IBA from an old U-120 Cyclotron to a new 3 MV TANDETRON- a Real Challenge Dorin Dudu, Ofelia Muresan, Herman Schubert, Ion Vata DFNA-Cyclotron NIPNE (New Experiments and ideas for the 3 MV TANDETRON )

Long-term Goal New, modern R&D vision in Surface Sciences and Technology by: - New basic and applied researches in Astrophysics, Life, Environment,Earth, Archaeology Sciences and last but not least Industry/Technology - New approach in using Ion Beams in characterization of nanostructured materials - On line and off line measurements of the modifications produced by irradiation Increase the national/international attractiveness and visibility of our Institute, offering the 3 MV Tandetron as a interesting R&D infrastructure Development certified analytical services using nuclear methods: Cheaper analysis More customers and users Increase beam time (the degree of occupation) Improve the economical efficiency

Customers and Users There are two kind of customers and users: Local customers and users and external customers and users Local customers and users: - are familiarized with the IBA experiments - have not possibilities to prepare interesting samples The external customers and users are not very well familiarized with IBA methods but THEY are preparing samples and being interested in characterization of the results of applied technologies The parts must be interested in collaboration

Customer needs/requirements We cooperated with scientists involved in nanotechnologies and new material discovery/ production and we observed that they are interesting for: Chemical stoichiometry samples Element identification Layered samples structures (depth profile): - order and thickness, in μm-nm range; - chemical composition; - interfaces resulted as effect of the diffusion, migration or implantation of some ions) To not deteriorates the samples To have comparative studies on the same sample To identify the effect of technological procedures ( thermal annealing, etc)

Exemples of Fulfilling Customer Needs at U-120 Cyclotron We implemented a dedicated infrastructure for RBS at U-120 Cyclotron and methods aiming to enlarge the analytical possibilities: STOICHIOMETRY (composition) determination - Materials with form memory - Optical fiber Thickness of layers measurements -Hard nano-structured coatings (superlattices) - Structured thin deposition possible to be used in fusion experiments - Thin magnetic material ( spin valves) - Thin and thick PZT or BZT amorphous composites Depth profiling of composition - Implanted samples - Interfaces at the borders of different layers

Implementation of a dedicated infrastructure for IBA at U-120 Cyclotron Accelerated beams at U-120 Cyclotron for IBA Beam line and reaction chamber (End station) with spectroscopic chains and acquisition data system Dedicated software for experimental data processing and simulations and etalons and references used for checks and calibration

Accelerated beams at U-120 Cyclotron for IBA Particle/Energy [MeV] Intensity on target [μA] Transversal sectionApplication /2, mm 2 RBS, PIXE, analysis and controlled changes and defects induced by particles irradiation d/1,3-2, mm 2 RBS, NRA analysis 14 N + (2+) / ,11-30mm 2 RBS, ERDA analysis

Beam line and reaction chamber -Old Ortec and new NEC RC41 End station for IBA Five axes goniometer Micron deplacement Minutes rotation Many samples holder system and canal lock PC based application for movement, acquisition and data analysis

Dedicated software for experimental data processing/simulations and etalons/reference samples Thin radioactive source of 238 Pu 241 Am for calibration of SSB detector and spectroscopic chain SIMNRA software for analyzing samples AuCrSi 100nm16nm > 300μm

Dedicated software for experimental data processing/simulations and etalons/reference samples Certified etalon of 5+4 alternative layers of 56 nm Cr and Ni, having the same thickness of layers with 2% precision, deposited on Si [Red: experimental data, Blue: simulated data for deduced parameters.]

Concern for infrastructure and methods developments aiming to enlarge the analytical possibilities In order to extend the field of IBAs, we have been looking for possibilities to achieve micro beams with our cyclotron introducing a conical glass capillary (up left) into the beam line, we could achieve micro beams with reasonable intensities and acceptable quality (Energy spread, divergence etc.). Analyzing the RBS spectra of a 50nm gold foil on Al with and without glass capillary substrate results than: -initial energy and energy dispersion is conserved; -app. 15% of the output beam has an energy loss or energy degradation from the initial energy going at energies of less than 100keV

STOICHIOMETRY (composition) determination used as technological support - materials with form memory - NbNb Ni Ti C OO C Nr. strat GrosimeCompoziţie 190nmC -65% O -35% 2* Ti -47% Ni -43% Nb -10% P2 (P1 după tratament) NRA analysis of the sample before and after a thermal annealing shows a strong (app. 300nm) migration of C (contaminant) below the surface.

STOICHIOMETRY (composition) determination -optical fiber with microbeam- Stoichiometry measurement Microbeam

Thickness of layers measurements 30 o RBS cu N la 3MeV pentru proba P3 65 o 45 o 5x2straturi Zr(C)N/Ti(C)N ZrN ZrCN TiN TiCN ZrN ZrCN TiN TiCN d1d1 d2d2 ~400nm ~300 μ m Ti Si (substrat) Strat de aderenţă Measurement of the layers thickness for nano-layered samples : d 1, d 2 =15-20nm using ions of He and N

Thickness of layers measurements -spin valves- Using the simulating program SIMNRA vs. 6.05, the following structure for (a) was obtained: Mo 0,9 O 0,1 /Fe 0,25 Co 0,35 O 0,4 /Cu 1,0 / Fe 0,30 Co 0,65 O 0,05 /Fe 0,25 Mn 0,75 / Mo 0.9 O 0.1 /Si 0,33 O 0,67 on Si substrate with the corresponding layer thicknesses: 4[nm]/5,5[nm]/12,2[nm] /6[nm]/18[nm]/10[nm]/32[nm]/ By the same procedure, the elemental composition for (b) was established as: Mo 0,9 O 0,1 /Fe 0,5 Co 0,5 /Cu 1,0 /Fe 0,4 Co 0,6 /Fe 0,7 Mn 0,3 / Cu 0,9 O 0,1 on Si substrate with the thicknesses of the layers being: 3[nm]/4[nm]/6[nm]/14[nm]/15[nm]/7[nm]/

Element identification -sample containing N, O, Si,Ti,Zr,Ag,Ir-

Depth profiling of element concentration -Oxygen implanted in Si- Depth profiling of implanted O in Si before and after thermal annealing shows a 50nm migration of O layer toward inside of bulk Si

Depth profiling of element concentration -interfaces structures- Buffer layer Pt 100nm /Ti 20nm /Si A) Sample as deposited B) PtTiSi interface after annealing at 800 o C B A

Depth profiling of element concentration -interfaces structures- Ti on Si deposition by magnetron sputtering (buffer layer) analysis: -RBS spectrum shows an non uniform concentration of deposited Ti layer. For a good fit with simulated spectrum, was necessary to involve 4 sublayers of TiNO of app. 68nm thickness with different stoichiometry. -This result suggest the influence of residual gases inside deposition chamber which are combining with Ti ions from produced plasma.

New Fields and new possible experiments/applications at the 3 MeV tandetron

New possible experiments/applications at the 3 MV tandetron Channeling of ions into crystalline structures is a powerful tool to inspect the disorder in crystals as well as to find and locate the position of impurities in crystals. Also, in crystalline heavy matrices, channeling technique allow the measurement of light elements (C, O, N) impurities Complex simultaneously/successive IBA methods aiming a better characterization of a large class of samples (RBS, PIXE, PIGE, NRA, HIRBS). Microbeam scanning of surface micro-structured samples:

New possible experiments/applications at the 3.5MeV tandetron Studies of beams scattering at large grazing angles on amorphous and crystalline samples (studies of phenomenon which occur in focusing effect of tapered glass capillaries and so called surface channeling of ions). In this way it is possible to obtain in a simple way nano-beams for analytical applications. The existing beam line dedicated for implantation of ions in solid open exciting ways for collaborative R&D applications: - nanocavities layers induced by different ions ions implanted in semiconductors acting as getter for metallic impurities and silicon nanocrystals embedded in silicon dioxide which exhibit a strong room temperature luminiscence XTEM images showing the microstructure and disorder around bubbles and nanocavities in Si following 100 keV H implantation to a dose of 3x1016 cm-2 and annealing to a) 500 o C and b) 750 o C. a) RBS Au profiles both as-implanted and after 850oC annealing for an 8x1014 Au cm-2 implant into Si that has a cavity band at a depth of 1μm. b) An XTEM micrograph of the cavity band region after annealing.

Ion irradiation for cell surgery with glass capillary Y. Iwai et al., Appl. Phys. Lett (2008).

Strengths and Advantages Very good parameters of the accelerated beams (energy stability and resolution, micro beam facility), easy handling (computer controlled of the accelerator and beam transport) Possible use of simultaneous methods (RBS, PIXE, NRA, PIGE) Large number of ion species being accelerated Dedicated beam line for complex Ion Beam Analysis Dedicated beam line for ion implantation Existing experience in IBA applications at IFIN-HH Important national/international teams involved in material sciences can have benefits of this R&D infrastructure for IBA as a powerful tool for more complete characterization of sample as composition and structure

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