Magnetic properties of iron cluster/chromium matrix nanocomposites

A custom-designed apparatus was used for the fine-tuned co-deposition of preformed Fe clusters into antiferromagnetic Cr matrices. Three series of samples with precisely defined cluster sizes, with accuracy to a few atoms, and controlled concentrations were fabricated, followed by a complete characterization of structure and magnetic performance. Relevant magnetic characteristics, reflecting the ferromagnetic/antiferromagnetic coupling between Fe clusters and the Cr matrix, i.e., blocking temperature, coercivity field, and exchange bias were measured and their dependence on cluster size and cluster concentration in the matrix was analyzed. It is evident that the blocking temperatures are clearly affected by both the cluster size and their concentration in the Cr matrix. In contrast the coercivity shows hardly any dependence on size or inter-cluster distance. The exchange bias was found to be strongly sensitive to the cluster size but not to the inter-cluster distances. Therefore, it was concluded to be an effect that is purely localized at the interfaces.

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Fabrication and Characterization of the Modified EV31-Based Metal Matrix Nanocomposites

Metals ◽

10.3390/met11010125 ◽

2021 ◽

Vol 11 (1) ◽

pp. 125

Author(s):

Seyed Kiomars Moheimani ◽

Mehran Dadkhah ◽

Mohammad Hossein Mosallanejad ◽

Abdollah Saboori

Keyword(s):

Thermal Expansion ◽

Mechanical Strength ◽

Metal Matrix ◽

Coefficient Of Thermal Expansion ◽

Structural Effect ◽

Metal Matrix Nanocomposites ◽

Mechanical Stirring ◽

Specific Strength ◽

The Matrix ◽

Matrix Nanocomposites

Metal matrix nanocomposites (MMNCs) with high specific strength have been of interest for numerous researchers. In the current study, Mg matrix nanocomposites reinforced with AlN nanoparticles were produced using the mechanical stirring-assisted casting method. Microstructure, hardness, physical, thermal and electrical properties of the produced composites were characterized in this work. According to the microstructural evaluations, the ceramic nanoparticles were uniformly dispersed within the matrix by applying a mechanical stirring. At higher AlN contents, however, some agglomerates were observed as a consequence of a particle-pushing mechanism during the solidification. Microhardness results showed a slight improvement in the mechanical strength of the nanocomposites following the addition of AlN nanoparticles. Interestingly, nanocomposite samples were featured with higher electrical and thermal conductivities, which can be attributed to the structural effect of nanoparticles within the matrix. Moreover, thermal expansion analysis of the nanocomposites indicated that the presence of nanoparticles lowered the Coefficient of Thermal Expansion (CTE) in the case of nanocomposites. All in all, this combination of properties, including high mechanical strength, thermal and electrical conductivity, together with low CTE, make these new nanocomposites very promising materials for electro packaging applications.

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Tailoring exchange bias in reentrant spin glass by ferromagnetic cluster size engineering

APL Materials ◽

10.1063/5.0036910 ◽

2021 ◽

Vol 9 (1) ◽

pp. 011104

Author(s):

Fanghua Tian ◽

Xiaoqin Ke ◽

Kaiyan Cao ◽

Dingchen Wang ◽

Qizhong Zhao ◽

...

Keyword(s):

Spin Glass ◽

Exchange Bias ◽

Cluster Size ◽

Ferromagnetic Cluster ◽

Reentrant Spin Glass

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Improved exchange bias and blocking temperature of PtCr/PtMn bilayer antiferromagnets

AIP Advances ◽

10.1063/1.5079489 ◽

2019 ◽

Vol 9 (3) ◽

pp. 035306 ◽

Cited By ~ 2

Author(s):

Masamichi Saito ◽

Fumihito Koike

Keyword(s):

Exchange Bias ◽

Blocking Temperature

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Effect of Increasing the Strength of Aluminum Matrix Nanocomposites Reinforced with Microadditions of Multiwalled Carbon Nanotubes Coated with TiC Nanoparticles

Nanomaterials ◽

10.3390/nano9111596 ◽

2019 ◽

Vol 9 (11) ◽

pp. 1596 ◽

Cited By ~ 5

Author(s):

Artemiy Aborkin ◽

Kirill Khorkov ◽

Evgeny Prusov ◽

Anatoly Ob’edkov ◽

Kirill Kremlev ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Aluminum Matrix ◽

High Energy ◽

High Tech ◽

Multiwalled Carbon ◽

The Matrix ◽

Tic Nanoparticles ◽

Matrix Nanocomposites

Aluminum matrix composites reinforced with multiwalled carbon nanotubes (MWCNTs) are promising materials for applications in various high-tech industries. Control over the processes of interfacial interaction in Al/MWCNT composites is important to achieve a high level of mechanical properties. The present study describes the effects of coating MWCNTs with titanium carbide nanoparticles on the formation of mechanical properties and the evolution of the reinforcement structure in bulk aluminum matrix nanocomposites with low concentrations of MWCNTs under conditions of solid-phase consolidation of ball-milled powder mixtures. Using high-energy ball milling and uniaxial hot pressing, two types of bulk nanocomposites based on aluminum alloy AA5049 that were reinforced with microadditions of MWCNTs and MWCNTs coated with TiC nanoparticles were successfully produced. The microstructural and mechanical properties of the Al/MWCNT composites were investigated. The results showed that, on the one hand, the TiC nanoparticles on the surface of the MWCNT hybrid reinforcement reduced the damage of reinforcement under the intense exposure of milling bodies, and on the other hand, they reduced the contact area of the MWCNTs with the matrix material (acting as a barrier interface), which also locally inhibited the reaction between the matrix and the MWCNTs.

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Large perpendicular exchange bias and high blocking temperature in Al-doped Cr2O3/Co thin film systems

Applied Physics Express ◽

10.7567/apex.10.073003 ◽

2017 ◽

Vol 10 (7) ◽

pp. 073003 ◽

Cited By ~ 7

Author(s):

Tomohiro Nozaki ◽

Yohei Shiokawa ◽

Yukie Kitaoka ◽

Yohei Kota ◽

Hiroshi Imamura ◽

...

Keyword(s):

Thin Film ◽

Exchange Bias ◽

Blocking Temperature

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UNITARY LOCAL INVARIANCE

International Journal of Quantum Information ◽

10.1142/s0219749905001523 ◽

2005 ◽

Vol 03 (04) ◽

pp. 655-659 ◽

Cited By ~ 5

Author(s):

MATTEO G. A. PARIS

Keyword(s):

Singular Values ◽

Complete Characterization ◽

Bipartite State ◽

Local Invariance ◽

The Matrix ◽

Pure States

We address unitary local (UL) invariance of bipartite pure states. Given a bipartite state |Ψ〉〉 = ∑ij ψij |i〉1 ⊗ |j〉2 the complete characterization of the class of local unitaries U1 ⊗ U2 for which U1 ⊗ U2|Ψ〉〉 = |Ψ〉〉 is obtained. The two relevant parameters are the rank of the matrix Ψ, [Ψ]ij = ψij, and the number of its equal singular values, i.e. the degeneracy of the eigenvalues of the partial traces of |Ψ〉〉.

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

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.190.93 ◽

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.

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Magnetic properties of iron cluster/chromium matrix nanocomposites

nano Online ◽

10.1515/nano.bjneah.6.117 ◽

2016 ◽

Author(s):

Arne Fischer ◽

Robert Kruk ◽

Di Wang ◽

Horst Hahn

Keyword(s):

Magnetic Properties ◽

Iron Cluster ◽

Matrix Nanocomposites

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Study of the Nanocomposite cBN/TiC-SWCNTs by Field Actived Sparck Plasma Sintering Process

Journal of Advances in Nanotechnology ◽

10.14302/issn.2689-2855.jan-20-3243 ◽

2020 ◽

Vol 1 (2) ◽

pp. 14-29

Author(s):

Badis Bendjemil ◽

Mohamed Mouyane ◽

Jacques G. Noudem ◽

Jérôme Bernard ◽

...

Keyword(s):

Carbon Nanotubes ◽

Fracture Toughness ◽

Sintering Process ◽

X Ray Diffraction ◽

Protective Layers ◽

Plasma Sintering ◽

The Matrix ◽

Ceramics Matrix ◽

Walled Carbon Nanotubes ◽

Matrix Nanocomposites

Cubic boron nitrid (cBN) bonded TiC and alloyed with single walled carbon nanotubes (SWCNTs or NC) ceramics matrix nanocomposites (CMNCs) tools were manufacturated by a field actived sparck plasma sintering processus (FASPS). The effects of cBN-TiC ratio, carbon nanotubes and optimisation of the sintering process on the microstructure, densification in addition mechanical and vibronic properties of NC-cBN-TiC nanocomposites were studied. The results showed that for the nanocomposite cBN-TiC vol. ratio of 8:2 with 0.1 wt% NC, it was found that microhardness incresses significantly with addition of carbon nanotubes exhibited the highest microhardness and fracture toughness. After sintering of the samples at 1800 °C, 10 mn, 75 MPa of cBN–TiC1-x, x=0.8 with and without addition of 0.1 wt% NC were characterized using field emission scanning electron microscopy (FESEM) and X-ray diffraction. The samples exhibited a dense polycrystalline structure. From the resonant Raman scattering we can locate the vibration frequency of the transformation cBN to hexagonal boron nitrid (hBN) and formation of secondary hard phase TiB2to consolid the (CMNCs) tools. The final product is hBN-TiC-TiB2-NC.The best product contained cBNx-TiC1-x (x=0.8)-0.1 wt % NC which was sintered at 1800 °C, 75 MPa for 10 mn. The Vickers hardness of cBN-TiC1-x (x=0.8) incresses with NC incorporation in the matrix The indentation fracture toughness was calculated to be 12.30 MPa m1/2 for cBNx-TiC1-x (x=0.8 -0.1 wt % NC ceramics matrix nanocomposite (CMNCs) tools with excellent wear resistant will be confirmed. The wear of cBN-TiC of the composites tools have shown that this is predominantly a chemical process involving the interaction of the tool with its environment and is restricted by the formation of protective layers on the exposed faces of the tool by the addition of carbon nanotubes (NC). The wear features of tools used in fine cutting tests under identical conditions will be compared and the results will be interpreted in terms of the existing models for the wear of cBN -based nanomaterials by the effects of the additives in the modified tools

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