1 / 18

Study of magnetic properties of a new vanadate Cu 13 Fe 4 V 10 O 44

Study of magnetic properties of a new vanadate Cu 13 Fe 4 V 10 O 44. Janusz Typek Institut e of Physics, West Pomeranian University of Technology , Szczecin, Poland. Outline. Why new vanadate Cu 13 Fe 4 V 10 O 44 Sample preparation and chemistry

claus
Download Presentation

Study of magnetic properties of a new vanadate Cu 13 Fe 4 V 10 O 44

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Study of magnetic properties of a new vanadate Cu13Fe4V10O44 Janusz Typek Institute of Physics, West Pomeranian University ofTechnology, Szczecin, Poland

  2. Outline • Why new vanadate Cu13Fe4V10O44 • Sample preparation and chemistry • Measuring methods: dc magnetometry and EPR • Results of dc magnetization measurements • Results of EPR measurements • Conclusions about magnetic structure

  3. Why to study Cu13Fe4V10O44 ? • Similar compounds from the same system of vanadates have important catalytic properties • Defect structure and grain surface play an important role in catalysis • Knowledge of magnetic defects and ions may lead to better understanding of the mechanism of the catalytic processes

  4. Sample preparation 13 CuO + 5 V2O5 + 2 Fe2O3 → Cu13Fe4V10O44 A. Blonska-Tabero, J. Therm. Anal. Calorim. 110 (2012) 161

  5. Structure – possible types Lyonsite, -Cu3Fe4(VO4)6, a new iron-copper vanadate mineral Howardewansite Mineral NaCuFe2(VO4)3 In figure Mn3Fe4(VO4)6 VO4, FeO6, MnO5, MnO4 polyhedra six isolated VO4 tetrahedra FeO6 octahedra square-planar CuO4 groups

  6. EPR and dc magnetometry Magnetic resonance spectrometer X-band, Bruker E 500 (1997) Magnetic Property Measurements System MPMS XL-7, Quantum Design (2011) Dynamics τ~10-10 s Static τ~1 s

  7. dc magnetization: susceptibilitystudy

  8. dc magnetization: reciprocal susceptibility

  9. dc magnetization: Curie-Weiss law Fe3+, 3d5, high-spin S=5/2, L=0, J=5/2, , for g=2 μ=5.9 μB

  10. dc magnetization: high-temperature range magnetic energy non-magnetic

  11. T [K] g J CH [μB/f.u.·Oe] 2 1.15(2) 3.00(3)·10-5 5 2.01(3) 2.00(5)·10-5 200 9.655(6) 0 250 9.949(2) 0 dc magnetization in an external field Modified Langevin AFM clusters

  12. EPR: spectra and fitting Lorentzian lineshape Br - resonance field ΔB -linewidth Iint – integrated intensity

  13. EPR: g-factor

  14. EPR: linewidth

  15. EPR: linewidth vs. resonance field

  16. EPR: integrated intensity I0=5.373·1010, C2=1.13·1012, TCW=-60.2 K. AFM clusters

  17. General picture of the magnetic state of Cu13Fe4V10O44

  18. THE END Thank you!

More Related