BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Application of SR methods for the study of nanocomposite materials for Hydrogen Energy. DTSTART;VALUE=DATE-TIME:20160707T032000Z DTEND;VALUE=DATE-TIME:20160707T034000Z DTSTAMP;VALUE=DATE-TIME:20260307T234535Z UID:indico-contribution-136-1193@indico.inp.nsk.su DESCRIPTION:Speakers: V.A. Sadykov (Boreskov Institute of Catalysis of SB RAS\, Novosibirsk\, Russia)\nApplication of SR methods for the study of na nocomposite materials for Hydrogen Energy.\nS.N. Pavlova\, V.V. Kriventsov \, Z.S. Vinokurov\, N.F. Eremeev\, V.A. Sadykov\nBoreskov Institute of Cat alysis of SB RAS\, Novosibirsk\, Russia\n\nIn the emerging field of Hydrog en Energy\, tailor-made design of the active components of monolithic cata lysts for selective oxidation/autothermal reforming of hydrocarbons into syngas at short contact times\, water gas shift reaction and preferential oxidation of CO in the hydrogen ex-cess is also based upon the concept of the bifunctional reaction mechanism\, in which oxygen mobil-ity in comple x oxide fluorite-like support (doped ceria or ceria-zirconia) plays an imp ortant role. Complex oxide nanocomposites with perovskite-like and fluorit e-like structures are known as good ionic or mixed ionic-electronic conduc tors. This ensures their broad application in the rapidly de-veloping tech nologies based upon solid state ionic devices including fuel cells (as ele ctrolytes\, components of cathodes and anodes)\, catalytic membrane react ors for ultra-pure oxygen and syn-gas generation. Defect structure of the se complex oxide systems is considered as an important factor in ensuring their high performance. However\, this restricts ability of traditional st ructural techniques to elucidate atomic-scale details of their real struct ure responsible for the transport properties of these systems. This is the reason why Synchrotron Radiation studies (XANES\, EXAFS\, XRD) of the rea l/defect structure of complex oxide nanocomposites become tremendously imp ortant. This presentation summarizes results of these SR studies for such nanocomposite systems as ceria doped by Me\; ceria-zirconia doped by Ln an d PrNi0.5Co0.5O3 δ (PNC)\, Ce0.9Y0.1O2 δ (YDC)\, Ce0.65Pr0.25Y0.1O2 δ ( YPDC)\, CeO2 and Pr6O11 powders were synthesized by modified Pechini route . Complimentary methods such as HRTEM\, Raman\, UV-Vis\, XPS\, magnetic me asurements etc are applied as well to verify different hypothesis on the type of the real structure.\nAs follows from analysis data\, Ce cations ch arge was generally 4+ for PNC – YDC\, while Pr charge was commonly 3+ fo r PNC and both 3+ and 4+ for its nanocomposite. Since Pr charge var-ies di ffering from Ce\, it can be Pr which is generally responsible for oxygen v acancies formation observed. This is in agreement with data on oxygen mobi lity and surface reactivity studies being carried out previously. Pr and C e coordination numbers obtained from radial distribution functions are clo se to the ones in slightly distorted P and F structures. Ce LIII edge spec tra for nanocomposite is similar to YPDC with difference explained by loca l Pr:Ce ratio variation and structure distortion. Thus\, generally Pr3+ mi gration from P to F phase and its charge variation may cause additional va -cancies formation. This agrees with data obtained in the current work and previous studies. For nanocrystalline doped ceria-zirconia system\, the m ost important factor controlling the lattice oxygen mobility appears to be length of Ce-O (Zr-O) bond and distortion of respective coordination sphe res\, while free anion vacancies are less important if present at all. Ins tead\, the fast oxygen diffu-sion pathways could be associated with disord ered domain boundaries including those between do-mains of different chemi cal compositions. In this case\, the trend in variation of the real struct ure pa-rameters with the content and size of a doping cation is much more complex due to coexisting in the host fluorite-like lattice of small (Zr4+ ) and big (Ce4+) cations with different modes of the first coor-dination s phere distortion. Moreover\, this affects even the mode of the cations spa tial distribution in the lattice or in the surface layer. Thus\, doping of ceria-zirconia (1:1) solid solution by Ca or Gd re-sults in depletion of the surface layer by Zr. For these systems\, more symmetric coordination e nvi-ronment around Zr cations in doped samples suggests some ordering due to incorporation of a big doping cation\, which results in decreasing the lattice oxygen mobility. \nThe work was done using the infrastructure of t he Shared-Use Center “Siberian Synchrotron and Terahertz Radiation Cente r (SSTRC)” based on VEPP-3 of BINP SB RAS. This work was sup-ported by B IOGO FP7 Project\, Russian Academy of Sciences\, and Federal Agency of Sci entific Or-ganizations (project V.44.1.17).\n\nhttps://indico.inp.nsk.su/e vent/3/contributions/1193/ LOCATION:Budker INP Conference Hall URL:https://indico.inp.nsk.su/event/3/contributions/1193/ END:VEVENT BEGIN:VEVENT SUMMARY:Agilent Technologies solutions in vacuum equipment for high energy physics DTSTART;VALUE=DATE-TIME:20160707T034000Z DTEND;VALUE=DATE-TIME:20160707T040000Z DTSTAMP;VALUE=DATE-TIME:20260307T234535Z UID:indico-contribution-136-1194@indico.inp.nsk.su DESCRIPTION:Speakers: Mikhail Rukavishnikov (Scientific equipment group)\n https://indico.inp.nsk.su/event/3/contributions/1194/ LOCATION:Budker INP Conference Hall URL:https://indico.inp.nsk.su/event/3/contributions/1194/ END:VEVENT BEGIN:VEVENT SUMMARY:XAFS spectroscopy - a useful tool for determining structure parame ters and the electronic state of various nanosystems DTSTART;VALUE=DATE-TIME:20160707T042000Z DTEND;VALUE=DATE-TIME:20160707T044000Z DTSTAMP;VALUE=DATE-TIME:20260307T234535Z UID:indico-contribution-136-1196@indico.inp.nsk.su DESCRIPTION:Speakers: Simon Erenburg (Nikolaev Institute of Inorganic Chem istry SB RAS\, Budker Institute of Nuclear Physics SB RAS)\nSome of the EX AFS spectra above Ga*K*-and Ge*K*- edges were measured at the VEPP-3 stora ge ring (beamline 8) of Siberian Synchrotron and Terahertz Radiation Cente r (SSTRC) of the Budker Institute of Nuclear Physics (BINP SB RAS\, Novosi birsk\, Russia). Other part of the spectra was measured at the ESRF (Greno ble\, France). The high energy resolution fluorescence detected HERFD-XANE S and EXAFS experiments have been performed at 12K at the beamline ID26 or ID20 equipped by 5-analyzer x-ray emission spectrometer.\n\n**1. Electron ic and spatial structure of "calibrated" gold clusters in the cavities of cucurbit[*6\, 7*] uril molecules.**\n\nThe Au*L$_{III}$* X-ray absorption fine structure (XAFS) spectra have been measured for samples containing ca librated gold nanoparticles *D* ≤ 1nm nm in cavities of cucurbituril mol ecules (CB[*6\, 7*]). It has been found that gold clusters are characteriz ed by smaller 0.03 Å interatomic distances and a considerable reduction i n the Au-Au coordination numbers (*N* ≤ 8) as compared with bulk gold. N o visible shifts of Au*L$_{III}$* absorption edges (±0.02 eV) and differe nces in the Au charge state for Au@СВ[*6\, 7*] samples containing small Au clusters were detected in comparison with bulk Au metal. A threefold an d more increase in the Debye-Waller factor at 12K was found for the nanopa rticles in comparison with bulk metal and correspondingly\, a substantial increase in the structural disorder. It has been found that special chemic al (catalytic) and physical (optical) properties of small gold particles a re likely to be attributed to this structure changes and the size effect w ith the appearance of a band gap between the occupied and unoccupied elect ronic states\, rather than changes in the charge state of gold clusters an d presence of strongly pronounced vertices and edges in structure of nanop articles.\n\n**2. Microstructure of multilayered heterosystems GaNAlN.**\n \nA minimal drop (~0.01 Å) in the interatomic Ga–Ga distances *R*(Ga) r elative to a thick solid film was obtained from the analysis of GaK EXAFS spectra for multilayered GaN/AlN samples with "thick" (550–850 nm) super lattices\, agreeing with the numerous dislocations found in them and the c orresponding stress relaxation in the GaN layers. The interatomic Ga–Ga distances *R*(Ga) for samples with fewer layers and "thin" (80–150 nm) s uperlattices fell more substantially (by $\\sim{0.03}$ Å)\, corresponding to the more substantial deformations and stresses indicated by our earlie r results for GaN quantum dots in a AlN host. The influence of the growth conditions and the thickness of the superlattices on mixing in the near b oundary layers and the optical properties of the GaN/AlN superlattices wer e revealed. It was established that Ga–Al mixing occurs only in the laye r nearest to the interface. Anomalously long Ga–Al distances ($\\sim{3.2 5}$ Å) were observed for samples with thick superlattices. This effect ca n be explained by a nonequilibrium transition from GaN growth to AlN growt h and the more substantial stresses at the interface of such superlattices .\n\n**3. Structural characteristics of K-Bi citrate (De-Nol) and its clus ters in aqueous solutions.**\n\nBi*L$_{III}$* EXAFS spectra of an amorphou s solid Bi complex with citrate (De-Nol) and its aqueous solutions in a wi de concentration range are measured. For the solutions good agreement is r evealed between their structural parameters and the averaged interatomic d istances and coordination numbers of 12-nuclear Bi clusters. So\, it is fo und that droplets of the colloidal solution have a structure close to the solid $Bi_{12}O_{22}$ cluster structure. When the concentrated solution is diluted the cluster structure is somewhat modified\, it remaining similar to the structure of the $Bi_{12}O_{22}$ cluster and even at a tenfold dil ution and the nearest (oxygen) spheres of the Bi environment changing insi gnificantly.\n\nThis work was supported by the Russian Foundation for Basi c Research (project no. 16-02-00175a)\n\nhttps://indico.inp.nsk.su/event/3 /contributions/1196/ LOCATION:Budker INP Conference Hall URL:https://indico.inp.nsk.su/event/3/contributions/1196/ END:VEVENT BEGIN:VEVENT SUMMARY:Synchrotron-based experimental study and theoretical simulation of hydrogen desorption for solid-state hydrogen storage material – Mn(BH4) 2 DTSTART;VALUE=DATE-TIME:20160707T052000Z DTEND;VALUE=DATE-TIME:20160707T054000Z DTSTAMP;VALUE=DATE-TIME:20260307T234535Z UID:indico-contribution-136-1205@indico.inp.nsk.su DESCRIPTION:Speakers: Ilia Pankin (Southern Federal University\, IRC "Smar t materials")\nThe material under study is manganese borohydride Mn(BH4)2. The unique thermodynamics and kinetic properties in combination with high volumetric and gravimetric hydrogen densities make this compound a very p romising candidate to solid state hydrogen storage. Local atomic structure of Mn(BH4)2 upon heating was completely studied by in-situ temperature-de pendent measurements of X-ray powder diffraction patterns and Mn K-edge XA NES (X-ray Absorption Near Edge Structure) at SNBL-01b beamline of ERSF. D iffraction patterns indicate amorphisation during heating the sample above 110 oC. XANES Mn K-edge spectra also undergo significant changes at the t emperature from 120 oC to 160o C. TGA analysis reveals drastic weight redu ction (up to 10 mas %) of Mn(BH4)2 at the same temperature range. It was c oncluded that temperature induced phase transition which is accompanied by sample amorphisation process as well as abundant hydrogen release were ob served.\n We have performed ab-inito structure prediction using pseudo potential approaches within DFT approximation (VASP 5.3 code). Structural models with different contents of hydrogen atoms per unit cell were consid ered. Cell shape\, cell volume and atomic position were relaxed. The simul ation indicates collapse of porous structure and decrease in the interatom ic distances Mn-B and Mn-Mn provided by significant reduction of cell volu me. To find possible stable structures of dense Mn-B phase we have applied evolutionary algorithms as implemented in the USPEX code. Several low-ene rgy candidates were selected for further analysis. Owing to amorphisation process we expect that the sample after heating has unhomogeneous structur e with a nanodomain features corresponding to various crystalline atomic o rdering. XANES Mn K-edge spectra were calculated for the lowest energy str uctural models\, predicted by means of simulations. Numerical analysis of the discrepancy between experimental and theoretical XANES spectra was per formed in order to verify the MnxBy local structure observed in the experi ment.\n\nhttps://indico.inp.nsk.su/event/3/contributions/1205/ LOCATION:Budker INP Conference Hall URL:https://indico.inp.nsk.su/event/3/contributions/1205/ END:VEVENT BEGIN:VEVENT SUMMARY:XAFS study of catalytic nanosystems promising for environmental ca talysis DTSTART;VALUE=DATE-TIME:20160707T044000Z DTEND;VALUE=DATE-TIME:20160707T050000Z DTSTAMP;VALUE=DATE-TIME:20260307T234535Z UID:indico-contribution-136-1244@indico.inp.nsk.su DESCRIPTION:Speakers: E.P. Yakimchuk (Boreskov Institute of Catalysis of S B RAS\, Novosibirsk\, Russia)\nRecently\, low-content supported mono- and bimetallic catalytic nanosystems containing transient and noble metals ins pire great interest in researchers\, because of their practical applicatio n for a wide range of processes of environmental catalysis owing to the po ssibility of varying catalytic properties\, relatively low cost of the fin al products\, and ease of recovery of expensive components of the exhauste d catalysts. The samples of modeljed catalysts ~1% (Pt\, PtCo\, Pd\, PdCo \, PdMn and others) were obtained by varying preparation methods of active component (deposition-precipitation\, zol-gel\, ion exchange\, MOCVD ) fr om mono- and heterometallic precursors of different nature. Nanoparticles of active component were located on various supports (C\, SiO2\, Al2O3\, TiO2\, ZrO2) and different activation and reduction conditions were used. All XAFS spectra of the studied samples were recorded at the Siberian Sync hrotron and Terahertz Radiation Center (SSTRC\, Novosibirsk). Genesis of the state and local structure arrangement of supported metal nanoparticles of the studied catalytic nanosystems were characterized in detail. Correl ations between their catalytic properties\, local structure distortions an d state of metal components were demonstrated. The interatomic distances a nd corresponded coordination numbers were calculated by fitting. All possi ble structural models were discussed. Additionally\, morphology and compos ition of the samples of catalysts were studied by the TEM\, EDX and XPS me thods . The data obtained by all the methods are in a good agreement. \n\n The work was done using the infrastructure of the Shared-Use Center “Sib erian Synchrotron and Terahertz Radiation Center (SSTRC)” based on VEPP- 3 of BINP SB RAS. This work was supported by RFBR (140301066\, 163350248\, 163350249\, 163350250\, 160301139)\, SB RAS comprehensive program II.2P ( Project 0305-2015-0018).\n\nhttps://indico.inp.nsk.su/event/3/contribution s/1244/ LOCATION:Budker INP Conference Hall URL:https://indico.inp.nsk.su/event/3/contributions/1244/ END:VEVENT BEGIN:VEVENT SUMMARY:Near-surface regions of chalcopyrite studied using XPS\, HAXPES\, XANES and DFT DTSTART;VALUE=DATE-TIME:20160707T050000Z DTEND;VALUE=DATE-TIME:20160707T052000Z DTSTAMP;VALUE=DATE-TIME:20260307T234535Z UID:indico-contribution-136-1246@indico.inp.nsk.su DESCRIPTION:Speakers: Yuri Mikhlin (Institute of Chemistry and Chemical Te chnology of the Siberian Branch of the Russian Academy of sciences)\nChalc opyrite CuFeS2\, is the most common mineral of copper\; chalcopyrite and r elated compounds are of interest for thermoelectric\, photovoltaic and oth er applications. We also examined valleriite (Fe\,Cu)S(Mg\,Al)(OH)2\, natu ral nanocomposite composed of chalcopyrite-like Fe\,Cu sulfide layers and brucite-like oxide layers\, which is important mineral of Norilsk ore depo sits. Conventional XPS and synchrotron-based hard photoemission spectrosco py (HAXPES)\, surface-sensitive Cu L-\, Fe L-\, S L-edge TEY XANES and S K -\, Fe K-edge TEY and PFY XANES spectroscopy were used along with some oth er experimental techniques and DFT+U calculations in order to characterize near-surface regions of the initial (in fact\, oxidized in air) minerals and the ones chemically oxidized in Fe(III) solutions. The synchrotron irr adiation experiments were performed at Russian-German laboratory and HIKE endstations at BESSY II facility (Helmholtz Zentrum Berlin). Both the elem ent concentrations and the chemical state of atoms\, e.g.\, mono-\, di-\, polysulfide and other S species\, as a function of the probing depth and t he reaction conditions\, were studied. The near-surface regions of chalcop yrite are generally consist of (i) a thin\, no more than 1-4 nm\, strongly metal-depleted outer layer containing polysulfide species\, (ii) a layer with smaller stoichiometry deviations and low\, if any\, concentrations of polysulfide\, which composition and dimensions strongly depend on the che mical treatment conditions\, and (iii) an about stoichiometric underlayer extended to at least several dozen of nanometers. The latter shows Fe K-ed ge TEY spectra altered probably due to a high content of defects\, even if only oxidized in ambient air. In contrast to other spectra\, Cu L-XANES p atterns were surprisingly insensitive to the changes of the composition of the reacted near-surface layers. DFT+U analysis of the iron-deficient str uctures formed shows that polysulfide species are stable only near the sur face\, copper remains 4-fold coordinated to S in the layers with disulfide anions\, the layer with iron deficiency transforms from antiferromagnetic and semiconducting state into paramagnetic metallic state. Moreover\, the formation of these structures is generally energy-favorable under the oxi dative conditions. The lengthy regions are expected to heavily affect the electronic characteristics and processes involving surface and interfacial charge transfer.\n\nhttps://indico.inp.nsk.su/event/3/contributions/1246/ LOCATION:Budker INP Conference Hall URL:https://indico.inp.nsk.su/event/3/contributions/1246/ END:VEVENT BEGIN:VEVENT SUMMARY:Current status of EXAFS station of SSTRC. Application of XAFS spec troscopy for the study of promising functional nanomaterials. DTSTART;VALUE=DATE-TIME:20160707T030000Z DTEND;VALUE=DATE-TIME:20160707T032000Z DTSTAMP;VALUE=DATE-TIME:20260307T234535Z UID:indico-contribution-136-1247@indico.inp.nsk.su DESCRIPTION:Speakers: Vladimir Kriventsov (Boreskov Institute of Catalysis )\nNowadays the method of XAFS spectroscopy in a different methodical opti ons using of SR sources is a recognized powerful tool to study the state o f the elements and the local structure for the various nanosystems having different aggregation: alloys\, high dispersed material\, semiconductors\, solutions\, glasses and others. \nIn this report\, by the example of work s performed at the EXAFS station of SSTRC\, for a variety of nanosized sys tems used in catalysis\, materials science\, biology\, demonstrated the po ssibility of XAFS spectroscopy\, as an independent method and in combinati on with other physical methods of research - HRTEM\, XRD\, XPS\, SEM. The prospects of an integrated approach to study of nanostructured systems: di lute encapsulated ordered semiconductor nanostructures\, nanocomposite cat alysts having complex composition\, biological nanomaterials and others ar e shown.\nThe work was done using the infrastructure of the Shared-Use Cen ter “Siberian Synchrotron and Terahertz Radiation Center (SSTRC)” base d on VEPP-3 of BINP SB RAS. This work was supported by Russian Academy of Sciences and Federal Agency of Scientific Organizations\, SB RAS comprehen sive program II.2P (Project 0305-2015-0018)\, RFBR (140301066\, 160301139) .\n\nhttps://indico.inp.nsk.su/event/3/contributions/1247/ LOCATION:Budker INP Conference Hall URL:https://indico.inp.nsk.su/event/3/contributions/1247/ END:VEVENT BEGIN:VEVENT SUMMARY:Probing magnetic sublattices in multiferroic Nd0.5Ho0.5Fe3(BO3)4 s ingle crystal via hard x-ray magnetic circular dichroism DTSTART;VALUE=DATE-TIME:20160707T054000Z DTEND;VALUE=DATE-TIME:20160707T060000Z DTSTAMP;VALUE=DATE-TIME:20260307T234535Z UID:indico-contribution-136-1307@indico.inp.nsk.su DESCRIPTION:Speakers: Mikhail Platunov (Kirensky Institute of Physics)\nWe present an element-specific magnetizations study of the multiferroic Nd0. 5Ho0.5Fe3(BO3)4 single crystal. Our experimental results confirm the coexi stence of three magnetic subsystems (Fe\, Ho\, and Nd). It was found that the Ho magnetic moment undergoes the pronounced spin-reorientation transit ion. At the magnetic ield (less than 1 T) the Ho and Nd magnetization curv es demonstrate different of the slopes indicating different strength of f- d exchange interactions with iron subsystem. It was shown that the Fe magn etic moment behave like a weak ferromagnet\, but not antiferromagnetically . These magnetic findings are relevant to understand magnetism of Nd0.5Ho0 .5Fe3(BO3)4 single crystal and other multiferroic ferroborates.\n\nThis st udy was supported in part by the grants of the Council for Grants of the P resident of the Russian Federation (SP-938.2015.5\, NSh-7559.2016.2)\, the Russian Foundation for Basic Research (project nos. 16-32-60049 mol_a_dk\ , 16-32-00206 mol_a). The work of first author (M.P.) was supported by the grant of KSAI ‘‘Krasnoyarsk Regional Fund of Supporting Scientific an d Technological Activities’’ and by the program of Foundation for prom oting the development of small enterprises in scientific and technical sph ere (“UMNIK” program).\n\nhttps://indico.inp.nsk.su/event/3/contributi ons/1307/ LOCATION:Budker INP Conference Hall URL:https://indico.inp.nsk.su/event/3/contributions/1307/ END:VEVENT END:VCALENDAR