Exchange Bias Properties in Bulk Ni45Co5Mn38Sn12 Heusler Alloy

2014 ◽  
Vol 875-877 ◽  
pp. 272-276 ◽  
Author(s):  
Chao Jing ◽  
Ye Jun Yang ◽  
Dong Hua Yu ◽  
Zhe Li ◽  
Xiao Long Wang ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Exchange Bias ◽  
Heusler Alloy ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Bias Field ◽  
Magnetic Hysteresis Loop ◽  
Zero Field ◽  
Co Substitution ◽  
Exchange Bias Field

We report the exchange bias properties in the bulk Ni45Co5Mn38Sn12quaternary Heusler alloy. The ferromagnetic (FM) –antiferromagnetic (AFM) interactions get reinforced after the Co substitution for Ni in the Ni-Mn-Sn alloy, which increase the exchange bias field (HE). A maximum shift in hysteresis loops of 306 Oe was observed in the 10 kOe field cooled sample. The origin of this large exchange bias field has been discussed. Magnetic hysteresis loop obtained in the zero field cooled (ZFC) mode shows double-shifted loop, and the reason of this phenomenon has been explained in detail.

scholarly journals The inverted hysteresis loops and exchange bias effects in amorphous/nanocrystalline Fe72Cu1V4Si15B8 ribbons at room temperature

2020 ◽  
Vol 52 (3) ◽  
pp. 283-298
Author(s):  
Radoslav Surla ◽  
Nebojsa Mitrovic ◽  
Milica Vasic ◽  
Dragica Minic
Keyword(s):  
Hysteresis Loop ◽  
Exchange Bias ◽  
Room Temperature ◽  
Structural Changes ◽  
Annealing Temperature ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Nanocrystalline Structure ◽  
Bias Field ◽  
Thermally Induced

?he influence of thermally induced microstructural transformations on magnetic properties of Fe72Cu1V4Si15B8 ribbon with combined amorphous/nanocrystalline structure is presented. The experiments showed that thermally induced structural changes are in correlation with the appearance of magnetic hysteresis, i.e. with inverted hysteresis loops (IHL) and exchange bias (EB) effects. It was found that the ratio of surface to volume of a ribbon sample have an influence on hysteresis loop appearance. The inverted hysteresis loops were observed for the 1.5 mm wide and 55 ?m thick alloy samples shorter than 10 mm, but for the samples longer than 10 mm hysteresis loops were normal. With an increase of annealing temperature, a shift of the hysteresis loops measured at room temperature was noticed. The highest positive exchange bias field Heb was observed for the sample annealed at 723 K, together with the lowest magnetic field at which the changes from inverted to normal hysteresis loop occurred. Annealing at the temperature of 823 K resulted in negative Heb.

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.

A Dissipative Quantum Dynamic Approach to Magnetic Hysteresis Loop and Magnetization Relaxation for Molecule Magnet Mn12

2003 ◽  
Vol 17 (17) ◽  
pp. 3215-3224
Author(s):  
Yuanchang Su ◽  
Yongjin Jiang
Keyword(s):  
Hysteresis Loop ◽  
Time Evolution ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Hysteresis Loop ◽  
Quantum Dynamic ◽  
Magnetization Relaxation ◽  
Resonant Tunnelling ◽  
State Evolution ◽  
Different Temperatures

A new approach to the magnetic hysteresis loop and magnetization relaxation of molecule magnet, Mn12, is presented. The method, so called "quasi-thermal equilibrium (QTE) + erase phase (EP)" (QTE + EP), leads the dissipation in state evolution. The method gives an method to approach an irreversible quantum dynamic tunnelling and time evolution of system and straightly leads the hysteresis loops. The QTE can work well for the double-well system and is able to be extended to the multi-wells quantum system. The EP is based on the physics of random interaction with the environment that results the phase de-coherence or say "re-initial" of the phase of quantum state during the time evolution. The stairs in the magnetic loops of Mn12 we have obtained quantitatively show the quantum resonant tunnelling. The relaxation of magnetization from initial lowest state is calculated for different temperatures and well shows the exponential behavior. The theoretical results well agree with the experiments.

scholarly journals Observation of Negative Magnetic Hysteresis Loop in ZnO Thin Films

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Micah Haseman ◽  
Pooneh Saadatkia ◽  
David Winarski ◽  
Armando Hernandez ◽  
Matt Kusz ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Diluted Magnetic Semiconductors ◽  
Magnetic Semiconductors ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Magnetic Hysteresis Loop ◽  
Structural Defects ◽  
Zno Films ◽  
Doped Zno

We report on the observation of an unusual negative magnetic hysteresis loop in ZnO thin film codoped with cobalt and aluminum (Co-Al:ZnO), while other transition-metal-doped ZnO films, such as Cu-doped ZnO and Mn-doped ZnO, exhibit normal hysteresis loops. The unusual magnetic behavior is ascribed to the presence of double magnetic layers with different magnetic moments due to the change of structural defects across the film layers. Positron annihilation measurements confirmed the presence of unique microstructural changes in the Co-Al:ZnO film. This study shows that defects in diluted magnetic semiconductors may induce not only ferromagnetism but also novel magnetic behaviors.

scholarly journals Обменная пружина в гетероструктуре с низкотемпературным ферромагнетиком Pd-=SUB=-0.96-=/SUB=-Fe-=SUB=-0.04-=/SUB=-

2019 ◽  
Vol 45 (8) ◽  
pp. 12
Author(s):  
И.В. Янилкин ◽  
Э.Т. Мухаметова ◽  
И.Р. Вахитов ◽  
А.И. Гумаров ◽  
Р.В. Юсупов ◽  
...  
Keyword(s):  
Thin Film ◽  
Exchange Bias ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Hysteresis Loop ◽  
Vacuum System ◽  
Exchange Spring ◽  
Ferromagnetic Layers ◽  
Micromagnetic Modeling ◽  
Magnetic Hysteresis Loops

AbstractThe exchange bias of the magnetic hysteresis loop and the exchange-spring effect have been observed in thin-film heterostructures comprising layers of Pd_0.96Fe_0.04 low-temperature ferromagnet, metallic cobalt, and cobalt monoxide (CoO) grown on single-crystalline sapphire by methods of magnetron sputtering and molecular beam epitaxy in an ultrahigh-vacuum system. It is established that the exchange anisotropy of Pd_0.96Fe_0.04 layer in Pd_0.96Fe_0.04/CoO/Co/Al_2O_3 thin-film heterostructure is absent and the exchange-spring effect in this system is not manifested. In the case of a Pd_0.96Fe_0.04/Co/CoO/Al_2O_3 structure, it is shown that, according to the results of magnetometric measurements, the inversion of the order of antiferromagnetic and ferromagnetic layers leads to pinning of the magnetic moment of Pd_0.96Fe_0.04 layer at the interface with cobalt and to realization of the exchange-spring effect. Additional evidence in favor of this interpretation was obtained using the micromagnetic modeling of magnetic hysteresis loops.

MULTIFERROISM AND MAGNETOELECTRIC COUPLING IN NANO-MICROSCALE LEAD-FREE COMPOSITE BY 0.3Co-FERRITE AND 0.7(K0.5Na0.5)NbO3-BASED FERROELECTRIC MATRIX

2011 ◽  
Vol 25 (32) ◽  
pp. 4481-4488 ◽  
Author(s):  
YUN ZHOU ◽  
XINYAN WANG ◽  
LI LI ◽  
YULING SU ◽  
JINCANG ZHANG ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Dilution Effect ◽  
Magnetic Hysteresis Loop ◽  
Lead Free ◽  
Voltage Coefficient ◽  
Polarization Electric Field ◽  
Magnetic Hysteresis Loops ◽  
Potential Use

Nontoxic lead-free multiferroic composites are synthesized by incorporating the dispersed 0.3 CoFe 2 O 4 (CFO) ferromagnetic nanoparticles into 0.7( K 0.5 Na 0.5) NbO 3- LiSbO 3 (KNN-LS5.2) ferroelectric micromatrix. The multiferroicity of the composite can be verified by polarization-electric field hysteresis loop and magnetic hysteresis loop. The composite exhibits excellent magnetic properties. A dilution effect is observed in magnetic hysteresis loops. The field dependence of ME voltage coefficient is given as a function of magnetic field from -4 kOe to 4 kOe with a maximum magnetoelectric voltage coefficient of 10.7 mV ⋅ cm -1⋅ Oe -1 at the frequency of 1 kHz. It is a very high value in the lead-free magnetoelectric composites system for the potential use on multifunctional devices.

Observation of large exchange bias field in Mn rich NiMnAl Heusler alloy thin film

2021 ◽  
Vol 532 ◽  
pp. 167964
Author(s):  
Archana Mishra ◽  
Paritosh Dubey ◽  
Ramesh Chandra ◽  
Saurabh Kumar Srivastava
Keyword(s):  
Thin Film ◽  
Exchange Bias ◽  
Heusler Alloy ◽  
Bias Field ◽  
Alloy Thin Film ◽  
Exchange Bias Field
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