Giant exchange bias induced via tuning interfacial spins in polycrystalline Fe3O4/CoO bilayers

2021 ◽  
Author(s):  
Fanghua Tian ◽  
Yebei Li ◽  
Qizhong Zhao ◽  
Kaiyan Cao ◽  
Dingchen Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Exchange Bias

A giant exchange bias of 9600 Oe was achieved under a magnetic field HFC = 20 kOe in Fe3O4/CoO films.

Magnetic field dependence of threshold electric field for magnetoelectric switching of exchange-bias polarity

2017 ◽  
Vol 122 (7) ◽  
pp. 073905 ◽  
Author(s):  
Thi Van Anh Nguyen ◽  
Yu Shiratsuchi ◽  
Atsushi Kobane ◽  
Saori Yoshida ◽  
Ryoichi Nakatani
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Field Dependence ◽  
Exchange Bias ◽  
Magnetic Field Dependence

Exchange Bias Induced in Polycrystalline Co/FeMn-Structures by Magnetic Field Cooling

2012 ◽  
Vol 190 ◽  
pp. 81-84
Author(s):  
N.G. Chechenin ◽  
I.O. Dzhun ◽  
S.A. Dushenko ◽  
E.A. Konstantinova
Keyword(s):  
Magnetic Field ◽  
Exchange Bias ◽  
Resonance Field ◽  
Bias Effect ◽  
Exchange Bias Effect ◽  
Annealing Temperatures ◽  
Layer Deposition ◽  
High Annealing ◽  
Thin Interlayer ◽  
Anneal Temperature

Using the method of angular dependence of ferromagnetic resonance field the magnetic properties of Si/SiO2/Cu/Co/FeMn/Cu and Si/SiO2/Cu/Co/Cu/FeMn/Cu structures were investigated. The layer deposition was carried out by magnetron sputtering in absence of an external magnetic field. It was established that thermal annealing with further cooling down in presence of a magnetic field can generate an exchange bias at anneal temperature significantly below the bulk antiferromagnetic Néel temperature. It was also shown that a thin interlayer between ferromagnetic and antiferromagnetic layers reduces the exchange bias effect at low anneal temperatures, however, makes this effect more stable at high annealing temperatures.

Soft X-ray Magnetic Circular Dichroism of a CoFe/MnIr Exchange Bias Film under Pulsed High Magnetic Field

2011 ◽  
Vol 4 (6) ◽  
pp. 066602 ◽  
Author(s):  
Tetsuya Nakamura ◽  
Yasuo Narumi ◽  
Toko Hirono ◽  
Misaki Hayashi ◽  
Kenji Kodama ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Circular Dichroism ◽  
High Magnetic Field ◽  
Exchange Bias ◽  
Magnetic Circular Dichroism ◽  
X Ray ◽  
Pulsed High Magnetic Field ◽  
Circular Dichroïsm

The Influnence of the Amplitude and Frequency of Sweeped Magnetic Field on the Exchange Bias and Coercivity for Ferromagnetic / Antiferromagnetic Films: Monte Carlo Simulation

2011 ◽  
Vol 694 ◽  
pp. 538-542
Author(s):  
Wen Ting Zheng ◽  
Li Qin Jiang ◽  
Zhi Gao Huang
Keyword(s):  
Magnetic Field ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Relaxation Time ◽  
Monte Carlo Method ◽  
External Magnetic Field ◽  
Low Temperature ◽  
Exchange Bias

The influnence of the amplitude (H0) and frequency of sweeped magnetic field on the exchange bias He and coercivity Hc for ferromagnetic/ antiferromagnetic films has been simulated with Monte Carlo method. In a cycle, the sweeped frequency is inversely proportional to Monte Carlo steps (MCSs). It is observed that, for smaller MCSs, the values of He and the blocking tempreture Tb reduce evidently with increasing MCSs; for larger MCSs, the values of He and Tb decrease gently with increasing MCSs. It is also found the values of He and Tb decrease obviously with increasing values of H0 (HN0). However, on the contrary, the value of Hc increases with increasing values of H0 (HN0). At low temperature and little HN0, the asymmetric loop may appear, which is attributed to the competition between the relaxation time and the period of the external magnetic field. Moreover, the symmetry of the loops influences evidently the values of He and Hc.

Exchange Bias in Co/FeMn and Co/IrMn Structures Induced by Deposition in Presence of Magnetic Field

2012 ◽  
Vol 190 ◽  
pp. 93-96
Author(s):  
I.O. Dzhun ◽  
N.G. Chechenin ◽  
S.A. Dushenko ◽  
E.A. Konstantinova
Keyword(s):  
Magnetic Field ◽  
Angular Dependence ◽  
Exchange Bias ◽  
Low Temperatures ◽  
Resonance Field ◽  
Blocking Temperature ◽  
Bilayer Structure ◽  
Magnetron Deposition ◽  
Unidirectional Anisotropy ◽  
Antiferromagnetic Layer

By measuring the angular dependence of ferromagnetic resonance field at room and low temperatures, it is demonstrated that the magnitude of magnetic field applied during magnetron deposition of Ta/F/AF/Ta structures, where F=Co, NiFe and AF=FeMn and IrMn, influences the uniaxial and unidirectional anisotropy, magnetization and the exchange bias blocking temperature. The deposition field effects on the bilayer structure are compared with the effects on a similar structure, but without antiferromagnetic layer. The exchange bias blocking temperature of investigated structures is found to be significantly lower than the Néel temperature of a bulk antiferromagnet. The origin of the observed effects is shortly discussed.

scholarly journals Effect of Magnetic Field and Temperature on the Exchange Bias in Phase-Separated Nd1-xSrxCoO3(x=0.10, 0.15)

2015 ◽  
Vol 9 (1) ◽  
pp. 56-59 ◽  
Author(s):  
Yi-Yun Yang
Keyword(s):  
Magnetic Field ◽  
Exchange Bias ◽  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Freezing Temperature ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Magnetic Field Axis ◽  
Coexisting Phases ◽  
The Magnetic Field

The exchange bias phenomena of phase-separated Nd1-xSrxCoO3(x=0.10, 0.15) samples were systematically investigated in this paper. The samples were prepared using conventional solid state reaction method. When the NdSrCoO samples cooled down in magnetic field below freezing temperature, the hysteresis loops shifted along the magnetic field axis. Moreover, exchange bias of Nd1-xSrxCoO3 is strongly dependent on the field and the temperature. The influence of magnetic field on the relative ratio of the coexisting phases may be responsible for these behaviors. Therefore, our study confirmed that in phase-separated system, the exchange coupling at the interface between the ferromagnetism clusters and the spin glass regions may induce interfacial exchange anisotropy.

scholarly journals Translatory and rotatory motion of exchange-bias capped Janus particles controlled by dynamic magnetic field landscapes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rico Huhnstock ◽  
Meike Reginka ◽  
Andreea Tomita ◽  
Maximilian Merkel ◽  
Kristina Dingel ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Exchange Bias ◽  
Pulse Sequence ◽  
Pulse Sequences ◽  
Janus Particles ◽  
Particle Rotation ◽  
Layer System ◽  
Applied Pulse ◽  
Magnetization State ◽  
Analyte Detection

AbstractMagnetic Janus particles (MJPs), fabricated by covering a non-magnetic spherical particle with a hemispherical magnetic in-plane exchange-bias layer system cap, display an onion magnetization state for comparably large diameters of a few microns. In this work, the motion characteristics of these MJPs will be investigated when they are steered by a magnetic field landscape over prototypical parallel-stripe domains, dynamically varied by superposed external magnetic field pulse sequences, in an aqueous medium. We demonstrate, that due to the engineered magnetization state in the hemispherical cap, a comparably fast, directed particle transport and particle rotation can be induced. Additionally, by modifying the frequency of the applied pulse sequence and the strengths of the individual field components, we observe a possible separation between a combined or an individual occurrence of these two types of motion. Our findings bear importance for lab-on-a-chip systems, where particle immobilization on a surface via analyte bridges shall be used for low concentration analyte detection and a particle rotation over a defined position of a substrate may dramatically increase the immobilization (and therefore analyte detection) probability.

Oscillatory Angular Dependence of Exchange Bias for Epitaxial NiO-Co (001) Bilayers

2001 ◽  
Vol 674 ◽  
Author(s):  
S. Dubourg ◽  
J.F. Bobo ◽  
B. Warot ◽  
E. Snoeck ◽  
J.C. Ousset
Keyword(s):  
Magnetic Field ◽  
Exchange Bias ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Field Application ◽  
Zero Field ◽  
Sign Change ◽  
Realistic Description ◽  
Sputter Deposited ◽  
The Magnetic Field

ABSTRACTWe have sputter-deposited NiO-Co bilayers on MgO (001) substrates. NiO grows epitaxially on MgO at 900°C and subsequently the room deposited 80 Åthick Co films have a fcc crystal structure in epitaxy with the oxide underlayer. These samples were warmed up to 300° C and then zero-field or field cooled through the NiO Néel temperature (a 300 Oe magnetic field was applied along the [100] or the [110] MgO axis). Magnetic hysteresis loops were obtained by magneto-optical Kerr effect, the magnetic field being oriented in the plane of the substrate for various angles α with respect to the [100] direction. The usually expected behavior for such experiments is a smooth angular α dependence of the exchange bias HE close to a cosine with only one sign change over 180°. The high crystallographic coherence of our NiO/Co bilayers induces a very unusual oscillatory HE (α) dependence with several sign changes according to the NiO axis field application. Despite of the Co magnetization switching mechanism which is not a pure coherent rotation, we propose a Stoner-Wohlfhart model including four fold anisotropy and unidirectional exchange anisotropy giving a realistic description of these typical magnetic properties.

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