Magnetic Properties of Proton Irradiated Fe2.7GeTe2 Bulk Crystals

MRS Advances ◽  
2019 ◽  
Vol 4 (40) ◽  
pp. 2185-2190
Author(s):  
R. Olmos ◽  
A. Cosio ◽  
C. L. Saiz ◽  
L. M. Martinez ◽  
L. Shao ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Proton Irradiation ◽  
Magnetic Behavior ◽  
Bulk Crystals ◽  
Temperature Dependent ◽  
Itinerant Ferromagnet ◽  
Surface Iron ◽  
Before And After ◽  
The Magnetic Field

Abstractvan der Waals (vdW) magnetic materials show promise in being the foundation for future spintronic technology. The magnetic behavior of Fe2.7GeTe2 (FGT), a vdW itinerant ferromagnet, was investigated before and after proton irradiation. Proton irradiation of the sample was carried out at a fluence of 1×1018 cm-2. The magnetization measurements revealed a small increase of saturation magnetization (Ms) of about 4% upon proton irradiation of the sample, in which, the magnetic field was applied parallel to the c-axis. X-ray photoelectron spectroscopy for pristine and irradiated FGT revealed a general decrease in intensity after irradiation for Ge and Te and an increase in peak intensity of unavoidable surface iron oxide. Furthermore, no noticeable change in the Curie temperature (TC =152 K) is observed in temperature dependent magnetization variation. This work signifies the importance of employing protons in tuning the magnetic properties of vdW materials.

Magnetic properties of some Fe–S six-membered ring compounds

2002 ◽  
Vol 80 (12) ◽  
pp. 1646-1649 ◽  
Author(s):  
Ping Liu ◽  
Jia Cheng Liu ◽  
Jian Wang ◽  
Jian Kai Cheng ◽  
Wen Jie Li ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Behavior ◽  
Cluster Compounds ◽  
Spin Interaction ◽  
Fe Model ◽  
Temperature Dependent ◽  
Magnetic Exchange ◽  
Ring Compounds ◽  
First Time ◽  
Active Centres

The Fe3S3 cluster is an important component located in the active centres of some iron–sulfur proteins. The magnetic properties of three Fe3S3 compounds have been studied for the first time by fitting the temperature-dependent magnetic susceptibilities. The calculated g factors and J couplings reproduce the magnetic behavior of such compounds very well. There is an antiferromagnetic spin interaction between pairs of magnetic centers in the Fe3S3 cluster compounds. The magnetic exchange of Fe-S-Fe model magnetic molecules is discussed.Key words: Fe3S3 compounds, magnetic, antiferromagnetic.

MAGNETIC PROPERTIES OF MnO2 SHRIMPS-LIKE NANOSTRUCTURES SYNTHESIZED BY HYDROTHERMAL ROUTE

2013 ◽  
Vol 27 (29) ◽  
pp. 1350215 ◽  
Author(s):  
ARBAB MOHAMMAD TOUFIQ ◽  
FENGPING WANG ◽  
QURAT-UL-AIN JAVED ◽  
YAN LI
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
Vibrating Sample Magnetometer ◽  
Temperature Dependent ◽  
Néel Temperature ◽  
Hydrothermal Route ◽  
X Ray ◽  
Field Dependent ◽  
Temperature Dependent Magnetization

In this paper, we report the field-dependent magnetization (M–H) and temperature-dependent magnetization (M–T) properties of hexagonal MnO 2 shrimps-like nanostructures which have been successfully synthesized by hydrothermal route using KMnO 4 and HNO 3 as precursors. The magnetic properties were characterized by vibrating sample magnetometer (VSM). Field-dependent magnetization (M–H) measured at 300 K exhibit paramagnetic nature of MnO 2 nanostructures, while an antiferromagnetic component is observed for the as-prepared product at 55 K. The Néel temperature (TN) is calculated as 89 K by plotting temperature-dependent magnetization (M–T) curve for the as-prepared MnO 2 nanostructures. X-ray photoelectron spectroscopy (XPS) is employed to calculate the binding energies of Mn (2p3/2, 2p1/2) and O (1s) observed in the spectrum.

Effect of Homogenization on the Microstructure and Magnetic Properties of Direct Laser-Deposited Magnetocaloric Ni43Co7Mn39Sn11

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Erica Stevens ◽  
Katerina Kimes ◽  
Volodymyr Chernenko ◽  
Patricia Lázpita ◽  
Anna Wojcik ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Additive Manufacturing ◽  
Magnetic Behavior ◽  
Production Method ◽  
Laser Deposition ◽  
Direct Laser Deposition ◽  
Direct Laser ◽  
Before And After ◽  
Columnar Grains ◽  
And Performance

Abstract Transitioning current cooling and refrigeration technologies to solid-state cooling leveraging the magnetocaloric effect would improve efficiency and eliminate a harmful influence on the environment. Employing additive manufacturing as a production method would increase geometrical freedom and allow designed channels and porosity in heat exchangers made from magnetocaloric materials, to increase surface area for heat transfer via a fluid. This study is the first to demonstrate a successful deposition of the Ni43Co7Mn39Sn11 magnetocaloric material by direct laser deposition. Samples were defined as either properly- or overbuilt, and representative ones were characterized for microstructural features before and after homogenization heat treatment, as well as magnetic behavior and constituent phases. As-built microstructures consisted of dendrites, columnar grains, and elongated cells, with a mix of both austenite and 7M martensite phases. Homogenization increased the fraction of 7M martensite, and encouraged distinct equiaxed and columnar grains, eliminating dendrites and cellular structures. The increased fraction of the weak magnetic martensitic phase also resulted in a strong reduction of the saturation magnetization. Some differences in structure and performance may be related to an energy density difference causing higher Mn loss in the properly built sample, with a lower powder-to-energy input ratio. As a whole, it is found that direct laser deposition (DLD) additive manufacturing of Ni-Mn-based magnetocaloric material is very promising, since representative transformation, phase state, and magnetic properties have been achieved in this study.

Magnetic Properties of xCeO2•(50 − x) PbO•50B2O3 Glasses and Glass Ceramics

2017 ◽  
Vol 13 (1) ◽  
pp. 4486-4494 ◽  
Author(s):  
G.El Damrawi ◽  
F. Gharghar
Keyword(s):  
Magnetic Properties ◽  
Large Scale ◽  
Glass Ceramics ◽  
Magnetic Behavior ◽  
Crystal Formation ◽  
Dual Roles ◽  
Effective Agent ◽  
Ordered Structures ◽  
Essential Change

Cerium oxide in borate glasses of composition xCeO2·(50 − x)PbO·50B2O3 plays an important role in changing both microstructure and magnetic behaviors of the system. The structural role of CeO2 as an effective agent for cluster and crystal formation in borate network is clearly evidenced by XRD technique. Both structure and size of well-formed cerium separated clusters have an effective influence on the structural properties. The cluster aggregations are documented to be found in different range ordered structures, intermediate and long range orders are the most structures in which cerium phases are involved. The nano-sized crystallized cerium species in lead borate phase are evidenced to have magnetic behavior.  The criteria of building new specific borate phase enriched with cerium as ferrimagnetism has been found to keep the magnetization in large scale even at extremely high temperature. Treating the glass thermally or exposing it to an effective dose of ionized radiation is evidenced to have an essential change in magnetic properties. Thermal heat treatment for some of investigated materials is observed to play dual roles in the glass matrix. It can not only enhance alignment processes of the magnetic moment but also increases the capacity of the crystallite species in the magnetic phases. On the other hand, reverse processes are remarked under the effect of irradiation. The magnetization was found to be lowered, since several types of the trap centers which are regarded as defective states can be produced by effect of ionized radiation. 

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

scholarly journals Effect of sizing agent on interfacial properties of carbon fiber-reinforced PMMA composite

2021 ◽  
Vol 30 ◽  
pp. 2633366X2097865
Author(s):  
Li Jian
Keyword(s):  
Shear Strength ◽  
Surface Treatment ◽  
Photoelectron Spectroscopy ◽  
Resin Composite ◽  
Contact Angles ◽  
Static Contact ◽  
Before And After ◽  
C Value ◽  
Interlayer Shear Strength ◽  
Pmma Resin

The surface treatment of carbon fibers (CFs) was carried out using a self-synthesized sizing agent. The effects of sizing agent on the surface of CFs and the interface properties of CF/polymethyl methacrylate (PMMA) composites were mainly studied. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and static contact angle were used to compare and study the CFs before and after the surface treatment, including surface morphology, surface chemical element composition, and wettability of the surface. The influence of sizing agent on the mechanical properties of CF/PMMA resin composite interface was investigated. The results show that after sizing treatment, the CF surface O/C value increased by 35.1% and the contact angles of CF and resin decreased by 16.2%. The interfacial shear strength and interlayer shear strength increased by 12.6%.

scholarly journals Magnetic properties of the itinerant ferromagnet LaCrGe3 under pressure studied by La139 NMR

2021 ◽  
Vol 103 (17) ◽  
Author(s):  
K. Rana ◽  
H. Kotegawa ◽  
R. R. Ullah ◽  
E. Gati ◽  
S. L. Bud'ko ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Itinerant Ferromagnet

scholarly journals Impact of Thermal Oxidation on Morphological, Structural and Magnetic Properties of Fe-Ni Wire-Like Nanochains

2021 ◽  
Author(s):  
Marcin Krajewski ◽  
Mateusz Tokarczyk ◽  
Sabina Lewińska ◽  
Kamil Bochenek ◽  
Anna Ślawska-Waniewska
Keyword(s):  
Magnetic Properties ◽  
Thermal Oxidation ◽  
Amorphous Material ◽  
Crystalline Material ◽  
Future Application ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Structural And Magnetic Properties ◽  
Source Of Information ◽  
The Magnetic Field

AbstractThis work presents the evolution of morphological, structural and magnetic properties of amorphous Fe-Ni wire-like nanochains caused by thermal oxidation. The initial Fe1−xNix samples (x = 0.75; 0.50; 0.25) were prepared through the magnetic-field-induced synthesis, and then they were heated in dry air at 400 °C and 500 °C. These treatments led to two competing simultaneous processes occurring in the investigated samples, i.e., (i) a conversion of amorphous material into crystalline material, and (ii) their oxidation. Both of them strictly affected the morphological and structural properties of the Fe-Ni nanochains which, in turn, were associated with the amount of iron in material. It was found that the Fe0.75Ni0.25 and Fe0.50Ni0.50 nanochains were covered during thermal treatment by the nanoparticle oxides. This coverage did not constitute a good barrier against oxidation, and these samples became more oxidized than the Fe0.25Ni0.75 sample which was covered by oxide nanosheets and contained additional Ni3B phase. The specific morphological evolutions of the Fe-Ni nanochains also influenced their saturation magnetizations, whereas their coercivities did not vary significantly. The obtained results constitute an important source of information for future application of the thermally treated Fe-Ni nanochains which could be applied in the energy storage devices or catalysis.

scholarly journals Synthesis of Novel Arginine-Based Flame Retardant and Its Application in Lyocell Fabric

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3588
Author(s):  
Jiayi Chen ◽  
Yansong Liu ◽  
Jiayue Zhang ◽  
Yuanlin Ren ◽  
Xiaohui Liu
Keyword(s):  
Fourier Transform ◽  
Heat Release ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Fourier Transform Infrared ◽  
Ftir Analysis ◽  
Excellent Thermal Stability ◽  
X Ray ◽  
Cone Calorimeter Test ◽  
Before And After

Lyocell fabrics are widely applied in textiles, however, its high flammability increases the risk of fire. Therefore, to resolve the issue, a novel biomass-based flame retardant with phosphorus and nitrogen elements was designed and synthesized by the reaction of arginine with phosphoric acid and urea. It was then grafted onto the lyocell fabric by a dip-dry-cure technique to prepare durable flame-retardant lyocell fabric (FR-lyocell). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that the flame retardant was successfully introduced into the lyocell sample. Thermogravimetric (TG) and Raman analyses confirmed that the modified lyocell fabric featured excellent thermal stability and significantly increased char residue. Vertical combustion results indicated that FR-lyocell before and after washing formed a complete and dense char layer. Thermogravimetric Fourier-transform infrared (TG-FTIR) analysis suggested that incombustible substances (such as H2O and CO2) were produced and played a significant fire retarding role in the gas phase. The cone calorimeter test corroborated that the peak of heat release rate (PHRR) and total heat release (THR) declined by 89.4% and 56.4%, respectively. These results indicated that the flame retardancy of the lyocell fabric was observably ameliorated.

scholarly journals Effects of Perpendicular Magnetic Field Annealing on the Structural and Magnetic Properties of [Co/Ni]2/PtMn Thin Films

2021 ◽  
Vol 7 (3) ◽  
pp. 38
Author(s):  
Roshni Yadav ◽  
Chun-Hsien Wu ◽  
I-Fen Huang ◽  
Xu Li ◽  
Te-Ho Wu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Perpendicular Magnetic Field ◽  
Face Centered Cubic ◽  
Lattice Image ◽  
X Ray ◽  
Field Annealing ◽  
Face Centered

In this study, [Co/Ni]2/PtMn thin films with different PtMn thicknesses (2.7 to 32.4 nm) were prepared on Si/SiO2 substrates. The post-deposition perpendicular magnetic field annealing (MFA) processes were carried out to modify the structures and magnetic properties. The MFA process also induced strong interlayer diffusion, rendering a less sharp interface between Co and Ni and PtMn layers. The transmission electron microscopy (TEM) lattice image analysis has shown that the films consisted of face-centered tetragonal (fct) PtMn (ordered by MFA), body-centered cubic (bcc) NiMn (due to intermixing), in addition to face-centered cubic (fcc) Co, Ni, and PtMn phases. The peak shift (2-theta from 39.9° to 40.3°) in X-ray diffraction spectra also confirmed the structural transition from fcc PtMn to fct PtMn after MFA, in agreement with those obtained by lattice images in TEM. The interdiffusion induced by MFA was also evidenced by the depth profile of X-ray photoelectron spectroscopy (XPS). Further, the magnetic properties measured by vibrating sample magnetometry (VSM) have shown an increased coercivity in MFA-treated samples. This is attributed to the presence of ordered fct PtMn, and NiMn phases exchange coupled to the ferromagnetic [Co/Ni]2 layers. The vertical shift (Mshift = −0.03 memu) of the hysteresis loops is ascribed to the pinned spins resulting from perpendicular MFA processes.

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