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The main goal was to monitor corrosion phenomena in the first and the most pronounced period of corrosion layer formation in duration of two weeks. For this purpose two ion beam techniques (PIXE and RBS) were used to define the general stoichiometry and thickness of the sample layers. Furthermore, the X-ray absorption near edge structure (XANES) measurements were performed at the XAFS beam-line of the Elettra synchrotron. T

The position and intensity shift of the XANES spectra components during the corrosion buildup clearly discriminate Cu(0), Cu (I) and Cu (II), thus providing the copper oxidation states in the corrosion layers as a function of the exposure duration of bronze to corrosion media.

Ion tracks can be produced by swift heavy ions only if the density of the deposited energy exceeds a certain, material dependent critical value. Otherwise, the deposited energy simply dissipates away without altering the material. Therefore, thresholds for ion track formation are a prominent feature investigated in many swift heavy ion irradiation studies. The values of the thresholds can vary a lot between different materials, and for thorough ion track studies, very high-energy swift heavy ions have to be used. In the present contribution, we present several examples how the accelerator facility at the Ruđer Bošković Institute in Zagreb has been used for ion track studies. These examples will illustrate two strategies making small and medium accelerator facilities well suited for this line of research. First, the threshold for ion track formation depends on the electronic stopping power that is a highly nonlinear function of the total kinetic energy of the swift heavy ion. Therefore, investigations of the ion track formation close to the threshold can be outsourced to smaller accelerator facilities, thus saving considerably on beamtimes at large facilities. Additionally, thresholds can be lowered in several ways, for example, by applying grazing incidence ion irradiation [1, 2]. Also, defects introduced into the material via low energy irradiation can reduce the threshold for ion track formation [2]. Other thermally driven processes like assembly and modification of quantum dot lattices can require only moderate stopping powers [3]. Second, ion beam analysis of materials is in widespread use at the small and medium sized accelerator facilities. Some of these techniques are sensitive to the amount of defects in the material, like RBS/c and ionoluminiscence. Other techniques, like high resolution PIXE can provide information about early stages of ion track formation. Here we present several examples how these techniques can be used advantageously for in situ ion track studies [4]. We also present first in situ RBS/c results obtained from our dual-beam end station.

Materials consisting of semiconductor core-shell nanostructures, like nanowires or quantum dots attract special attention due to their highly adjustable electronic structure and optical properties. Especially interesting for the application of such materials in solar cells is the fact that Ge/Si cor/shell quantum dots(QD) have a type II band alignment, leading to the separation of charge carriers [1, 2]. We have recently developed a method for the growth of self-assembled core/shell Ge/Si QDs in an amorphous alumina matrix [3, 4], but it can also be done in SiC and Si3N4 matrices. Depending on the matrix type, different deposition conditions are needed for the quantum dots to form. Furthermore, the matrix type greatly influences the transport properties. Different matrices produce different transport barriers between the QDs, with tunneling probability heavily dependent on the height of the barrier. Here were port the influence of the deposition conditions on the QD formation in all matrices, as well as the effect of the matrix type on the electrical properties.

Core-shell structured Ge nanoparticles (quantum dots) with metallic shells (aluminium, tantalum and titanium) in an amorphous alumina matrix were investigated. The presence of metallic shells just a few atoms in thickness has shown to radically weaken oxidation of germanium but occurrence of intermixing Ge-metal or Ge-metal-O phases is implied. Greater amounts of metal in some samples caused shells to overlap forming a slab-like structure also causing loss of self- assembly. In addition, these metallic shells dramatically influence the dielectric function and absorption coefficient. Most important absorption peak energies in investigated systems are in the relevant part of solar spectrum (1 - 4.5 eV) which suggests applications of these materials in photovoltaic devices are possible. Samples with self-assembled super-lattice were created using magnetron sputtering at 300°C. Characterization methods used are Elastic recoil detection (ERDA), Transmission electron microscopy (TEM), Grazing incidence small angle X-ray scattering (GISAXS), X-ray absorption near edge structure (XANES), Raman spectroscopy and Ellipsometry.

Kavzi-dvodimenzionalan sustav niklenih nanočestica unutar izolatorske Al2O3 matrice pripremljen je u obliku tankog filma metodom naizmjenične magnetronske depozicije Al2O3+Ni i Al2O3 slojeva na Si(100) supstratu. Niklene nanočestice nastaju mehanizmom samoorganiziranog rasta pod utjecajem difuzije i površinske morfologije. Strukturna istraživanja pokazala su usku raspodjelu velicina Ni cestica te njihov pravilan razmještaj u 3D rešetku. Mjerenja magnetskih svojstava ukazuju na kompleksnu dinamiku magnetskog momenta na niskim temperaturama ukljucujući blokiranje magnetskog momenta i ireverzibilnost. Takoder, uočena je značajna anizotropija magnetskih svojstava prilikom mjerenja s primjenjenim magnetskim poljem paralelno, odnosno okomito na površinu tankog filma. Anizotropija je objašnjena nezanemarivim magnetskim dipol-dipol međudjelovanjem između Ni čestica, koja također utječe i na dinamiku sustava. Utjecaj dipol-dipol međudjelovanja na magnetsko ponašanje sustava potvrdeno je simulacijama M(H) krivulja, koje su provedene pomoću Monte Carlo metode.

By classical definition, zeolites are crystalline alumosilicate materials with well-defined system of channels and cages having size lower than 2 nm. This definition was further extended to all materials possessing structure features typical for zeolites, so called zeotypes. Zeotypes are built of tetrahedra of oxygen atoms bonded to central T atom (T = Si, Al, Zn, Ge, P, Ga, …) and connected via vertices thus forming porous framework. Taking into account possible bonding angles and energy restrictions, there are over two millions hypothetical zeolite structures. Zeolites are widely used materials, ranging from ion-exchange and molecular sieving to catalysis in oil refinement and drug delivery in medicine. For this reason engineering of their structure and properties in line with the requirements of a particular application would be beneficial for improving their performance. In spite of numerous studies performed in this field, still many of the results are based on empirical experience, rather than on profound comprehension of the basic processes of zeolite formation. It was perceived that some zeolite building units are more often formed in the presence of a certain T-atom than when others are used (1). Besides, depending on the synthesis conditions applied, different final products can be formed from the same initial reaction system (2). Herein we report the study of zincosilicte RUB-17 – three-membered ring containing framework type RSN (3). The methods employed to study the precursors and final products are XRD, GISAXS, TG, Raman, IR, UV/VIS and NMR spectroscopy. The effect of type of the potential framework T-atoms which were found to form three- membered rings in zeolite frameworks (Al, B, Ge, Li and Mg) is investigated. The collected data indicate that under studied conditions the RSN framework is formed exclusively in zinc containing systems. In order to get more insight into RSN formation several different zinc sources are used. Besides the synthesis conditions the necessity of the presence of structure directing agent in the RUB-17 reaction mixture is going to be discussed. The obtain data can be used for control of zeolite formation in similar systems. In addition, the potential of the prepared material to be used as semiconductor is investigated.

Zbog svoje velike kineticke energije, brzi teški ioni mogu pravocrtno prodrijeti duboko u materijal. Ovo njihovo svojstvo je posebno pogodno za nanostrukturiranje površina [1-5] i 2D materijala [6, 7] kada se zracenje vrši pod malim kutom u odnosu na površinu, cime se postiže veliki prijenos energije iona na odreženu površinu. Uz kratak pregled dosadašnjih postignuca, u ovom doprinosu predstavit ce se i novi eksperimentalni rezultati nanostrukturiranja površina materijala koji su otporni na ionsko zracenje (MgO, Al2O3, MgAl2O4), te koncept grafen-polimer kompozitne nanomembrane proizvedene pomocu zracenja brzim teškim ionima i naknadnog jetkanja [6-8].

Višerječni izrazi čine značajan udio vokabulara prirodnoga jezika, no zbog specifičnosti i nepredvidivosti obilježja, iziskuju posebnu pažnju pri razvoju sustava za automatsku identifikaciju izraza u sklopu računalne obrade prirodnog jezika. U sklopu ovoga rada, razvijen je i predstavljen sustav za identifikaciju višerječnih izraza koji iz hrvatskog korpusa tekstova ekstrahira i klasificira potencijalne višerječne izraze kombinacijom statističkih mjera i lingvističkih značajki specifičnih za višerječne izraze. Opisan je izračun vrijednosti značajki, struktura Bayesove mreže za klasifikaciju i rezultati vrednovanja u ovisnosti o određivanju zavisnosti među značajkama. Multiword expressions constitute a significant portion of any natural language vocabulary, but due to their characteristic idiosyncrasy, MWEs call for particular dedication in the development of applications for automatic identification, within the scope of automated natural language processing. In this thesis, we develop and present a multiword expression identification system that extracts and classifies potential MWEs through a combination of statistical measures and linguistic features specific to MWEs. We describe the computation of feature values and the structure of the Bayesian network used in classification, and present evaluation results relative to different dependency relations between features.

Astma je jedna od najčešćih bolesti respiratornog sustava. Vodeći je uzrok obolijevanja i smrti širom svijeta. Procjenjuje se da više od 20% stanovništva boluje od alergijskih bolesti poput alergijske astme, konjunktivitisa, rinitisa, atopijskog dermatitisa i anafilaksije. Alergijska astma je najčešći tip astme u dječjoj i odrasloj dobi. To je kronična bolest sa reverzibilnom bronhalnom opstrukcijom. Opstrukcija je uzrokovana upalom, edemom i kontrakcijom glatkih mišića u dišnim putevima. Alergeni koji dospiju u dišni sustav uzrokuju reakciju preosjetljivosti , luče se brojne upalne stanice i dovode do karakterističnih promjena. Najčešći alergeni koji uzrokuju napadaje su pelud, prašina, životinjska dlaka, različite trave. Simptomi asmatskog napadaja su dispneja, kašalj, visokotonsko zviždanje tijekom ekspirija praćeno stezanjem u prsima ili kombinacija ovih simptoma. Asmatski status je naziv za napad koji dugo traje, progresivan je i ne reagira na terapiju. Potrebna je hospitalizacija jer može dovesti do smrtnog ishoda. Dijagnostika, kasifikacija i kontrola astme su definirani Globalnom inicijativom za astmu (GINA). Alergijska astma se dijagnosticira anamnezom, kliničkim pregledom, krvnim pretragama, alergijskim testovima i spirometrijom (zlatni strandard). Liječenje uključuje izbjegavanje alergena i farmakološku terapiju (bronhodilatatori, kortikosteroidi). U kontroli astme važna je edukacija, pravilno uzimanje lijekova, vježbe disanja i relaksacije i izbjegavanje uzročnih faktora., Asthma is very common disease of respiratory system. It is the leading cause of morbidity and mortality throughout the world. It is estimated that over 20% of world population suffers from allergic diseases such as allergic asthma, conjunctivitis, rhinitis, atopic dermatitis and anaphylaxis. Allergic asthma is the most common type asthma in children and adults. It is chronic disease with reversible bronchial obstruction. The obstruction is caused by inflammation, edema and smooth muscles contractions in airways. Allergens inhaled in airways cause hypersensitive reaction, many inflammation cells are produced and all that leads to characteristic changes. The most common allergens that cause attacks are pollen, dust, animal hair, some plants. The symptoms of asthma attack are dyspnea, cough, high tone wheezing during expiration followed with chest squeezing, or with combination of those symptoms. Status asthmaticus it is a term for progressive, long lasting attack that does not respond to usual therapy. Hospitalization is necessary because it can lead to death. Diagnostics, classification and control of asthma are defined by Global Initiative for Asthma (GINA). Allergic asthma is diagnosed by history, clinical examination, blood and allergy tests and spirometry (gold standard). The treatment includes avoiding of allergens and pharmacotherapy (bronchodilatators, corticosteroids). Asthma can be controlled with regular education and drug use, breathing and relaxation exercises and avoidance of causative factors.

Swift heavy ion (SHI) irradiation emerged as a versatile tool to modify material properties on the nanoscale, due to the very intense yet extremely localized excitation of the material. Even single ion impacts can induce drastic changes in materials in the SHI regime (m > 15 u, E > 0.1 MeV/u). Nanoscale material transformation along the SHI trajectory, that is straight and several micrometers long, is in essence derived from a 1D excitation source. This feature is in particular interesting for structuring 2D materials and surfaces, when a SHI beam is applied under grazing angles of incidence [1, 2, 3, 4]. In the first part of our contribution, we present recent advances in surface modifications using SHIs. Novel features of the ion impact sites morphology we found in GaN [5], ITO thin films [6], and rutile TiO2 [7]. Graphene as a special material shows also a great deal of susceptibility to SHI irradiation, and nanoscale modifications with the shapes of ruptures and foldings were reported [3]. The threshold for this kind of nanostructuring was recently established [8], and we demonstrated that even small scale accelerators can be utilized for this purpose. In the second part we present several advances in materials analysis using SHI beams. These include elastic recoil detection analysis of nanoscale multilayers, in situ Rutherford backscattering in channeling for defect analysis, and imaging of biological samples using MeV-SIMS. [1] E. Akcöltekin, T. Peters, R. Meyer, A. Duvenbeck, M. Klusmann, I. Monnet, H. Lebius, M. Schleberger, Nature Nanotech. 2 (2007) 290. [2] M. Karlušić, S. Akcöltekin, O. Osmani, I. Monnet, H. Lebius, M. Jakšić, M. Schleberger, New J. Phys. 12 (2010) 043009. [3] S. Akcöltekin, H. Bukowska, T. Peters, O. Osmani, I. Monnet, I. Alzaher, B. Ban d’Etat, H. Lebius, and M. Schleberger, Appl. Phys. Lett. 98 (2011) 103103. [4] O. Ochedowski, O. Osmani, M. Schade, B.K. Bussmann, B. Ban d’Etat, H. Lebius, M. Schleberger, Nature Comm. 5 (2014) 3193. [5] M. Karlušić, R. Kozubek, H. Lebius, B. Ban d’Etat, R.A. Wilhelm, M. Buljan, Z. Siketić, F. Scholz, T. Meisch, M. Jakšić, S. Bernstorff, M. Schleberger, and B. Šantić, J. Phys. D: Appl. Phys. 48 (2015) 325304. [6] M. Karlušić et al., unpublished. [7] M. Karlušić, S. Bernstorff, Z. Siketić, B. Šantić, I. Bogdanović-Radović, M. Jakšić, M. Schleberger, M. Buljan, J. Appl. Cryst. (submitted). [8] O. Ochedowski, O. Lehtinen, U. Kaiser, A. Turchanin, B. Ban-d’Etat, H. Lebius, M. Karlušić, M. Jakšić, M. Schleberger, Nanotechnology 26 (2015) 465302.

Swift heavy ions have found widespread use in research and technology, for both materials analysis and modification. Having a kinetic energy in the MeV range and above, their usability now spans diverse fields such as hadron therapy, industrial production of track etched membranes and testing of electronic devices against single-event upsets. Impact of the swift heavy ion leads to intense heating of the material due to electron–phonon coupling and often triggers melting in a nanoscale volume along the ion trajectory. Upon rapid resolidification, permanent damage called an ion track is formed. At the surface, various nanostructures can be found on the position of the ion impact by means of atomic force microscopy. In recent years particular attention was given to grazing incidence swift heavy ion irradiation that yields ion tracks on the surface in the form of long chains of nanodots. In the present contribution we show that such ion tracks on the surfaces can be also investigated by grazing incidence small angle X-ray scattering. Examples of the observation of surface ion tracks on GaN and TiO2 surfaces are presented.

Recently we have demonstrated a new approach for the investigation of ion tracks in amorphous materials using grazing incidence small angle X-ray scattering (GISAXS). Furthermore, ion tracks in those materials exhibit typical specifics like the velocity effect. In this contribution new developments are presented. Irradiation of flat solid surfaces by swift heavy ions (SHI) under grazing incidence can result in the formation of surface ion tracks that are usually observed directly using atomic force microscopy (AFM). Here we introduce a new approach based on the GISAXS technique, used for the structural analysis of surface tracks. In addition, we show how grazing incidence SHI irradiation can be used to produce nanoscale ripples. Compared to our previous work where 15 MeV Si4+ was the most energetic ion beam used, in the present work our research was extended to higher values of electronic energy loss by using 23 MeV I6+ and 92 MeV Xe23+ ion beams. New ion track phenomena were observed after 92 MeV Xe23+ irradiation: after the grazing incidence irradiation, nanostripes were observed on the surface, while after irradiation under oblique angles, evidence for nucleation of nanoparticles by single ions was found.

The damage which is produced when a swift heavy ion passes through solid material is called an ion track. Its cylindrical shape originates from the long range of the penetrating ion while at the same time the ion induced damage remains localized close to the ion trajectory. Such nanoscale damage can be observed directly by means of TEM and AFM, but there are also number of other techniques that can be used to characterize ion tracks indirectly. One of the most utilised techniques for indirect measurement of ion tracks is RBS/channelling. However, this ion beam analysis (IBA) technique is not available at large ion accelerator facilities where ion track studies are mostly done. Recent commissioning of the dual ion beam chamber at the RBI, Zagreb opens up an opportunity to study kinetics of ion track formation using in-situ RBS/c. Ion track formation is accomplished using swift heavy ions delivered by the 6 MV EN Tandem Van de Graaff accelerator, while simultaneously RBS/c measurement is done using proton beams delivered from the 1 MV Tandetron. This approach is especially important for studies close to the ion track formation threshold, where deviations from simple overlap track models are expected. To accomplish this, a substantial amount of experimental data is needed for reliable analysis and this novel approach provides adequate solution to this challenge. Another approach for in-situ IBA is to use swift heavy ions for simultaneous material modification and monitoring using ERDA. As shown recently, monitoring elemental changes in the sample, ion track characterisation can be accomplished. We present two applications of ERDA: a) monitoring stoichiometry changes during ion track formation in GaN and b) hydrogen loss in amorphous Al2O3 thin films.

Swift heavy ion (SHI) irradiation is a powerful tool for materials modification on the nanoscale. When irradiated at grazing incidence angle, surface modifications in the form of long surface ion tracks can be observed [1, 2, 3]. Recently, it was demonstrated that grazing incidence SHI irradiation can also be applied for modification of graphene [4] and other 2D materials. In the present contribution, we present two new developments along this line of research, demonstrating the usability of SHI for nanoscale modifications of surfaces and custom made 2D materials. Grazing incidence SHI irradiation of GaN [5] yields the formation of two different kinds of surface ion tracks. While chains of nanohillocks were observed for higher values of electronic stopping power, chains of nanoholes were found by AFM for lower stopping power values. In addition, surface tracks were investigated using grazing incidence small angle X-ray scattering (GISAXS). This novel method yields good statistics and avoids typical difficulties in measurements due to the (unknown) AFM tip size. Preferential loss of nitrogen found by in situ TOFERDA measurements indicates a thermal decomposition of GaN as origin of the chains of nanoholes observed on its surface. Second experiment shown is grazing incidence SHI irradiation of thin ITO films. Here we also found two different surface ion track morphologies: for lower stopping powers, usual ion tracks were observed, but for high stopping power values nanostripes in the form of double tracks were found (Fig. 1a). After higher fluence SHI irradiation, yet another new feature was found: in a narrow range of stopping powers, straight uniform nanoscale ripples were observed for the first time (Fig. 1b.).

Ion-irradiation of materials is a powerful tool for the design of their properties via changes induced within the ion tracks. Characterization of these changes is usually difficult, especially if the tracks are completely or partially below the surface as well as in amorphous systems where the contrast between the track and the surrounding material is low. Therefore, a simple and efficient method for the characterization of ion beam induced changes and all similar effects in materials is of great importance. Here we present models and a program for the analysis of different types of ion-irradiation induced tracks at the material surface or just below it by GISAXS (grazing incidence small angle x-ray scattering). The structure of the formed tracks is often non-continuous, i.e, the tracks consist of nano-sized structures aligned along the ion beam trajectory. The proposed method allows determination of all important ion track properties inc1uding their structure, shape, size, separation as well as all properties of the formed nano-objects for the non-continuous tracks. The efficiency of the method is demonstrated using ion tracks produced in Ge+ITO mixture film irradiated by 15 MeV Si ions. The developed models are incorporated into a new freely available program GISAXStudio for processing and analysis of materials modified by ion beams using GISAXS.

Simple methods for fabrication of semiconductor quantum dots in transparent oxide matrices play an important role in various nanotechnology applications. Here we present a method for the low-temperature production of closely packed crystalline Ge QDs embedded in ITO matrix. The films are produced by magnetron sputter deposition followed by thermal annealing. The crystallization of Ge is found to occur already at 300°C, which is significantly lower than the crystallization temperature of Ge produced by the same method in silica or alumina matrices. The dependencies of the conductivity of the films and their optical properties on the materials structure, Ge content in the ITO matrix and the annealing conditions are demonstrated. The crystallization of Ge causes a huge increase in the films conductivity and it also affects the films optical properties.

The passage of a swift heavy ion through a solid material can result in permanent damage called ion track. The most common description of the ion track formation, the thermal spike model, suggests that the kinetic energy of the projectile that is deposited as dense electronic excitation along the ion trajectory, can lead to melting of the material. In this case, ion tracks originate from the quenching of the molten phase on the nanosecond time scale, resulting in an amorphous inclusion. Thus, the threshold for ion track formation and the track size depend on ion beam parameters and material properties. One of the most important material properties related to the swift heavy ion track formation is the energy bandgap [1, 2]. In this work we present experimental results of ion track formation in thin GaN epi-layer grown by MOVPE on sapphire. As a follow up of our previous work on the wide bandgap semiconductors SrTiO3 (Eg = 3 eV) [3] and TiO2 (Eg = 3 eV), the material investigated here presents an opportunity for further studies since its bandgap energy is Eg = 3.4 eV. The GaN samples were irradiated by swift heavy ions under both normal and grazing angle of incidence. Irradiation parameters were chosen to investigate the material’s response close to the ion track formation threshold, and to complement previous works using higher energy ion beams [4, 5]. We investigated ion irradiation effects both on the material surface by means of AFM and GISAXS and in the bulk by means of RBS/c. Our results are discussed in the framework of the thermal spike model. [1] M. Toulemonde et al., Nucl. Instrum. Meth. B 166-167, 903 (2000). [2] G. Szenes, Nucl. Instrum. Meth. B 269, 2075 (2011). [3] M. Karlušić et al., New J. Phys. 12, 043009 (2010). [4] S. Mansouri et al., Nucl. Instrum. Meth. B 266, 2814 (2008). [5] S.O. Kucheyev et al, J. Appl. Phys. 95, 5360 (2004).

We present an interim report on transport properties investigation on multilayers composed of 1100 nm thin film of germanium amorphous nanowires grown in alumina deposited on the glass covered with 34 nm ITO layer. We found that the transport properties, the resistivity and thermopower measured from 4 K to 320 K, are mainly determined by the ITO nanolayer, but, at the moment, it is not clear why the transport properties data show Kondo like behavior below 50 K. The additional experiments and the corresponding discussions by which we are trying to reveal the underlying physics which leads to the Kondo like behavior will be presented. We also discuss mutual impact of the layers on the transport properties.

Regularly ordered semiconductor nano-objects embedded in glass matrices show very interesting properties and have many relevant applications. Therefore, the simple and efficient methods for production of such materials are of great importance. Here we present the conditions for controlled production of self-assembled Ge-nanowires in amorphous-glass Al2O3 matrix by a simple magnetron sputtering deposition. The wires are arranged in networks with controllable structural parameters. In that way is possible to control the length and cross-section of the wires between the neighboring nodes. Such structural properties strongly affect the electrical properties of the prepared materials. We show the dependence of electrical conductivity on the Ge nanowire network structure. The electrical conductivity show strong dependence on the Ge concentration and it is also affected by the preparation conditions.

We present the investigation of self-organization and physical properties of Ni nanoparticles within the dielectric matrix prepared by the simple method of sequential magnetron sputtering deposition of two alternating Al_2O_3 and Ni+Al_2O_3 layers. The self-assembly mechanism of nanoparticle growth results in the uniform nanoparticle sizes and their regular arrangement in the 2D/3D lattice via the combination of diffusion and surface morphology effects. We investigate the dependence of the structural and magnetic properties of the formed lattices on various deposition conditions. The structure of the films was analyzed using Grazing Incidence Small and Wide Angle X-ray Scattering, and Time- of-Flight Elastic Recoil Detection Analysis measurements, while the magnetic properties were studied by SQUID magnetometry. The obtained results are important for the tailoring of physical properties of Ni NP lattices in amorphous matrices and the applications of such materials. The prepared materials are potentially interesting for spintronic applications.

Multilayer thin films consisting of 10 bilayers of (Al2O3+Ni)/Al2O3 were deposited by magnetron sputtering onto Si(100) substrate. Nickel nanoparticles are formed inside amorphous alumina matrix by self-assembly growth process. It was determined by GISAXS measurements that nickel particles are spheroidal with diameter < 3 nm and that they form paracrystal-like body-centered tetragonal lattice. Magnetic properties of the prepared thin films were studied. Due to the nanometer size of nickel particles, their magnetic structure is single domain and they show superparamagnetic behaviour. Anisotropy of magnetic properties was observed when magnetic field is applied parallel or perpendicular to the thin film surface and it was attributed to dipole-dipole interactions between particles. This was confirmed using simulations of the M(H) curve of the 2D superlattice of the identical superparamagnetic particles, which was performed using Monte Carlo method and Metropolis algorithm.

Irradiation of flat solid surfaces by swift heavy ions under the grazing incidence angle can result in the formation of surface ion tracks. These ion tracks can be observed directly using atomic force microscopy (AFM) [1-3]. However, to extract statistical information (average ion track length, length distribution etc.), structural investigations of this type are very time consuming. In the present work we apply grazing incidence small angle X-ray scattering (GISAXS) for the structural analysis of surface swift heavy ion tracks and demonstrate its capabilities on a wide range of investigated materials (SrTiO3, TiO2, quartz and a-SiO2, amorphous Ge+SiO2 and Ge+ITO thin films). Compared to AFM, GISAXS allows short measuring times with an excellent statistics. Possible applications of surface patterning of Ge+ITO thin films using swift heavy ions, with respect to the modifications of transparent Ge+ITO electrodes for photovoltaics, will be discussed as well. [1] A. Akcöltekin et al., Nature Nanotechnology 2, 290 (2007). [2] M. Karlušić et al., New J. Phys. 12, 043009 (2010). [3] S. Akcöltekin et al., Nucl. Instrum. Meth. B 267, 1386 (2009).

We investigate the structural and photoluminescence (PL) properties of regularly ordered lattices of Ge quantum dots (QDs) formed by self-assembly in a thick film of Ge + Al2O3 mixture. The effects of annealing at different temperatures and different annealing environments (vacuum and air) are studied. We show that the regular ordering of QDs remains unchanged for annealing up to 800 oC in vacuum, while it is preserved up to 700 oC when annealing is performed in air. The inner/ crystalline structure of Ge QDs and their shape depend on the annealing conditions. The crystalline grains of g-Al2O3 form in the initially amorphous Al2O3 matrix after annealing at 800 oC. The PL spectra are found to consist of two main contributions, one from the matrix and the other from Ge QDs. Both contributions depend strongly on the annealing conditions.

Ni nanoparticles (NPs) attract lot of interest as catalyst for carbon nanotube growth, as particles forming interacting or noninteracting ensembles, optoelectronic entities, etc. We have produced self-ordered Ni NPs either on surface or embedded into the alumina or silica matrix starting from three types of nickel and alumina multilayered structures prepared by magnetron sputtering. The structure and morphology of the prepared materials have been examined by grazing-incidence small- angle scattering (GISAXS), wide-angle X-ray scattering (WAXS), atomic force microscopy (AFM), and transmission electron microscopy (TEM), while magnetic properties were measured by SQUID magnetometer. Thin Ni films deposited onto dielectric's surface exhibit markedly different particle size distribution at room temperature and at elevated temperatures. The effect of temperature on NP formation has been employed for formation of 3-dim arrays of Ni NPs in dielectric matrix. Two types of precursor materials have been used: a) multilayers consisting od alternating pure Ni and pure alumina layers, and b) multilayers consisting od alternating mixed Ni+alumina and pure alumina layers. Both types of precursor material were deposited at room temperature and at elevated temperature, and subsequently annealed. The size of the Ni NPs and their average lateral distance was controlled by the amount of Ni in the Ni- containing layer, while their cross-layer interaction was governed by the thickness of intervening dielectric spacer. That way, the magnetic properties could be controlled, as well. An example of the effects of alumina dielectric spacer thickness (6 & 2 nm) and annealing temperature (RT & 500°C) upon Ni NPs sizes and spatial distribution is shown in composite GISAXS Fig. 1. The size and spatial distributions of Ni NPs govern the supermagnetic properties of such an ensemble. An example of the blocking phenomena of superparamagnets is shown in Fig. 2 for Ni NP array in silica.

Grazing incidence small angle x ray scattering-GISAXS is versatile technique for structural characterization of nanostructured surfaces and thin films. GISAXS provides data about size, shape and arrangement of nano-objects on the surfaces or in the films, together with their statistical distributions. The technique is non-destructive and the obtained data have excellent statistics. However, the GISAXS measure a reciprocal-space distribution of the scattered intensity and the retrieval of real space information is not a trivial task. Usually, one has to use a suitable structure model, from which the reciprocal-space distribution of the scattered intensity is simulated and compared to experimental data. The basics of the GISAXS technique, as well as its application on the analysis of various systems will be presented. The measurement method and extracting of the structural parameters from the measured intensity distributions using modeling will be described. The GISAXS is especially suitable for the analysis of ordered arrays of nano-objects like lattices of nanoparticles or quantum dots. In such systems the correlations in the nanoparticle positions can be easily observed and statistically described. Therefore, the special attention will be paid to the application of GISAXS on structural analysis of three-dimensional nanoparticle lattices.

We present the formation of ordered 3D lattice of Ni nanocrystals/nanoparticles in amorphous alumina matrix achieved by a self-assembly process during a single-step magnetron sputtering deposition of Ni/Al2O3 multilayer at various substrate temperatures.