Exchange bias, training effect, and bimodal distribution of blocking temperatures in electrodeposited core-shell nanotubes

2013 ◽  
Vol 87 (13) ◽  
Author(s):  
M. P. Proenca ◽  
J. Ventura ◽  
C. T. Sousa ◽  
M. Vazquez ◽  
J. P. Araujo
Keyword(s):  
Exchange Bias ◽  
Bimodal Distribution ◽  
Training Effect ◽  
Core Shell

scholarly journals Exchange-bias and magnetic anisotropy fields in core–shell ferrite nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
F. G. Silva ◽  
J. Depeyrot ◽  
Yu. L. Raikher ◽  
V. I. Stepanov ◽  
I. S. Poperechny ◽  
...  
Keyword(s):  
Spin Glass ◽  
Magnetic Moment ◽  
Exchange Bias ◽  
Uniaxial Anisotropy ◽  
Thermal Fluctuations ◽  
High Amplitude ◽  
Spin Coupling ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

AbstractExchange bias properties of MnFe$$_2$$ 2 O$$_4$$ 4 @$$\gamma$$ γ –Fe$$_2$$ 2 O$$_3$$ 3 core–shell nanoparticles are investigated. The measured field and temperature dependencies of the magnetization point out a well-ordered ferrimagnetic core surrounded by a layer with spin glass-like arrangement. Quasi-static SQUID magnetization measurements are presented along with high-amplitude pulse ones and are cross-analyzed by comparison against ferromagnetic resonance experiments at 9 GHz. These measurements allow one to discern three types of magnetic anisotropies affecting the dynamics of the magnetic moment of the well-ordered ferrimagnetic NP’s core viz. the easy-axis (uniaxial) anisotropy, the unidirectional exchange-bias anisotropy and the rotatable anisotropy. The uniaxial anisotropy originates from the structural core–shell interface. The unidirectional exchange-bias anisotropy is associated with the spin-coupling at the ferrimagnetic/spin glass-like interface; it is observable only at low temperatures after a field-cooling process. The rotatable anisotropy is caused by partially-pinned spins at the core/shell interface; it manifests itself as an intrinsic field always parallel to the external applied magnetic field. The whole set of experimental results is interpreted in the framework of superparamagnetic theory, i.e., essentially taking into account the effect of thermal fluctuations on the magnetic moment of the particle core. In particular, it is found that the rotatable anisotropy of our system is of a uniaxial type.

scholarly journals Exchange Bias Phenomenology and Models of Core/Shell Nanoparticles

ChemInform ◽  
2007 ◽  
Vol 38 (8) ◽  
Author(s):  
Oscar Iglesias ◽  
Amilcar Labarta ◽  
Xavier Batlle
Keyword(s):  
Exchange Bias ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

scholarly journals Shape-dependent exchange bias effect in magnetic nanoparticles with core-shell morphology

2015 ◽  
Vol 92 (6) ◽  
Author(s):  
V. Dimitriadis ◽  
D. Kechrakos ◽  
O. Chubykalo-Fesenko ◽  
V. Tsiantos
Keyword(s):  
Magnetic Nanoparticles ◽  
Exchange Bias ◽  
Shell Morphology ◽  
Core Shell ◽  
Bias Effect ◽  
Exchange Bias Effect

Giant exchange bias behavior and training effect in spin-glass-like NiCr2O4/NiO ceramics

2015 ◽  
Vol 50 (17) ◽  
pp. 5904-5911 ◽  
Author(s):  
L. G. Wang ◽  
C. M. Zhu ◽  
D. L. G. C. Bao ◽  
Z. M. Tian ◽  
S. L. Yuan
Keyword(s):  
Spin Glass ◽  
Exchange Bias ◽  
Training Effect ◽  
And Training
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