STSM reports 3 year

Nini Pryds

Home Institution: University of Bialystok (Poland)

Host Institution: Free University of Berlin (Germany)

STSM period: 15.11.2015/21.11.2015

Brief Summary of the STSM activity:

During STSM, I have learned how to prepare stable solutions of pure magnetite and core-shell nanoparticles with additive cobalt-oxide shell. The main goal of my visit was to find the ratio between solvent and surfactant, in order to obtain stable ferrofluid, in which magnetic interaction between spices are in balance with electrostatic repulsion of surfactant. To do so, I have also learned how to exchange surface termination from organic to inorganic phase. In the end, all types of prepared nanoparticles were imaged by TEM.

Impact: strengthening of collaboartaion between Home and Host institutions and opening a new
possibility to start cooperation with the Host in other fields. The work is in progress and no results were publicated or presented in conference yet.

Alice Galdi

Home Institution:DIEM Università degli Studi di Salerno

Host Institution: GREYC ENSICAEN

STSM period: 17/11/2016 – 11/12/2016

Brief Summary of STSM activity:

We optimized a lithographic process in order to characterize the transport of SrMnO3/La0.7Sr0.3MnO3/SrMnO3 trilayer samples via current perpendicular-to-plane measurements. In order to fully understand the measurements, we also patterned twin samples for in-plane transport measurements, with special attention to electrical contacts allowing low contact resistance and noise. The measurements, to be performed at different temperatures, will allow to characterize the transport across the interfaces and the presence of localized states. Each trilayer was grown simultaneously on SrTiO3 substrate and Nb:SrTiO3 conducting substrate (for CPP measurements). The test measurements on CPP structures at room temperature reveal that the Nb:SrTiO3 / SrMnO3 junction has rectifying properties. The same behavior is observed in CPP measurements of trilayers.

Impact: The collaboration about nanostructured manganite multilayer between the home and host laboratory will continue with further work finalized to scientific publications.

Nuno Ferreira

Home Institution: i3N, Physics Department, Aveiro University (Portugal)

Host Institution: Salerno University (Italy)

STSM period: 30 Jan – 10 Feb 2018

Brief Summary of the STSM activity:

The aim of this mission was promote a future collaboration between these institutions (home and host), through different crystal growth techniques and characterization techniques. The idea was grow by optical floating zone SrTiO3 and CaMnO3 base systems for thermoelectric applications. The preparation of rods for techniques of crystal growth was also different: one uses isostatic pressure (host), while in home institute used a cold extrusion. In overall, the result of this mission was the knowledge transmitted and the contact for future work in crystal growth and characterization techniques base in thermoelectric applications.

Impact: New collaborations in material characterization and partners in a national application for R&D funding, in order to promote a deep collaboration. I’m grateful for this opportunity promote by this cost action.

Emiliano Di Gennaro

Home Institution:Università di Napoli Federico II, Napoli , Italy

Host Institution: Swiss Light Source Paul Scherrer Institut, Switzerland

STSM period: 2016-10-22 to 2016-10-28

Brief Summary of STSM activity:

The goal of the collaboration was to determine the nature of the interface states near the Fermi surface of LAO/ETO/STO and ETO/STO heterostructures and the Eu-4f, and in case Eu-5d states contribution to the conduction band of the spin-polarized 2DEG. With this aim, we fabricated ETO films in with different thicknesses on STO substrates at SIS beamline, by RHEED assisted PLD; then, we performed, in-situ, ARPES measurements at the HRPES station and spin-resolved ARPES at the COPHEE station. Instead to investigate the band structure and the orbital character of the electronically reconstructed LaAlO3/EuTiO3/SrTiO3 heterostructure fabricated in Naples, we used resonant soft x-ray angle resolved photoemission spectroscopy.

Impact: Compared to STO and LAO/STO, ETO and LAO/ETO/STO are system much less studied. As a consequence, the results we obtained in these measurements runs are of great interest and surely innovative, deserving high level publications.
We foresee to quickly publish the results obtained by resonant soft x-rays ARPES, which allow a relatively more immediate analysis. A first publication will concerns the fundamental spectroscopic features that we measured, and their comparison with the well known features of STO. Then, possibly, a second important output can come from the polaronic character of the interface states, if confirmed.
The measurements at High Resolution ARPES beamline will complement this study, allowing a detailed description of the ETO bands and Fermi surface, on which there are currently not a full knowledge. Finally, a further publication could come from the spin-resolved ARPES data, if the related analysis will furnish a complete picture.

Dennis Christensen

Home Institution: Technical University of Denmark

Host Institution: Bar-Ilan University

STSM period: 25 Oct 2016 – 15 Dec 2016

Brief Summary of STSM activity:

When depositing γ-Al2O3 on SrTiO3 we obtain an interface with properties differing significantly from the observed in the parent oxides. Despite stoichiometric γ-Al2O3 and SrTiO3 are electrically insulating and non-magnetic, we interface between these oxides hosts both a high-mobility electron gas and magnetism. During my stay at Bar-Ilan University, we performed a series of temperature dependent scanning SQUID measurements on the γ-Al2O3/SrTiO3 heterostructure. They showed the presence of magnetization in the heterostsructures along with characteristic temperatures consistent with my magnetotransport measurements.

Impact: The data were presented at the MRS autumn meeting 2017 in Boston, at the ToBe fall meeting 2017 in Riga, at the High Tech Summit 2017 in Copenhagen, at the Fusion Conferences on Functional Oxide Thin Films for Advanced Energy and Information Technology 2017 in Rome and at seminars at various universities.

Lavinia-Petronela Curecheriu

Home Institution: Alexandru Ioan Cuza University, Iasi

Host Institution: ICMATE-CNR, Genoa

STSM period: 19.11 / 08.12.2016

Brief Summary of the STSM activity:

During the STSM two types of lead free ceramics, with different grain size, were investigated: single phase Ba0.85Ca0.15Zr0.90Ti0.10O3 (BCTZ) and Ba0.85Ca0.15Zr0.90Ti0.10O3 +CaTiO3 composite. The idea was to investigate the role of the grain size on the functional properties and compare the results with the prediction of FEM simulations. Accordingly, the ceramics (single phase and composites), were sintered at different temperatures in the range 1400-15500C for several times (from 0.2h to 24h).
For SEM observation the cross-sections of the ceramic samples were polished and, after washing, thermally etched below the sintering temperature. Thus, the grain size can be determined from the SEM images. For composites, as the two phases have a significantly different composition, the grains of the minor phase (CaTiO3) can be easily identified using the back-scatter electrons (BSE) mode. In both cases the average grain size was determined by line-intercept method on the SEM micrographs.

Impact:I will send an abstract to TO-BE Spring Meeting 2017 with data concerning functional properties of (Ba,Ca)(Zr,Ti)O3 ceramics with different grain size.
Also, we will prepare and send an abstract at 15th Conference and Exhibition of the European Ceramic Society, (ECerS 2017) that will be held in Budapest, June 2017.
In January, I submitted an application for a national project dedicate to young researcher team with title: ”Size dependent properties of lead free ceramics”. In this proposal, I mentioned the COST MP1308 collaboration and the collaborations with ICMATE-CNR and dr. V. Buscaglia.

Cristina Pascual Gonzalez

web report not yet submitted

Pablo Vales Castro

Home Institution: lnstitut Català de Nanociencia Nanotecnologia (ICN2)

Host Institution: Luxembourg lnstitute of Science and Technology (LIST)

STSM period: February 25th 2017 / March 10th 2017

Brief Summary of STSM activity:

The eleetroealoric effeet was direetly measured in antiferroelectric PbZrO3 (PZO) ceramics with a FLIR
X6580se infrared camera as a function of temperature, foeusing in the temperature range dose and through the Curie temperature (Te). Voltage pulses were applied using a Keithley 1100 sourcemeter. We eould
experimentally observe the transition from the anomalous (negative) electroealorie effect displayed by
antiferroelectric materials to a positive electroealoric effeet upon heating, once the intermediate
ferroelectric phase of PZO near the Curie point was entered. Conversely, we saw the transition from positive to negative EC effeet on cooling, where we also saw a streteh in the temperature range of the positive EC
effect. The maximum figure of merit I 6T I/ I 6E I obtained for the negative EC response was 0.0852 K cm kV·1 the largest obtained so far. Moreover, an electroealorie response with mueh faster dynamies appeared in the immediate vieinity of Te in a very narrow temperature range (2-3 K), suggesting that at this temperature
nanoregions can be polarized which, due to their small size, exchange heat mueh more rapidly with their
environment.

Impact: The TO-BE action allowed us to firmly stablish a collaborative relationship between LIST and ICN2. An article on the researched topic at the host institution {LIST) will be published shortly, as soon as we obtain fin al additional information on higher quality samples after another stay at LIST in May of this year for another 2 {two) weeks.

Daniel Diaz-Fernandez

Home Institution: Jozef Stefan Institute

Host Institution: Andrew and Erba Viterbi Department of Electrical Engineering in Technion, Haifa, Israel

STSM period: 18/02/2017 to 25/02/2016

Brief Summary of STSM activity:

Epitaxial, ultra-thin (3-5 nm) SrTiO3/Sr/Si (001), grown by PLD for the purpose of integrating other complex oxides into silicon technologies, were measured by XRD at the Department of Electrical Engineering of Technion (Haifa, Israel), in order to determine their out-of-lattice parameter and strain. 10 samples were grown, in which several parameters of the growth, such as the crystallization temperature, stages coverage, Sr buffer layer thickness and aging effects were tested. The Rigaku SmartLab diffractometer available at that department, which is equipped with a powerful 18 kW rotating anode and a Bede D3 high-precision goniometer, allows for the detection of ultra-thin coverages and the measurement of θ-2θ difractograms and rocking curves. θ-2θ curves in the region near the SrTiO3 (002) peak (∼ 46°, 1h 30 min for each sample) were recorded for 7 of the samples, and the out-of-plane lattice parameter and their thickness were determined for them.

Impact: The data gathered in these measurements led to the successful granting of beamtime at the BM25-SpLine beamline of the ESRF (Grenoble, France), where high-resolution XRR and reciprocal space mapping measurements around relevant SrTiO3 peaks will be taken, and information about the in and out-of-plane parameters, mosaicity and tensions will be gathered. The results of these measurements will be included in a paper already in preparation, and shared in multiple International conferences.

Krunoslav Juraic

Home Institution: Ruđer Bošković Institute

Host Institution: Materials Center Leoben Forschung GmbH (MCL), Austria

STSM period: 2017-01-30 to 2017-02-24

Brief Summary of STSM activity:

Barium titanate (BaTiO3) thin films were deposited by spray pyrolysis. Deposition parameters were optimized to obtain a homogenous and very thin film of BaTiO3 to be used in the next step for the decoration of aligned titania nanotube array thin films. Influence of deposition parameters (precursor content and concentration, substrate type and temperature, spraying flux and spraying duration) on BaTiO3 layer properties was tested. Finally, BaTiO3 was sprayed on aligned TiO2 nanotube thin film samples previously prepared by titania anodization.
During this STSM we got a better insight into spray pyrolysis parameters to obtain good quality BaTiO3 thin film for sensor application and new ideas how to upgrade spray pyrolysis setup.

Impact: Conference contribution:
K. Juraić, M. Deluca, R. Wimmer- Teubenbacher, Barium titanate thin films deposition by spray pyrolysis, 13th Multinational Congress on Microscopy, Rovinj Croatia, 2017.
Colaboration and project:
Austria-Croatia bilateral project: TiO2, ZnO and BaTiO3 nanostructures and nanolayers for gas- and humidity-sensing devices with improved functionalities, 2018.-2019.

José Silva

Home Institution: University of Minho, Portugal

Host Institution: University of Twente, The Netherlands

STSM period: 11/02/2017 – 06/03/2017

Brief Summary of the STSM activity:

During the STSM I had the possibility to deposit by pulsed laser deposition (PLD) and characterize the heterostructures consisting of lead free ferroelectric 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BCZT) and semiconductor (ZnO) bilayers. Therefore, the first part of the work consisted in depositing the heterostructures on Nb:SrTiO3 substrates and investigating, by in-situ RHEED, the crystalline nature and growth mechanisms of the layers.
The second part of the work consisted on the structural and morphological characterization of the deposited samples by XRD and AFM techniques, respectively.

Impact: The work done during my STSM has been presented as a poster contribution at the TO-BE Fall Meeting 2017 hold in Riga 11-13 September 2017.

Fabio Miletto Granozio

web report not yet submitted

Francesco Chiabrera

Home Institution: Catalonia institute for Energy Research (IREC)

Host Institution: Technical University of Denmark (DTU)

STSM period: 2017-01-19 to 2017-03-09

Brief Summary of STSM activity:

My STSM activity has been devoted to the design and the realization of a device cable of actively modifying the strain state of epitaxial thin films and to investigate its effect on oxygen ion conductivity. The ”strainer” has been designed and customized to stand high temperature measurements (up to 650ºC) and different environments. An in-plane strain of almost 0.1% has been successfully applied and confirmed by XRD results. The strainer has been tested on Yttria-stabilized Zirconia thin films deposited on different substrates by electrochemical impedance spectroscopy. The small dimensions and the flexibility of the produced device will allow its use for the characterization of the effect of strain on the high temperature functional properties of different metal transition oxides.

Sonja Jovanovic

Home Institution: Vinca Institute of Nuclear Sciences, Belgrade (RS)

Host Institution: Institute of Structure of Matter, National Research Council, Monterotondo RM (IT)

STSM period: 2017-03-01 to 2017-03-31

Brief Summary of the STSM activity:

The main scientific activity during the STSM was focused on magnetic characterization and on investigation the influence of magnetic structure on magnetic properties of zinc doped cobalt ferrite nanoparticles. In particular, hysteresis loops measurements were performed in both in zero-field-cooling and field-cooling conditions, at different temperatures in order to get the information on the macroscopic magnetic properties (coercive field, saturation and remanent magnetization) and eventually on interface exchange coupling between magnetically ordered core and disordered canted shell (SQUID). Performing magnetization measurements in different applied fields, as a function of temperature and time, spin dynamics was investigated. Remanent magnetization measurements (IRM, DCD, Henkel plot) and relaxation measurements (Activation volume) were used to study the interparticle interaction.

Impact: The obtained results are presented at the:

4th Conference of The Serbian Society for Ceramic Materials, June 14 – 16, 2017, Belgrade, Serbia – oral talk.

19th Annual Conference YUCOMAT 2017 in September 4-8, Herceg Novi, Montenegro – oral talk.
MP 1308 TO-BE COST Action Fall Meeting, September 11-13, 2017, Riga, Latvia – poster presentation.