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1.
Marina Lulla Jelena Asari Jaan Aarik Kaupo Kukli Raul Rammula Unto Tapper Eero Kauppinen Väino Sammelselg 《Mikrochimica acta》2006,155(1-2):195-198
Quantitative electron probe microanalysis of highly insulating materials is a complicated problem, partially solved by coating
samples with grounded thin conductive layers or using novel scanning electron microscopy (SEM) techniques, such as low-voltage
and/or variable pressure SEM. In this work, some problems of quantitative X-ray microanalysis of thin HfO2 films, in particular the possibility to determine mass thickness correlated to the density of the layer material, are discussed.
For comparison, Al2O3, Ta2O5 and TiO2 films grown onto both semiconductive Si and insulating quartz substrates were also analysed. All the films studied were synthesized
by atomic layer deposition method. 相似文献
2.
Aleksander A. Kubicki Piotr Bojarski Marek Grinberg Micha? Sadownik Benedykt Kukliński 《Optics Communications》2006,263(2):275-280
Apparatus to study time-evolution of emission spectra over very wide time and spectral range is described. Excitation part of the equipment consists of solid state Nd:YAG laser and optical parametric generator. The heart of the detection system consists of spectrograph and streak camera. The significance of optics and electronics built in the system for proper, fast and convenient measurements is underlined. The results of donor-acceptor energy transfer in a rigid polyvinyl alcohol matrix serve here as an example of application our equipment to study complex systems. 相似文献
3.
S. Mahlik B. Kukliński Y.M. Yen R.S. Meltzer M. Grinberg 《Journal of luminescence》2008,128(5-6):715-717
The 4f65d1(e)→4f7 emission (normal) of Eu2+ in SrF2 and normal and anomalous emissions of Eu2+ in BaF2 are studied as a function of pressure and temperature. Although in BaF2 both emissions (anomalous and normal) shift with pressure in the same spectral direction (a red shift), the anomalous emission converts to the normal emission when the pressure increases to 33 kbar. Considering the dependence of BaF2:Eu2+ luminescence on the pressure and temperature we have found that spectral transformation takes place due to a smooth pressure-induced level crossing at approximately the same pressure as the phase transition. 相似文献
4.
The luminescence excitation spectra, emission spectra under photo- and X-ray excitation, luminescence decay kinetics and thermostimulated luminescence (TSL) of Gd3Ga5O12 garnet (GGG) polycrystalline samples have been investigated. It was established that the spectrum of Cr3+ ion emission were present in all TSL peaks. The activation energies of traps that are responsible for appearance of TSL in the region 295-600 K were estimated. It is shown that delocalization of electrons from the Cr3+e traps leads to the appearance of thermoluminescence (TL) glow peak at 390 K. The nature of other TSL peaks is discussed. The influence of visible light on the TSL intensity of the preliminary X-ray-irradiated samples is shown. 相似文献
5.
We report high-pressure luminescence spectroscopy studies of Ti3? in Al2O3 and YAlO3. High-pressure luminescence spectra were measured for Al2O3:Ti3? up to 90kbar and for YAlO3:Ti3? up to 181 kbar. In both cases, a blue shift of the luminescence peak with pressure was observed and is attributed to an increase in the octahedral crystal-field strength (10 Dq) with pressure. In the case of YAlO3;Ti3?, an additional luminescence peak was observed at 181 kbar and below ~ 200 K, and is attributed to a metastable state. The metastability of the 2E excited state was induced by pressure that removes the equivalency of three energy minima of the 2E state coupled to the ? mode. 相似文献
6.
Kaupo Kukli Mikko RitalaMarkku Leskelä Timo SajavaaraJuhani Keinonen David GilmerSandeep Bagchi Lata Prabhu 《Journal of Non》2002,303(1):35-39
Ta2O5, Ta-Nb-O, Zr-Al-Nb-O, and Zr-Al-O mixture films or solid solutions were grown on Si(1 0 0) substrates at 300 °C by atomic layer deposition. The equivalent oxide thickness of Ta2O5 based capacitors was between 1 and 3 nm. In Zr-Al-O films, the high permittivity of ZrO2 was combined with high resistivity of Al2O3 layers. The permittivity, surface roughness and interface charge density increased with the Zr content and the equivalent oxide thickness was between 2.0 and 2.5 nm. In the Zr-Al-Nb-O films the equivalent oxide thickness remained at 1.8-2.0 nm. 相似文献
7.
A.A. Wronkowska A. Wronkowski K. Kukliński M. Senski ?. Skowroński 《Applied Surface Science》2010,256(15):4839-4844
Optical properties and phase composition of In-Au and Sn-Ag ultra-thin films grown by sequential evaporating and co-depositing of metals in a vacuum were investigated combining X-ray diffraction and spectroscopic ellipsometry methods. The atomic concentration ratios of bilayer and co-deposited samples were the same, i.e. In(Sn):Au(Ag) = 1:2. The XRD patterns indicated creation of AuIn, AuIn2, Au3In2, Au9In4 and Ag3Sn intermetallic compounds at room temperature. The effective complex dielectric functions of the composite layers, , were determined from ellipsometric quantities Ψ and Δ measured in a photon energy range of 0.6-6.5 eV. The free-carrier parameters (unscreened plasma frequency and free-carrier damping) and optical resistivity were evaluated using a semiclassical Drude-Lorentz model of the effective dielectric function. There was noticed a distinct influence of phase composition and surface morphology on the optical constants and conductivity of the samples: ρop changed from approximately 15 μΩ cm to 37 μΩ cm for Ag-Sn structures, composed of β-Sn and Ag3Sn phases, and from 21 μΩ cm to 83 μΩ cm for Au-In multiphase system. Lower resistivity demonstrated diffusive layers formed after deposition of an In(Sn) thin film on the noble metal underlayer. 相似文献
8.
The intrinsic luminescence of glasses of the CaO–Ga2O3–GeO2 system has been investigated. High chemical purity and optical quality glasses, both undoped and doped with transition and rare-earth ions with different compositions, were obtained by high-temperature synthesis. The influences of the basic glass composition, impurities (Cr3+, Mn2+, Eu2+, Nd3+, Ho3+, Er3+, and Ce3+) and different kinds of excitation, on the intrinsic luminescence of the CaO–Ga2O3–GeO2 glasses were investigated. The nature and possible mechanisms of the intrinsic luminescence in glasses of this system are discussed. The proposed models of intrinsic luminescence are supported by electron spin resonance spectroscopy. 相似文献
9.
B.V. Padlyak Cz. Koepke D. Piatkowski K. Wisniewski B. Kukliński 《Journal of Non》2009,355(24-27):1338-1341
3CaO–Ga2O3–3GeO2 glass excited state absorption spectra-activated with Ho3+ (Ho2O3 – 0.7 wt% content) have been measured and analysed. Up-converted emission channels have been identified and the predicted up-converted emission bands have been registered under Ar ion laser (λ = 488 nm) excitation according to the excited state absorption data. A mechanism of up-converted transitions for Ho3+ centres in this prototype glass network is proposed on the basis of the obtained results. 相似文献
10.
S. Dueñas H. Castán H. García L. Bailón K. Kukli J. Lu M. Ritala M. Leskelä 《Journal of Non》2008,354(2-9):404-408
Routes to atomic layer-deposited TiO2 films with decreased leakage have been studied by using electrical characterization techniques. The combination of post-deposition annealing parameters, time and temperature, which provides measurable aluminum–titanium oxide–silicon structures – i.e., having capacitance–voltage curves which show accumulation behavior – are 625 °C, 10 min for p-type substrates, and 550 °C, 10 min for n-type substrates. The best annealing conditions for p-type substrates are 625 °C with the length extended to 30 min, which produces an interfacial state density of about 5–6 × 1011 cm?2 eV?1, and disordered-induced gap state density below our experimental limits. We have also proved that a post-deposition annealing must be applied to TiO2/HfO2 and HfO2/TiO2/HfO2 stacked structures to obtain adequate measurability conditions. 相似文献