Synthesis of Ferromagnetic Germanides in 40Ge/60Mn Films: Magnetic and Structural Properties

2014 ◽  
Vol 215 ◽  
pp. 167-172
Author(s):  
Victor G. Myagkov ◽  
A.A. Matsunin ◽  
Y.L. Mikhlin ◽  
Victor S. Zhigalov ◽  
Liudmila E. Bykova ◽  
...  
Keyword(s):  
Solid State ◽  
Curie Temperature ◽  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Atomic Ratio ◽  
Photoelectron Spectra ◽  
Solid State Reactions ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray

Solid-state reactions between Ge and Mn films are systematically examined using X-ray diffraction, photoelectron spectroscopy and magnetic measurements. The films have a nominal atomic ratio Ge:Mn = 40:60 and are investigated at temperatures from 50 to 500 °С. It is established that after annealing at ~120 °С, the ferromagnetic Mn5Ge3 phase is the first phase to form at the 40Ge/60Mn interface. Increasing the annealing temperature to 500 °С leads to the formation of the ferromagnetic phase with a Curie temperature TC ~ 360 K and magnetization MS ~ 140-200 emu/cc at room temperature. Analysis of X-ray diffraction patterns and the photoelectron spectra suggests that the increased Curie temperature and magnetization are related to the migration of C and O atoms into the Mn5Ge3 lattice and the formation of the Nowotny phase Mn5Ge3СxOy. The initiation temperature (~120 °С) of the Mn5Ge3 phase is the same both for solid-state reactions in Ge/Mn films, as well as for phase separation in GexMn1-x diluted semiconductors. We conclude that the synthesis of the Mn5Ge3 phase is the moving force for the spinodal decomposition of the GexMn1-x diluted semiconductors.

Magnetic and Structural Properties of Nanocomposite ZnO-Fe3O4 Films Prepared by Solid-State Synthesis

2014 ◽  
Vol 215 ◽  
pp. 158-162
Author(s):  
Liudmila E. Bykova ◽  
V.G. Myagkov ◽  
I.A. Tambasov ◽  
O.A. Bayukov ◽  
Victor S. Zhigalov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Physical Methods ◽  
X Ray ◽  
Scanning Electron

A simple method for obtaining ZnO-Fe3O4 nanocomposites using solid-state reaction Zn + 3Fe2O3 ZnO + 2Fe3O4 is suggested. An analysis of the characteristics and properties of ZnO-Fe3O4 nanocomposites was carried out by a combination of structural and physical methods (X-ray diffraction, scanning electron microscopy, photoelectron spectroscopy, Mössbauer measurements, X-ray fluorescent analysis, and magnetic measurements). The magnetization of the hybrid ZnO-Fe3O4 films is equal to 440 emu/cm3. The resulting Fe3O4 nanoparticles are surrounded by a ZnO shell and have sizes ranging between 20 and 40 nm.

Fourfold Magnetic Anisotropy of CoPd Alloy, Obtained by Solid State Reactions in Epitaxal Pd/hcp-Сo and Pd/fcc-Co Bilayers

2015 ◽  
Vol 233-234 ◽  
pp. 571-574
Author(s):  
V.G. Myagkov ◽  
L.E. Bykova ◽  
V.S. Zhigalov ◽  
I.A. Tambasov ◽  
G.N. Bondarenko ◽  
...  
Keyword(s):  
Solid State ◽  
Magnetocrystalline Anisotropy ◽  
Magnetic Measurements ◽  
Anisotropy Constant ◽  
Solid State Reactions ◽  
Atomic Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
Disordered Phase

The solid-state reaction between epitaxial hcp-Co (110) and fcc-Co (001) thin films and Pd layers was investigated at annealing temperatures between 250 and 650 °C using X-ray diffraction and magnetic measurements. No significant intermixing of the layers occurs at annealing temperatures below 400 °C. For the atomic composition 1Co:1Pd after annealing at 450 °C the disordered solid solution fcc-CoxPd1-x is formed on the Pd/hcp-Co (110) and Pd/fcc-Co (001) interfaces. Epitaxial relationships CoPd (110)〈-111〉 || MgO(001)〈100〉 and CoPd (001)〈100〉 || MgO(001)〈100〉 between the nucleated disordered phase CoPd and the substrate MgO(001) were determined for Pd/hcp-Co (110) and Pd/fcc-Co (001) bilayers, respectively. The first magnetocrystalline anisotropy constant of the disordered CoPd phase ​​K1CoPd = - (1.8 ± 0.4)·104 J/m3 for the (110) and (001) orientations was obtained.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

scholarly journals Impact of high temperatures on aluminoceladonite studied by Mössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopy

2021 ◽  
Author(s):  
Mariola Kądziołka-Gaweł ◽  
Maria Czaja ◽  
Mateusz Dulski ◽  
Tomasz Krzykawski ◽  
Magdalena Szubka
Keyword(s):  
Photoelectron Spectroscopy ◽  
Integral Intensity ◽  
Photoelectron Spectra ◽  
X Ray Diffraction ◽  
Structural Reorganization ◽  
Oh Groups ◽  
X Ray ◽  
Al Content ◽  
Integral Intensity Ratio ◽  
Higher Temperature

AbstractMössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopies were used to examine the effects of temperature on the structure of two aluminoceladonite samples. The process of oxidation of Fe2+ to Fe3+ ions started at about 350 °C for the sample richer in Al and at 300 °C for the sample somewhat lower Al-content. Mössbauer results show that this process may be associated with dehydroxylation or even initiate it. The first stage of dehydroxylation takes place at a temperature > 350 °C when the adjacent OH groups are replaced with a single residual oxygen atom. Up to ~500 °C, Fe ions do not migrate from cis-octahedra to trans-octahedra sites, but the coordination number of polyhedra changes from six to five. This temperature can be treated as the second stage of dehydroxylation. The temperature dependence on the integral intensity ratio between bands centered at ~590 and 705 cm−1 (I590/I705) clearly reflects the temperature at which six-coordinated polyhedra are transformed into five-coordinated polyhedra. X-ray photoelectron spectra obtained in the region of the Si2p, Al2p, Fe2p, K2p and O1s core levels, highlighted a route to identify the position of Si, Al, K and Fe cations in a structure of layered silicates with temperature. All the measurements show that the sample with a higher aluminum content and a lower iron content in octahedral sites starts to undergo a structural reorganization at a relatively higher temperature than the less aluminum-rich sample does. This suggests that iron may perform an important role in the initiation of the dehydroxylation of aluminoceladonites.

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.

Magnetic cluster developement in In1−x MnxSb semiconductor alloys

Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Lidia Rednic ◽  
Iosif Deac ◽  
Eugen Dorolti ◽  
Marin Coldea ◽  
Vasile Rednic ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Semiconductor Alloys ◽  
X Ray Diffraction ◽  
Magnetic Cluster ◽  
X Ray ◽  
Small Magnetic Field ◽  
Transmission Electron

AbstractX-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and magnetic measurements as a function of applied magnetic field and temperature for In1−x MnxSb (0.05≤x≤0.2) system are reported. Magnetic measurements performed at high and small magnetic field in ZFC and FC indicate the coexistence of ferromagnetic In1−x MnxSb solid solution and two types of magnetic cluster: ferromagnetic MnSb and ferrimagnetic Mn2Sb. XPS valence band and Mn 2p core level spectra have confirmed the presence of MnSb and Mn2Sb phases. TEM images show some manganese antimonide phase microinclusions with dimension between (30–40) nm.

Stoichiometric Controlling of Spark Plasma Sintered Boron-Carbon Ceramics

2009 ◽  
Vol 66 ◽  
pp. 25-28 ◽  
Author(s):  
Song Zhang ◽  
Chuan Bin Wang ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Measurement Data ◽  
Atomic Ratio ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Carbon Ceramic ◽  
Boron Carbon

A group of boron-carbon ceramic material was in-situ synthesized and densified simultaneously via Spark Plasma Sintering (SPS) technique from carbon and boron element powders with different molar ratio. The phase structures of samples with different B/C molar ratio were characterized by X-ray Diffraction (XRD). The B/C atomic ratio of the sintered materials was calculated from X-ray photoelectron spectroscopy (XPS) measurement data. Meanwhile, the chemical analysis (CA) method had also been taken to verify the B/C atomic ratio. Finally, the experience equation had been obtained to control the B/C atomic ratio of sintered samples.

Solid-state reaction of Pt thin film with single-crystal (001) β–SiC

1994 ◽  
Vol 9 (3) ◽  
pp. 648-657 ◽  
Author(s):  
J.S. Chen ◽  
E. Kolawa ◽  
M-A. Nicolet ◽  
R.P. Ruiz ◽  
L. Baud ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Single Crystal ◽  
Atomic Scale ◽  
Solid State Reactions ◽  
Main Reaction ◽  
Main Reaction Product ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Interlayer

Thermally induced solid-state reactions between a 70 nm Pt film and a single-crystal (001) β-SiC substrate at temperatures from 300 °C to 1000 °C for various time durations are investigated by 2 MeV He backscattering spectrometry, x-ray diffraction, secondary ion mass spectrometry, scanning electron microscopy, and cross-sectional transmission electron microscopy. Backscattering spectrometry shows that Pt reacts with SiC at 500 °C. The product phase identified by x-ray diffraction is Pt3Si. At 600–900 °C, the main reaction product is Pt2Si, but the depth distribution of the Pt atoms changes with annealing temperature. When the sample is annealed at 1000 °C, the surface morphology deteriorates with the formation of some dendrite-like hillocks; both Pt2Si and PtSi are detected by x-ray diffraction. Samples annealed at 500–900 °C have a double-layer structure with a silicide surface layer and a carbon-silicide mixed layer below in contact with the substrate. The SiC—Pt interaction is resolved at an atomic scale with high-resolution electron microscopy. It is found that the grains of the sputtered Pt film first align themselves preferentially along an orientation of {111}Pt//{001}SiC without reaction between Pt and SiC. A thin amorphous interlayer then forms at 400 °C. At 450 °C, a new crystalline phase nucleates discretely at the Pt-interlayer interface and projects into or across the amorphous interlayer toward the SiC, while the undisturbed amorphous interlayer between the newly formed crystallites maintains its thickness. These nuclei grow extensively down into the substrate region at 500 °C, and the rest of the Pt film is converted to Pt3Si. Comparison between the thermal reaction of SiC-Pt and that of Si–Pt is discussed.

Structural, dielectric and magnetic properties of Pr-, Tb- and Dy-doped (Bi0.95RE0.05)(Fe0.95Mn0.05)O3 ceramics synthesized by solid-state reaction method

2013 ◽  
Vol 03 (04) ◽  
pp. 1350033 ◽  
Author(s):  
Radheshyam Rai ◽  
Shweta Thakur ◽  
M. A. Valente ◽  
Andrei L. Kholkin
Keyword(s):  
Magnetic Properties ◽  
Solid State ◽  
Solid State Reaction ◽  
Magnetic Measurements ◽  
Ferroelectric Properties ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Ceramic Samples

The multiferroic ( Bi 0.95 RE 0.05)( Fe 0.95 Mn 0.05) O 3 (where RE = Pr , Tb and Dy ) has been synthesized using solid-state reaction technique. Effects of Pr , Tb and Dy substitution on the structure, electrical and ferroelectric properties of ( Bi 0.95 RE 0.05)( Fe 0.95 Mn 0.05) O 3 samples have been studied by performing X-ray diffraction, dielectric measurements and magnetic measurements. The crystal structure of the ceramic samples have a monoclinic phase. The vibrating sample magnetometer (VSM) measurement shows a significant change in the magnetic properties of Pr -, Tb - and Dy -doped ( Bi 0.95 RE 0.05)( Fe 0.95 Mn 0.05) O 3. It is seen that coercive field (Hc) and remanent magnetization (Mr) increases for Pr but decreases for Dy and Tb .

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