Investigation and optimization of crystalline and glassy systems for data processing  Page description

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Details of project

 
Identifier
34262
Type K
Principal investigator Corradi, Gábor
Title in Hungarian Adatkezelésre alkalmas kristályos és üveges rendszerek vizsgálata és optimalizálása
Title in English Investigation and optimization of crystalline and glassy systems for data processing
Panel Physics 1
Department or equivalent Crystal Physics Dept. (Research Institute for Solid State Physics and Optics Hung. Acad. Sci.)
Participants Kovács, László
Lassányi, Péterné
Starting date 2001-01-01
Closing date 2005-12-31
Funding (in million HUF) 8.362
FTE (full time equivalent) 0.00
state closed project





 

Final report

 
Results in Hungarian
Lítium niobát kristályokat fejlesztettünk ki és jellemeztünk különböző Li/Nb aránnyal, oxidációs állapottal és adalékolással, nemlineáris optikai és holográfiai alkalmazásokhoz. Jellemeztük a beépülés rácshelyeit Er adalék esetében, mely a belső terekre érzékeny szondaként a doménfalak és koncentrációs profilok feltérképezéséhez is használható. Az OH- ionok beépülési módjainak - LiTaO3-ban és SBN-ben is elvégzett - infravörös vizsgálatával igazoltuk, hogy a hologramok termikus fixálása és lebomlása LiNbO3-ban protondiffúzión alapul. Meghatároztuk a nemlineáris optikai konstansokat LiNbO3 és egyes borát kristályok esetében. Kimutattuk, hogy a fotorefraktív érzékenység megszűntetésére alkalmas Mg küszöbkoncentráció lecsökken, ha a Li/Nb arány kongruenstől sztöchiometrikus felé tolódik, és leírtuk egyes optikai paraméterek küszöb feletti változását. Megmutattuk, hogy a Ti adalék, melynek Li vagy Nb helyre történő beépülése szintén a Mg másod-adaléktól függ, a Nb alrácsban megfigyelt polaron és bipolaron állapotokhoz hasonló sekély nívókat hoz létre a tiltott sávban. Megmutattuk, hogy az Eu-mal vagy Ce-mal aktivált BaBr2 és BaCl2 egykristályok, illetve az ezeket nanokristályos zárványként tartalmazó halid-cirkonát üvegkerámiák röntgenkép-tároló anyagként előnyösen alkalmazhatók. EPR és fotostimulációt is alkalmazó lumineszcencia méréseink alapján megmagyaráztuk a beírás és kiolvasás mechanizmusát, valamint az ezzel kapcsolatos töltésbefogási folyamatokat.
Results in English
Lithium niobate crystals with controlled Li/Nb ratios, oxidation states and dopings have been developed and characterized for nonlinear optical and holographic applications. Different sites of Er probes mapping internal fields in domain walls and concentration profiles have been characterized. Thermal fixing of holograms has been shown to be due to proton diffusion based on parallel infrared studies of the composition dependent incorporation of OH ions, observed also in LiTaO3 and SBN crystals. Non-linear optical constants of LiNbO3 and some borate crystals have been determined. The Mg threshold concentration sufficient for the suppression of photorefractive sensitivity has been shown to diminish for LiNbO3 with compositions changing from congruent to stoichiometric. Optical properties of above-threshold crystals have been described. Ti incorporation on Li or Nb site, also dependent on Mg co-doping, was shown to introduce shallow levels in the gap similar to polaron and bipolaron states observed on Nb sites. BaBr2 and BaCl2 single crystals activated by Eu or Ce doping, viz. halide-zirconate glasses containing these crystalline phases as nano-inclusions, have been shown to be efficient materials for prospective X-ray storage phosphor applications. The mechanisms of writing and read-out and the charge trapping processes involved have been explained based on EPR and luminescence measurements including photo-stimulated emission.
Full text http://real.mtak.hu/20/
Decision
Yes





 

List of publications

 
Corradi G; Lingner Th; Kutsenko AB; Dierolf V; Polgár K; Spaeth JM; von der Osten W: Magneto-optical studies of Er3+ in LiNbO3, Rad Eff Def Solids 155: 223-227, 2001
Williams RT; Ücer KB; Yochum HM; Grigorjeva LG; Millers DK; Corradi G: Self-trapped electron and transient defect absorption in niobate and tungstate crystals, Rad Eff Def Solids 155: 265-276, 2001
Schweizer S; Corradi G; Edgar A; Spaeth JM: EPR of Eu2+ in BaBr2 crystals and fluorobromozirconate glass ceramics, J Phys Condens Matter 13: 2331-2338, 2001
Mandula G; Lengyel K; Kovács L; Ellaban MA; Rupp RA; Fally M: Thermal fixing of holographic gratings in nearly stoichiometric LiNbO3 crystals, Proceedings SPIE 4412: 226-230, 2001
Wöhlecke M; Kovács L: OH- ions in oxide crystals, Critical Reviews in Solid State and Material Sciences 25: 1-86, 2001
Klein RS; Kugel GE; Maillard A; Polgár K: Absolute non-linear optical coefficients of LiNbO3 for near stoichiometric crystal compositions, Optical Materials 22: 171-174, 2003
Klein RS; Kugel GE; Maillard A; Sifi A; Polgár K: Absolute non-linear optical coefficient measurements of BBO single crystal and determination of angular acceptance by second harmonic generation, Optical Materials 22: 163-169, 2003
Dierolf V; Sandmann C; Gopalan V; Kim S; Polgár K: Ferroelectric domain imaging by defect luminescence microscopy, J Appl Phys 93: 2295-2297, 2003
Dierolf V; Sandmann C; Gopalan V; Kim S; Polgár K: Rearrangement of rare earth defects under domain inversion in LiNbO3, Rad.Eff Defects Solids 158: 247-250, 2003
Dierolf V; Morgus T; Sandmann C; Cantelar E; Cusso F; Capek P; Spirkova J; Polgár K; Sohler W; Ostendorf A: Comparative studies of Er3+ ions in LiNbO3 waveguides produced by different methods, Rad.Eff Defects Solids 158: 263-267, 2003
Sifi A; Klein RS; Maillard A; Kugel GE; Péter Á; Polgár K: Absolute non-linear optical coefficient measurements of CsLiB6O10 single crystals by second harmonic generation, Optical Materials 24: 431-435, 2003
Klein RS; Kugel GE; Maillard A; Polgár K: Considerations of angular acceptance and non-linear optical coefficient measurements by second harmonic generation in LiNbO3 crystals, Ferroelectrics 296: 57-66, 2003
Bugaychuk S; Rupp RA; Mandula G; Kovács L: Soliton profile of the dynamic grating amplitude and its alteration by photorefractive wave mixing, Trends in Optics and Photonics 87: 404-409, 2003
Bäumer C; David C; Betzler K; Hesse H; Lengyel K; Kovács L; Wöhlecke M: Composition dependence of the OH-stretch-mode spectrum in lithium tantalate, phys stat sol (a) 201: R13-16, 2004
Corradi G; Secu M; Schweizer S; Spaeth JM: Luminescence properties of the X-ray storage phosphor BaBr2:Ce3+, J Phys Condens Matter 16: 1489-1500, 2004
Corradi G; Meyer M; Kovács L; Polgár K: Gap levels of Ti3+ on Nb or Li sites in LiNbO3:(Mg):Ti single crystals and their effect on charge transfer processes, Appl Phys B 78: 607-614, 2004
Corradi G; Secu M; Schweizer S; Spaeth JM: Photoluminescence and photostimulated luminescence in the X-ray storage phosphor BaBr2 doped with cerium, Rad Measurements 38: 511-514, 2004
Pálfalvi L; Hebling J; Almási G; Péter Á; Polgár K; Lengyel K; Szipőcs R: Nonlinear refraction and absorption of Mg doped stoichiometric and congruent LiNbO3, J Appl Phys 95: 902-908, 2004
Polgár K; Péter Á; Ferriol M: Phase relations in the growth of stoichiometric lithium niobate, phys stat sol (a) 201: 284-288, 2004
Cochez M; Ferriol M; Pöppl L; Polgár K; Péter Á: Ternary system Li2O-K2O-Nb2O5 Part I: Phase equilibria around the lithium niobate existence field, J. Alloys Compounds 386: 238-245, 2005
Péter Á; Polgár K; Ferriol M; Pöppl L; Földvári I; Cochez M; Szaller Zs: Ternary system Li2O-K2O-Nb2O5 Part II: Growth of stoichiometric lithium niobate, J Alloys Compounds 386: 246-252, 2005
Corradi G; Meyer M; Polgár K: Bipolarons localised by Ti dopants in reduced LiNbO3 crystals double-doped by Ti and Mg, phys stat sol (c) 2: 132-135, 2005
Lengyel K; Kovács L; Péter Á; Corradi G; Polgár K: UV and IR absorption studies in LiNbO3:Mg crystals below and above the photorefractive threshold, phys stat sol (c) 2: 171-174, 2005
Selling J; Schweizer S; Spaeth JM; Corradi G; Edgar A; Williams GVM: Radiation defects in Ce-doped BaCl2 and fluorochlorozirconate glass-ceramics X-ray storage phospors, phys stat sol (c) 2: 592-595, 2005
David C, Tunyagi A, Ulex M, Wöhlecke M, Betzler K; Lengyel K; Kovács L: Structure of the OH– stretching vibrational band in SrxBa1–xNb2O6, J Appl Phys 95: 5522-5526, 2004
Selling J; Corradi G; Secu M; Schweizer S: Comparison of the luminescence properties of the x-ray storage phosphors BaCl2:Ce3+ and BaBr2:Ce3+, J Phys Condens Matter 17: 8069-78, 2005
Lengyel K; Kovács L; Péter Á; Polgár K; Corradi G; Baraldi A: Temperature dependence of the OH absorption bands in LiNbO3:Mg crystals at the photorefractive threshold, In: Technical Digest of the International Workshop Lithium Niobate from material to device, from device to system, Metz, France, 23-25 May, 2005; pp. 153-154, 2005




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