SVIBOR - Project code: 1-03-022

MINISTRY OF SCIENCE AND TECHNOLOGY

Strossmayerov trg 4, HR - 10000 ZAGREB
tel.: +385 1 459 44 44, fax: +385 1 459 44 69
E-mail: ured@znanost.hr

SVIBOR

SVIBOR - Collecting Data on Projects in Croatia

Project code: 1-03-022


MICROSTRUCTURAL INVESTIGATION OF NOVEL MATERIALS


Main researcher: BONEFAČIĆ, ANTUN (4471)


Assistants
Type of research: basic
Duration from: 01/01/91. to 12/15/96.
Papers on project (total): 144
Papers on project quoted in Current Contents: 66
Institution name: Prirodoslovno-matematički fakultet, Prirodoslovni odjeli, Zagreb (119)
Department/Institute: Department of Physics
Address: Bijenička cesta 32,p.p.162
City: 10000 - Zagreb, Croatia
Communication
Fax: 385 (0)41-432-525
Phone: 385 (0)01-4555730
E-mail: atonejc@phy.hr
Summary: In the past period we have continued our work on structural investigation of alloys and kinetics of their phase transformation. In a systematic investigation of mixed metal oxides, the systems Fe2O3-M2O3, M=Nd,Sm,Al,Ga,In,Gd,Eu, Al2O3-Cr2O3, Fe2O3-SnO2 i Fe2O3-NiO in the whole concentration range. By accurate measurement of the lattice constants of the Al-rich matrix and precipitates, valuable information on the elemental composition of particular phases in Al-Zn and Al-Zn-Mg systems have been obtained. We have continued our work on preparation and examination of ball-milled materials. Ball milling was applied on zeolites and on various phases of alumina and zirconia. This research is closely related to wide range of applications. A method to analyze powder-diffraction line broadening was proposed and applied to some novel high-temperature superconductors. The analysis of X-ray diffraction peak shifts in the aluminium+mullite+alpha-alumina composites showed that Al matrix stays in tension. Stresses increase with both increasing particle size and volume fraction of composites. In order to study the high-temperature superconductors, the modifications of crystal structure due to aliovalent ion substitutions and suitable oxygen stoichiometry control were studied. We have also continued our investigations of polymorfic transformation in Sn supported clusters. The distribution of grain sizes of the YBa2Cu3O7-x high temperature superconducting compound was investigated. The distributions are fitted best with Gauss grain size distribution. This is consistent with the fact that critical current densities in ceramic HTSC samples are limited by the quality of the inter-grain boundaries. Processes of precipitation in water solutions and corrosion of steels in media of different chemical pproperties were also studied. We also performed differential scanning calorimetry, thermogravimetry and structural analysis of nanocrystalline FECuNbSiB alloys.

Keywords: X-ray diffraction, electron diffraction, TEM, HREM, EDS, Moessbauer spectroscopy, lattice parameters, nanocrystalline materials, superconductivity, metastable phases, kinetics of phase transformation, diffraction line broadening, profile fitting, phase transitions, phase diagrams, intermetallic compounds, metallic alloys, metallic oxides, solid solutions.

Research goals: Although metallic and semiconducting alloys as well as superconducting ceramics are intensively studied, in these areas exist wide possibilities of investigation. The aim of our work was to obtain new insights on microstructure and structure-related physical properties of the quoted materials. New results are obtained in the investigation of metal oxides, aluminium-based alloys, milled samples of zeolites and different samples of alumina and zirconia, evaporated Sn-clusters, as well in the domain of high-temperature superconductors. The results are given in the DESCRIPTION OF THE PROJECT and in the SUMMARY of this report.

COOPERATION - PROJECTS


  1. Name of project: NIST PN 978 Microstructure of Metastable Alloys
    Name of institution: National Institute of Standards and Technology, Materials Reliability Division
    City: 80303 - Boulder, Colorado, U.S.A.

  2. Name of project: JF 106 Microstructure-property relationships in metallic alloys and compounds
    Name of institution: National Institute of Science and Technology
    City: 80303 - Boulder, Colorado, U.S.A.

COOPERATION - INSTITUTIONS


  1. Name of institution: National Institute of Standards and Technology
    Type of institution: State institute
    Type of cooperation: Joint project
    City: 80303 - Boulder, Colorado, U.S.A.

  2. Name of institution: Institut "Ruđer Bošković"
    Type of institution: State institute
    Type of cooperation: Joint publishing of scientific papers
    City: 10000 - Zagreb, Croatia

  3. Name of institution: Institut za fiziku u Zagrebu
    Type of institution: State institute
    Type of cooperation: Joint publishing of scientific papers
    City: 10000 - Zagreb, Croatia

  4. Name of institution: Metalurški fakultet u Sisku
    Type of institution: Economical/Production
    Type of cooperation: Joint publishing of scientific papers
    City: 44000 - Sisak, Croatia

  5. Name of institution: Departament de Fisica, Universitat Autonoma de Barcelona
    Type of institution: University/Faculty
    Type of cooperation: Joint publishing of scientific papers
    City: Barcelona, španjolska

  6. Name of institution: Department of Structural Chemistry, Stockholm University
    Type of institution: University/Faculty
    Type of cooperation: Joint publishing of scientific papers
    City: Stockholm, švedska

  7. Name of institution: Electron Microscopy for Materials Research, Universiteit Antwerpen (RUCA)
    Type of institution: University/Faculty
    Type of cooperation: Joint publishing of scientific papers
    City: Antwerpen, Belgija
Other information about the project.
MZT Croatian language SVIBOR Alphabetic list Sorted on project code Sorted on institutions Search help
Ministry of
Science and
Technology		 Croatian
language		 Svibor
homepage		 Alphabetic
list		 Sorted on
project code		 Sorted on
institutions		 Search Help
Last update: 10/10/95
Information: svibor@znanost.hr