Study of magnetic properties of a new vanadate Cu13Fe4V10O44

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Study of magnetic properties of a new vanadate
Cu13Fe4V10O44

• Janusz Typek
• Institute of Physics, West Pomeranian University
  of Technology, Szczecin, Poland

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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

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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

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Sample preparation
13 CuO 5 V2O5 2 Fe2O3 ? Cu13Fe4V10O44
A. Blonska-Tabero, J. Therm. Anal. Calorim. 110
(2012) 161
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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
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EPR and dc magnetometry
Magnetic resonance spectrometer X-band, Bruker E
500 (1997)
Magnetic Property Measurements System MPMS XL-7,
Quantum Design (2011)
Dynamics t10-10 s
Static t1 s
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dc magnetization susceptibility study
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dc magnetization reciprocal susceptibility
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dc magnetization Curie-Weiss law
Fe3, 3d5, high-spin S5/2, L0, J5/2,
, for g2 ? µ5.9 µB
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dc magnetization high-temperature range
magnetic
energy
non-magnetic
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dc magnetization in an external field
Modified Langevin
AFM clusters
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EPR spectra and fitting
Lorentzian lineshape
Br - resonance field ?B -linewidth
Iint integrated intensity
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EPR g-factor
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EPR linewidth
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EPR linewidth vs. resonance field
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EPR integrated intensity
I05.373?1010, C21.13?1012, TCW-60.2 K.
AFM clusters
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General picture of the magnetic state of
Cu13Fe4V10O44
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THE END Thank you!