1. Level (Type) of work:
Qualifying graduate thesis/Master thesis.
2. Topic:
Study of crystal and magnetic structure of multiferroic compound BiMnO3 at high pressures.
3. Work objective:
Study of changes in crystal and magnetic structure of BiMnO3 by neutron and X-ray (synchrotron) radiation diffraction techniques, determination of structural parameters, magnetic moment, obtaining of pressure dependences of lattice parameters, valence bonds and angles, construction of Р-Т phase diagram. Analysis of interrelation of structural changes and changes in the character of magnetic ordering.
4. Short description:
A number of compounds with the general formula RMnO3 (R = Tb, Bi, Y, etc.) are multiferroics in which magnetic and ferroelectric ordering coexists. The compound BiMnO3 has a perovskyte-like crystal structure and is one of the most actively studied multiferroics at a normal pressure. At temperatures below Тс = 500 K this compound shows ferroelectric properties and at temperatures below 100 K ferromagnetic ordering is observed in this compound. Experiments on magnetic susceptibility at high pressures point to a magnetic phase transition at pressures P~1 GPa in BiMnO3. For detailed research of changes in the crystal and magnetic structure of BiMnO3 at high pressures it is planned to carry out neutron and X-ray diffraction experiments.
5. Basic facilities and software
Neutron diffractometer G6.1 (LLB, Saclay, France), X-ray energy-dispersive diffractometer F2.1 (DESY, Hamburg, Germany), diffractometer at the experimental station "Mediana" (RRC "KI", Moscow, Russia)
6. Results:
Preparation of publications and reports to conferences on the basis of the obtained results.
Defense of Diploma thesis.
7. Minimum required time: 1 year
8. Supervisors:
Denis Petrovich Kozlenko
Doctor of Phys. and Math. Sciences
9. Contact phone number and e-mail:
This email address is being protected from spambots. You need JavaScript enabled to view it., tel. (49621) 63783