 , 5 F 5 , 5 S 2 , 5 F 4 , 5 F 3 , and 3 K 8 , manifolds. According to the theoretical predictions the number of the split OHS components depended on the degeneracy of the initial and final state of the transitions. Also, the separation of the OHS components was in accordance with the calculated values (0.1-0.2 cm -1 ). The crystal field calculations were in good agreements with the experimental energy levels of all the manifolds in the investigated 4000-23000 cm -1 range, including their Stark components. Growth and study of lithium- and potassium/lithium- niobate single crystals with different compositions and doping. — The room temperature stability region of the tetragonal tungsten bronze-type potassium lithium niobate (K 3 Li 2 Nb 5 O 15, KLN) has been determined by X-ray phase analysis on ceramic samples synthesized by solid state reaction in the composition range of [K 2 O] = 28-33 mol%, [Li 2 O] = 12.5-20.5 mol% and [Nb 2 O 5 ] = 50.5-55.5 mol%. Lattice parameters and temperature dependence of the dielectric constants were measured on single phase samples. The axial a/c ratio of the cell parameters, the density and the Curie temperature of the ferroelectric samples have been found predominantly characteristic for the Nb 2 O 5 content, varying progressively between 3.11-3.14, 4.431-4.596 g/cm 3 and 492-460 o C, respectively. The results are discussed from the points of view of defect chemistry and phase stability. The concentration of intrinsic defects formed primarily by antisite Nb atoms at Li sites has been estimated on the basis of “alkali cation vacancy formation model”. A simple and accurate (~0.02 mol%) spectroscopic method was developed to determine the LiNbO 3 crystal composition close to the stoichiometric region based on the evaluation of the vibrational spectrum of hydroxyl ions which always present in air-grown crystals. It was shown earlier that the intensity ratio of the two infrared band components peaking at about 3480 and 3465 cm -1 (R = I 3480 / I 3465 ) changed linearly with Li 2 O content in the 49.7 – 50.0 mol% range. It was discovered that R depends also on the age of the crystal. However, a simple thermal treatment at about 1000 o C was found suitable to return the crystal to its as-grown state. Thus the spectroscopic test can be applied for LiNbO 3 crystals of unknown thermal history. The role of Mg, Y and Mg+Y co-doping in the formation of periodically poled domain (PPD) structure of the congruent LiNbO 3 single crystals has been investigated. Crystal were grown by the off-centered Czochralski method, both with X and 148 o Y pulling directions. The developed domain structures were examined on chemically etched slices # Ph.D. student 75
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ANNUAL REPORT 2007 RESEARCH INSTITU
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Dear Reader, It is my pleasure to h
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Key figures Permanent staff of the
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A. STRONGLY CORRELATED SYSTEMS J. S
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presented detailed study should hel
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B. COMPLEX SYSTEMS F. Iglói, R. Ju
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B.3. B.4. B.5. B.6. B.7. B.8. B.9.
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the α2 reconstruction increases on
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C.2. C.3. Kádas K, Vitos L, Johans
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C.27. Ropo * M, Kokko * K, Punkkine
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I 25 4 3 Fig. 2. Average intensity
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See also H.6. and nanostructured Pd
Page 26 and 27: Ab initio structure solution. — I
Page 28 and 29: ESA PECS 98021 Phase field modeling
Page 30 and 31: Conference proceedings E.17. Oszlá
Page 32 and 33: Fig. 1. ns-EC to s-EC transition in
Page 34 and 35: Publications Articles F.1. F.2. Bö
Page 36 and 37: G. ELECTRON CRYSTALS G. Kriza, P. M
Page 38 and 39: H. METAL PHYSICS K. Tompa, I. Bakon
Page 40 and 41: thickness can be elucidated by deco
Page 42 and 43: I. METALLURGY AND MAGNETISM L.K. Va
Page 44 and 45: temperature profile increases the s
Page 46 and 47: I.13 Kane * SN, Khinchi * SS, Gercs
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Page 52 and 53: Macromolecular Compounds (Visokomol
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Page 56 and 57: László Temleitner temla@szfki.hu
Page 58 and 59: Book chapter K.22. Temleitner L, Pu
Page 60 and 61: Fig. 1 Characteristics of surface p
Page 62 and 63: M. LASER PHYSICS K. Rózsa, G. Bán
Page 64 and 65: Publications Articles M.1. Sigenege
Page 66 and 67: O. LASER APPLICATION A. Czitrovszky
Page 68 and 69: Raman spectroscopy is widely used f
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Page 72 and 73: P. FEMTOSECOND LASERS R. Szipőcs,
Page 74 and 75: Grants and international cooperatio
Page 78 and 79: y optical microscopy. While in Y 2
Page 80 and 81: Publications: Articles R.1. Földv
Page 82 and 83: S. CHARACTERIZATION AND POINT DEFEC
Page 84 and 85: groups of the Li 2 B 4 O 7 lattice.
Page 86 and 87: S.10. Lengyel K, Kovács L, Péter
Page 88 and 89: entanglement one has to find method
Page 90 and 91: T.7. T.8. T.9. Asbóth JK, Domokos
Page 92 and 93: EDUCATION Graduate and postgraduate
Page 94 and 95: Laboratory practice and seminars
Page 96 and 97: G. Dravecz (ELTE and Université de
Page 98 and 99: ⎯ K. Kamarás: Editorial Board Me
Page 100 and 101: CONFERENCES ⎯ Electrochemistry se
Page 102: TABLE of CONTENTS PREFACE 1 KEY FIG
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