scholarly journals Structural, electronic and magnetic properties of YMnO3/La0.7Sr0.3MnO3heterostructures

2014 ◽  
Vol 47 (3) ◽  
pp. 1054-1064 ◽  
Author(s):  
Amitesh Paul ◽  
Carlos Zandalazini ◽  
Pablo Esquinazi ◽  
Carmine Autieri ◽  
Biplab Sanyal ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Hysteresis Loops ◽  
Magnetic Interactions ◽  
Ferromagnetic Phase ◽  
High Coercivity ◽  
Vertical Shift ◽  
Intrinsic Nature ◽  
Lattice Constants ◽  
Horizontal Shift ◽  
Magnetization Axis

Heterostructures with competing magnetic interactions are often exploited for their tailored new functionalities. Exchange bias is one such outcome of interfacial coupling across ferromagnetic–antiferromagnetic, multiferroic–ferromagnetic, two antiferromagnetic, or antiferromagnetic and paramagnetic interfaces. Apart from the usual horizontal shift of the hysteresis loop (exchange bias shift), a small `vertical shift' of the hysteresis loops along the magnetization axis has also been seen, but it was always relatively small. Recently, an unusually large `vertical shift' in epitaxial bilayer heterostructures comprising ferromagnetic La0.7Sr0.3MnO3and multiferroic orthorhombic YMnO3layers was reported. Here, using polarized neutron reflectometry, the magnetic proximity effect in such bilayers has been investigated. A detailed magnetic depth profile at the interface, elucidating the intrinsic nature of the vertical shift in such heterostructures, is reported. Further corroboration of this observation has been made by means of first-principles calculations, and the structural and electronic properties of YMnO3/La0.7Sr0.3MnO3heterostructures are studied. Although in the bulk, the ground state of YMnO3is anE-type antiferromagnet, the YMnO3/La0.7Sr0.3MnO3heterostructure stabilizes the ferromagnetic phase in YMnO3in the interface region. It is found that, in the hypothetical ferromagnetic phase of bulk YMnO3, the polarization is suppressed, and owing to a large difference between the lattice constants in theabplane a strong magnetocrystalline anisotropy is present. This anisotropy produces a high coercivity of the unusual ferromagnetic YMnO3phase at the interface, which is responsible for the large vertical shift observed in experiment.

Exchange bias and anomalous vertical shift of the hysteresis loops in milled Fe/MnO2 material

2006 ◽  
Vol 299 (1) ◽  
pp. 11-20 ◽  
Author(s):  
E.C. Passamani ◽  
C. Larica ◽  
C. Marques ◽  
J.R. Proveti ◽  
A.Y. Takeuchi ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Hysteresis Loops ◽  
Vertical Shift

EXCHANGE BIAS-LIKE PHENOMENON IN LU DOPED La0.1Bi0.9FeO3 CERAMICS

2013 ◽  
Vol 28 (01) ◽  
pp. 1350194 ◽  
Author(s):  
X. HAI ◽  
W. F. LIU ◽  
Y. F. GONG ◽  
H. ZHANG ◽  
P. WU ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solid State ◽  
Applied Magnetic Field ◽  
Exchange Bias ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Vertical Shift ◽  
Reaction Method ◽  
Horizontal Shift ◽  
Large Anisotropy

The polycrystalline La 0.1 Lu x Bi 0.9-x FeO 3(x = 0, 0.01, 0.03, 0.05, 0.1 and 0.2) compounds were synthesized by a conventional solid-state reaction method. An unusual exchange bias-like (EB-like) phenomenon was found in this system. Both horizontal shift (Hs) and vertical shift (Ms) are observed simultaneously. Moreover, the horizontal shift displays a similar trend to the vertical shift with the variation of Lu content and the variation of maximum applied magnetic field, revealing that the horizontal shift and the vertical shift are closely correlated. We propose that the horizontal shift may be related to the exchange interaction between two different canted-AFM phases and the vertical shift is related to the large anisotropy of LuFeO 3.

Exchange Bias in CrO2/Cr2O3 Bilayer Thin Films

2006 ◽  
Vol 45 ◽  
pp. 2528-2533 ◽  
Author(s):  
S. Srinath ◽  
N.A. Frey ◽  
H. Srikanth ◽  
G.X. Miao ◽  
A. Gupta
Keyword(s):  
Thin Films ◽  
Magnetic Anisotropy ◽  
Variable Thickness ◽  
Exchange Bias ◽  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Anisotropy Constant ◽  
Effective Magnetic Anisotropy ◽  
Large Anisotropy

We have investigated the exchange bias in CVD grown epitaxial CrO2/Cr2O3 bilayer thin films using hysteresis loops and resonant RF transverse susceptibility. M-H loops indicated an enhanced coercivity without appreciable loop shift and the transverse susceptibility in CrO2/Cr2O3 bilayers revealed features associated with both the ferromagnetic and antiferromagnetic phases. In addition, TS yielded large anisotropy constant (Keff) values depending on the fraction of Cr2O3 present. The large anisotropy fields observed cannot be accounted for by the variable thickness of CrO2 alone and are indicative of possible exchange coupling between CrO2 and Cr2O3 phases that significantly affects the effective magnetic anisotropy.

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.

Monte Carlo Simulations of the Exchange Bias Effect in Heusler Ni50Mn37.5Sb12.5 Alloys Using Real Unit Cell

2011 ◽  
Vol 1310 ◽  
Author(s):  
Vasiliy D. Buchelnikov ◽  
Ivan A. Taranenko ◽  
Vladimir V. Sokolovskiy ◽  
Sergey V. Taskaev ◽  
Mikhail A. Zagrebin ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Periodic Boundary ◽  
Three Dimensional ◽  
Periodic Boundary Conditions ◽  
Bias Field ◽  
Magnetic Interactions ◽  
Bias Effect ◽  
Exchange Bias Effect ◽  
Cubic Lattice ◽  
Coordination Spheres

ABSTRACTIn present work we propose a theoretical model for investigation of the exchange bias effect in Ni50Mn37.5Sb12.5 alloy. In the model, we use a three-dimensional cubic lattice with periodic boundary conditions. Also we take into account the magnetic interactions between atoms in 1st, 2nd and 3rd coordination spheres and the ferromagnetic and antiferromagnetic anisotropy terms. It is shown that the obtained theoretical temperature dependence of the exchange bias field for Ni50Mn37.5Sb12.5 alloy is close to the experimental data.

Crystal Distortions Associated with Magnetic Ordering in the Antiferromagnetic Compound VF2

1970 ◽  
Vol 14 ◽  
pp. 433-440
Author(s):  
W. S. McCain ◽  
D. L. Albright ◽  
W. O. J. Boo
Keyword(s):  
Single Crystal ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Magnetic Ordering ◽  
The Body ◽  
The Other ◽  
Magnetic Interactions ◽  
One Dimensional ◽  
Lattice Constants ◽  
Vanadium Ions

AbstractLattice constants were measured as a function of temperature by single crystal diffracrometry in the temperature range which includes the Néel temperature of VF2(TN= 7°K). The lattice constants of VF2(D4h14=P42m n m) were measured from room temperature down to 4.2°K. In this range rhe tetragonal c-axis contracts 0.58% from 3.2359 Å (RT) to 3.2170 Å (4.2°K). On the other hand, the a-axes show a net expansion of 0.18% from 4.8023 Å (RT) to 4.8110 Å at 4.2°K. The temperature dependence of the lattice constants can be correlated with anisotropy of exchange forces. Vanadium Ions occupy the center and corner positions of the unit cell. Strong magnetic interactions are directed parallel to the c-axis >001< with considerably weaker interactions parallel to the body diagonals >111< The relative strengths of the two exchange integrals are J >001< = 50 J >111<. As a consequence the magnetic ordering is one-dîmensional along the c-axis and the associated distortions arise from the strong magnetic interactions along this axis.

scholarly journals Exchange bias in ferromagnetic bilayers with orthogonal anisotropies: the case of GaMnAsP/GaMnAs combination

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Suho Choi ◽  
Seul-Ki Bac ◽  
Xinyu Liu ◽  
Sanghoon Lee ◽  
Sining Dong ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Easy Axis ◽  
Initial Conditions ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
The Other ◽  
Planar Hall Effect ◽  
Magnetic Layers ◽  
Out Of Plane ◽  
Magnetic Hysteresis Loops

Abstract We report the observation of exchange bias in a ferromagnetic Ga0.94Mn0.06As0.77P0.23/ Ga0.94Mn0.06As bilayer, in which the easy axis in one layer is oriented out-of-plane, and in the other in-plane. Magnetization reversal in this system is explored using planar Hall effect (PHE) measurements under various initial conditions and with various field-cooling orientations. Our results show that the two magnetic layers are ferromagnetically exchange-coupled, and that such coupling results in pronounced exchange-bias-like shifts of magnetic hysteresis loops during reversal of in-plane magnetization. The presence of exchange bias in this system can be understood on the basis of magnetic closure domains formed in the layer with the out-of-plane easy axis.

scholarly journals The Physical and Magnetic Properties of Electrodeposited Co-Fe Nanocoating with Different Deposition Times

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Koay Mei Hyie ◽  
Wan Normimi Roslini Abdullah ◽  
Nor Azrina Resali ◽  
W. T. Chong ◽  
Z. Salleh ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Deposition Time ◽  
Hysteresis Loops ◽  
High Coercivity ◽  
Crystallographic Structure ◽  
Irregular Shapes ◽  
Soft Ferromagnetic ◽  
Cobalt Iron ◽  
Structure Surface ◽  
Fesem Micrographs

Using the electrodeposition process, cobalt-iron (Co-Fe) nanocrystalline coatings were successfully synthesized onto stainless steel in deposition times of 30, 60, and 90 minutes. The temperature used throughout the process was 50°C in an acidic environment of pH 3. By changing the deposition time, physical properties such as phase and crystallographic structure, surface morphology, grain size, microhardness, and magnetic properties of Co-Fe coatings were examined. FESEM micrographs showed that the grain sizes of the coatings were in the range from 57.9 nm to 70.2 nm. Dendrite and irregular shapes were found in the microstructure of Co-Fe nanocoating. The Co-Fe nanocrystalline coating prepared in a deposition time of 90 minutes achieved the highest microhardness of 339 HVN. The magnetic properties associated with Co-Fe nanocoating at longer deposition times show greater coercivity,Hc, and saturation magnetization,Ms, values of 56.43 Oe and 70.45 eμ/g, respectively. The M-H curves for all the Co-Fe coatings exhibited soft ferromagnetic behaviour with narrow hysteresis loops. It was found that increasing the deposition time also improved the microhardness and magnetic properties of Co-Fe nanocoating, which is much needed for long-life high-coercivity magnetic strip card applications.

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