Granular Structure and Magnetic Properties of FePt/C Films

2005 ◽  
Vol 475-479 ◽  
pp. 3729-3732
Author(s):  
Cong Mian Zhen ◽  
Xiao Xia Zhai ◽  
Chengfu Pan ◽  
Xiangfu Nie
Keyword(s):  
Room Temperature ◽  
Magnetic Measurements ◽  
Carbon Layer ◽  
Fept Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
L10 Structure ◽  
Probe Microscope ◽  
Higher Temperature ◽  
20 Nm

FePt/C mutilayer films were successfully prepared by using RF and DC magnetron sputtering system. FePt nanoparticles embedded in a C matrix were formed by consequently annealing. X-ray diffraction (XRD) results show the degree of atomic ordering of the L10 structure increases with higher temperature annealing. Room temperature magnetic measurements reveal that in-plane coercivity HC, and squareness Mr/MS depend on the thickness of carbon layer. Relatively High HC (3245.1Oe) and squareness (0.67) were obtained when the thickness of C layer is 2.0 nm. The carbon layer not only isolates the FePt grain, but also suppresses the growth of fct FePt grains. When the thickness of carbon layer is 2.0 nm, the FePt grain size decreases down to ~20 nm measured by Scan Probe Microscope (SPM). Interactions between particles can be tuned to near zero when we select the proper thickness of C layer.

scholarly journals Влияние Cr и Ni на формирование фаз в механосинтезированном нанокомпозите на основе Fe-=SUB=-75-=/SUB=-C-=SUB=-25-=/SUB=-

2020 ◽  
Vol 90 (5) ◽  
pp. 787
Author(s):  
А.А. Чулкина ◽  
А.И. Ульянов ◽  
В.А. Волков ◽  
А.Л. Ульянов ◽  
А.В. Загайнов
Keyword(s):  
Curie Temperature ◽  
Amorphous Phase ◽  
Annealing Temperature ◽  
Magnetic Measurements ◽  
Nickel Content ◽  
X Ray Diffraction ◽  
Mechanical Synthesis ◽  
X Ray ◽  
Higher Temperature ◽  
Two Phases

X-ray diffraction, Mossbauer spectroscopy, and magnetic measurements have been used to study the phase formation and doping during mechanical synthesis (MS) and subsequent annealing of the alloy (Fe0.80Cr0.05Ni0.15)75C25. It has been shown that, after MS, the nanocomposite contains mainly two phases – an amorphous phase and cementite A. During annealing, as a result of crystallization of the amorphous phase, cementite B is formed, in which contains more nickel than in the mechanically synthesized cementite A. As the annealing temperature increases, austenite, which is inhomogeneous in nickel content, is formed. The Curie temperature of this austenite reaches 500 °C. It has been determined that cementite in the mechanosynthesized nanocomposite (Fe,Cr,Ni)75C25 has a higher temperature stabilitythan that in a MS composite (Fe,Ni)75C25.

Synthesis, Crystal Structure and Magnetic Properties of a Copper(II) p-Formylbenzoate Complex

2012 ◽  
Vol 67 (11) ◽  
pp. 1185-1190 ◽  
Author(s):  
Jin-Li Qi ◽  
Wei Xu ◽  
Yue-Qing Zheng
Keyword(s):  
Room Temperature ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
Complex Molecules ◽  
Triclinic Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Ferromagnetic Interactions ◽  
Aqueous Conditions ◽  
Discrete Complex

A new Cu(II) complex was prepared at room temperature from the reaction of p-formylbenzoic acid, phenanthroline, CuCl2⋅2H2O, and NaOH under ethanolic aqueous conditions. The complex has been characterized by X-ray diffraction, IR spectroscopy, TG-DTA analyses, and magnetic measurements. Single-crystal X-ray diffraction analysis indicated that the complex crystallizes in the triclinic space group P1̄ with the cell dimensions a=7.875(2), b=10.724(2), c=15.317(3) Å , α =102.65(3), β =93.71(3), γ =107:64(3)°. The Cu atoms are in the environment of distorted CuN2O3 tetragonal pyramids. These discrete complex molecules are packed through intermolecular π...π-stacking interactions and C-H...O hydrogen bonds forming a supramolecular structure. The title complex obeys the Curie-Weiss law with a Curie constant C=0:53 cm3 K mol-1 and a Weiss constant θ = -0:27 K. The shape of the xmT curve is characteristic of weak ferromagnetic interactions between the Cu(II) centers from 300 to 7 K, while there are weak antiferromagnetic interactions below 7 K.

Effect of Deposition Temperature on the Structure and Mechanical Properties of Ti-6Al-4V Film

2013 ◽  
Vol 749 ◽  
pp. 643-647 ◽  
Author(s):  
Lei Li ◽  
Ya Feng Lu ◽  
Wen Xue Li ◽  
Li Ying Zeng ◽  
Yi Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Elastic Moduli ◽  
Preferred Orientation ◽  
Nanoindentation Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phase Direction ◽  
Higher Temperature ◽  
Substrate Temperatures

Ti-6Al-4V films were deposited by direct-current magnetron sputtering at different substrate temperatures. The structure and the surface morphology of the films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The hardness and elastic moduli of Ti-6Al-4V films were measured by nanoindentation test. The results showed that the phase direction of the films deposited at room temperature was (102) orientation, and turned to almost complete (002) preferred orientation at 300°C. For a higher temperature of 500°C, the preferred orientation of the film disappeared and presented a random grain orientation. The hardness and elastic moduli of Ti-6Al-4V films obviously showed the dependence on the temperature. The relationships among temperature, microstructure and mechanical properties of Ti-6Al-4V films were discussed in this paper.

Al2O3 as a Transition Layer for GaN and InGaN Growth on ZnO by MOCVD

2009 ◽  
Vol 1201 ◽  
Author(s):  
Nola Li ◽  
Shen-Jie Wang ◽  
William E. Fenwick ◽  
Andrew Melton ◽  
Chung-Lung Huang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Chemical Vapor ◽  
Shallow Donor ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
X Ray Diffraction ◽  
Edge Emission ◽  
X Ray ◽  
20 Nm ◽  
Related Level

AbstractGaN and InGaN layers were grown on annealed 20 and 50nm Al2O3/ZnO substrates by metalorganic chemical vapor deposition (MOCVD). GaN was only observed by high resolution x-ray diffraction (HRXRD) on 20 nm Al2O3/ZnO substrates. Room temperature photoluminescence (RT-PL) showed the red shift of the GaN near band-edge emission, which might be from oxygen incorporation forming a shallow donor-related level in GaN. HRXRD measurements revealed that (0002) InGaN layers were also successfully grown on 20nm Al2O3/ZnO substrates. In addition, thick InGaN layers (∼200-300nm) were successfully grown on Al2O3/ZnO and bare ZnO substrates. These results are significant as previous studies showed decomposition of the layer at InGaN thicknesses of 100nm or less.

Structural, Magnetic, and Electrical Properties of BiFe1-xMnxO3 Thin Films

2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Ion Concentration ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Sol Gel Process

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.

scholarly journals Synthesis, characterization, electrochemical studies and X-ray structures of mixed-ligand polypyridyl copper(II) complexes with the acetate

2016 ◽  
Vol 81 (11) ◽  
pp. 1251-1262 ◽  
Author(s):  
Oluwafunmilayo Adekunle ◽  
Ray Butcher ◽  
Oladapo Bakare ◽  
Olusegun Odunola
Keyword(s):  
Room Temperature ◽  
Magnetic Measurements ◽  
Magnetic Moments ◽  
Copper Ion ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Elemental Analyses ◽  
Structural Details ◽  
Uv Visible

[Cu(phen)2(CH3COO)](ClO4).2H2O (1) and [Cu(bipy)2(CH3COO)]-(ClO4).H2O (2) {phen = 1,10-phenanthroline, bipy = 2,2?-bipyridine}were synthesized and characterized. The complexes were characterized by employying elemental analyses, infrared and UV-Visible spectroscopy, room temperature magnetic measurements and the crystal structures elucidated using X-ray diffraction experiment. The redox properties of the complexes were also investigated. Both structures have a square pyramidal CuN4O chromophore which exhibit significant distortions due to long Cu-O [2.217(3) ? for (1) and 2.179 (1) for (2)] and Cu-N [2.631(2) ? for (1) and 2.714(1) ? for (2)] bonds. This distortion if further shown by the O-Cu-N bond angles [147.71(8) o for (1) and 153.40(5) o for (2)]. The elemental analyses further support the structural details unveiled by the single crystal X-ray diffraction analysis. The infrared spectra shows the acetate vibrational frequencies at 1587 cm-1,1428 cm-1, 1314 cm-1 for (1) and 1571 cm-1, 1441 cm-1, 1319c m-1 for (2) and the perchlo-rate bands at 1059 cm-1, 720 cm-1 (1) and 1080 cm-1,768 cm-1 (2). The broad d-d bands for the copper ion at 14,514 cm-1(1) and 14,535 cm-1(2) support the adoption of square pyramid geometries. The magnetic moments for the two complexes are 1.83 B.M for (1) and 1.72 B.M for (2). The peak to peak values of the two complexes show that the electrode reactions are quasi-reversibile with ?Ep = 0.023V (1) and 0.025V for (2). In both structures, there are ?-? intermolecular interactions in addition to hydrogen bonding between the units.

Radikal-markierte Metallocene (M = Fe, Co). Metallocenylen verbrückte Bis(3-imidazolin-l-oxyle) / Radical Labeled M etallocenes (M = Fe, Co). M etallocenylene B ridged B is(3-im idazolin-l-oxyls)

2001 ◽  
Vol 56 (7) ◽  
pp. 563-570
Author(s):  
Harald Dialer ◽  
Kurt Polbom ◽  
Wolfgang Beck
Keyword(s):  
Charge Transfer ◽  
Radical Anion ◽  
Room Temperature ◽  
Lithium Salt ◽  
Charge Transfer Complex ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Charge ◽  
Different Sources

Abstract Radical Labeled M etallocenes (M = Fe, Co). M etallocenylene B ridged B is(3-im idazolin-l-oxyls) The addition of the lithium salt of the silyl protected hydroxylamine 1-hydroxy-2,2,4,5,5-pentamethyl-3-imidazoline (1) to 6 ,6 -dimethylfulvalene gives the lithium cyclopentadienide 2 from which the 1,1 '-substituted ferrocene and cobaltocinium derivatives 3 and 4 were obtained. Deprotection and oxidation of 3 and 4 afford the metallocenylene bridged bis(3-imidazolin-l-oxyls) 5 and 7. The ferrocene bridged diradical 5 forms with DDQ a charge transfer complex 8 . The complexes 5 and 7 were characterized by X-ray diffraction and by their EPR spectra. Magnetic measurements show at room temperature two independent spins for 5 and 7 and four unpaired electrons for 8 , the latter arising from three different sources [Fe(III) low spin d5, two nitroxides and DDQ- radical anion].

scholarly journals Synthesis, Characterization and Antitumour Activity of Metal Complexes of 5-Carboxy-2-Thiouracil

1998 ◽  
Vol 5 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Udai P. Singh ◽  
Sudha Singh ◽  
Sukh Mahendra Singh
Keyword(s):  
Metal Complexes ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Antitumour Activity ◽  
Tumour Cells ◽  
Sarcoma 180 ◽  
X Ray Diffraction ◽  
X Ray

Metal complexes of 5-carboxy-2-thiouracil with Mn(ll), Co(ll), Ni(ll), Cu(ll), Zn(ll) and Cd(ll) ions were synthesized, characterized, and subjected to a screening system for evaluation of antitumour activity against Sarcoma-180 (S-180) tumour cells. The complexes were characterized by elemental analysis, infrared, electronic spectra, room temperature magnetic measurements and powder X-ray diffraction. The antitumour activity results indicate that some complexes have antitumour activity both in vivo and in vitro against S-180 tumour cells.

Intermetallic Hydrides Based on (Zr-Ti)(Fe-Cr)2 Type of Compounds

2006 ◽  
Vol 514-516 ◽  
pp. 666-671 ◽  
Author(s):  
Sofoklis S. Makridis ◽  
C. Christodoulou ◽  
Mary Konstantakou ◽  
Th.A. Steriotis ◽  
M. Daniil ◽  
...  
Keyword(s):  
Hydrogen Pressure ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Paramagnetic Behaviour ◽  
Diffraction Patterns ◽  
Microstructural Studies ◽  
Dominant Phase

In this work, the (Zr-Ti)(Fe-Cr)2 based compounds have been synthesized while charging-discharging hydrogen ability has been examined. Relatively low hydrogen pressure has been used for the hydrogenation of the samples. After following the discharging procedure, a high desorbed amount of hydrogen ~180 (ml of H2)/(gr of the alloy) has been measured on the first 15 min by using a volumetric device. The crystal structure has been analyzed by means of x-ray diffraction (XRD) while a Rietveld analysis has been performed on the x-ray diffraction patterns and the characteristic MgZn2 type of structure has found to be the dominant phase in both compounds. The scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDX) have been used for microstructural studies and quantitative analysis, respectively. Magnetic measurements have been performed on the samples and a paramagnetic behaviour has found to be at room temperature.

Isothermal Mechanical Spectroscopy in Equiatomic CuZr Alloy

2012 ◽  
Vol 184 ◽  
pp. 251-256
Author(s):  
D. Belamri ◽  
Veronique Pelosin ◽  
S. Belhas ◽  
Andre Rivière
Keyword(s):  
Room Temperature ◽  
Cubic Phase ◽  
Diffraction Spectrum ◽  
X Ray Diffraction ◽  
Mechanical Spectroscopy ◽  
X Ray ◽  
Different Temperatures ◽  
Measurement Experiment ◽  
Higher Temperature ◽  
Two Peaks

An equiatomic CuZr alloy quenched from 1073 K was studied by isothermal mechanical spectroscopy and X-Ray diffraction. Experiments were performed using a very large frequency range (10-4Hz – 50 Hz) at different temperatures. For each temperature of measurement, experiment started after complete microstructure stabilization of the sample. At room temperature, the X–Ray diffraction spectrum shows that there are two CuZr monoclinic phases as a consequence of a martensitic transformation. These structures are characterized by the existence of twinning defects for the first one and a high dislocation density for the other. Both monoclinic phases disappear at higher temperatures and first transform into the cubic CuZr phase, then this cubic phase transforms into Cu10Zr7and CuZr2phases above 763 K. Internal friction spectra exhibit two relaxation peaks (P1, P2), at low and high temperatures, respectively. After rapid cooling of the sample from 1273 K, the first peak P1appears from room temperature and disappears after annealing above 673 K. The P2peak appears at about 800 K and increases for measurements at higher temperature up to 880 K. This temperature range corresponds with the existence of both Cu10Zr7and CuZr2phases. These two peaks are associated with a relaxation linked to the dislocation microstructure in the two CuZr monoclinic phases for P1 and in the Cu10Zr7and CuZr2phases for P2.

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