Structural and Magnetic Properties of XMnSb/PtMnSb Clb Heusler Alloy Superlattices (X=Ni,Cu)

1997 ◽  
Vol 475 ◽  
Author(s):  
J.F. Bobo ◽  
K. Bessho ◽  
F.B. Mancoff ◽  
P.R. Johnson ◽  
M.C. Kautzky ◽  
...  
Keyword(s):  
Easy Axis ◽  
Heusler Alloys ◽  
Single Layer ◽  
Interlayer Coupling ◽  
Perpendicular Anisotropy ◽  
X Ray Diffraction ◽  
Ordered Structures ◽  
X Ray ◽  
Magnetic Easy Axis

ABSTRACTWe have grown superlattices based on the Clb Heusler alloys PtMnSb, CuMnSb and NiMnSb between 200–500°C on A12O3 (0001). X-ray diffraction (XRD) indicates (111) oriented ordered structures for growth at 300°C. Higher deposition temperature leads to interdiffusion, loss of the multilayer structure and appearance of extra phases. Growth at 200°C slightly reduces the intermixing but also reduces the quality of the crystal structure. For PtMnSb/CuMnSb, we found an enhancement of the saturation magnetization compared to equivalent PtMnSb single layer films and a CuMnSb spacer thickness dependence of the squareness of the M(H) 100ps suggestive of interlayer coupling. Short periodicity NiMnSb/PtMnSb superlattices show an in-plane magnetic easy axis, but correction for shape anisotropy indicates a tendency for perpendicular anisotropy.

2D Magnetic Texture Analysis of Co–Cu Films

2017 ◽  
Vol 72 (5) ◽  
pp. 449-455 ◽  
Author(s):  
Mehmet Bayirli ◽  
Oznur Karaagac ◽  
Hakan Kockar ◽  
Mursel Alper
Keyword(s):  
Fourier Series ◽  
Texture Analysis ◽  
Easy Axis ◽  
Hysteresis Loops ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
Magnetic Texture ◽  
X Ray ◽  
Cu Films ◽  
Magnetic Easy Axis

AbstractThe magnetic textures for the produced magnetic materials are important concepts in accordance with technical applications. Therefore, the aim of this article is to determine 2D magnetic textures of electrodeposited Co–Cu films by the measurement of hysteresis loops at the incremented angles. For that, Co–Cu films were deposited with different Co2+ in the electrolyte. In addition, the easy-axis orientation in the films from the squareness values of the angles, Mp(β) obtained by the hysteresis loops have been numerically studied using the Fourier series analysis. The differences observed in the magnetic easy-axis distributions were attributed to changes of the incorporation of Co in the films with the change of Co2+ in the electrolyte. The coefficients of Fourier series (A0 and A2n ) were also computed for 2D films. It is seen that a systematic and small decrease in A0 and an obvious decrease in A2n (n=1) were observed with increasing incorporated Co in the films. Results imply that interactions cause slightly demagnetization effect accordance with higher incorporation of Co in the films. Furthermore, the crystal structure of the Co–Cu films analysed by X-ray diffraction revealed that the films have dominantly face-centred cubic structure. Film contents analysed by energy-dispersive X-ray spectroscopy and film morphologies observed by scanning electron microscope also support the magnetic texture analysis results found by numerical computation.

BARIUM HEXAFERRITE THICK FILMS BY HOT PRESS SINTERING

2010 ◽  
Vol 24 (06) ◽  
pp. 561-566 ◽  
Author(s):  
H. C. JIANG ◽  
W. L. ZHANG ◽  
Y. HE ◽  
B. PENG ◽  
W. X. ZHANG
Keyword(s):  
Easy Axis ◽  
Thick Films ◽  
Barium Hexaferrite ◽  
Film Plane ◽  
Hot Press ◽  
X Ray Diffraction ◽  
X Ray ◽  
Remanence Ratio ◽  
Magnetic Easy Axis ◽  
Hot Press Sintering

BaFe 12 O 19 ferrite thick films were screen-printed and sintered at 1150°C under pressure (hot press sintering). The effects of the hot press sintering on the properties of barium hexaferrite thick films were investigated. The X-ray diffraction pattern shows improvement of the (00l) texture under pressure. The porosity size of the hot press sintering samples decreases obviously and the surface compactness is improved as the pressure is increased. The films are quite anisotropic with magnetic easy axis perpendicular to the film plane. The largest remanence ratio achieved is 0.75 under the highest pressure of 4 MPa.

scholarly journals X-ray diffraction analysis of kaolin M1 and M2 via the Williamson–Hall and Warren–Averbach methods

2021 ◽  
pp. 174751982098472
Author(s):  
Lalmi Khier ◽  
Lakel Abdelghani ◽  
Belahssen Okba ◽  
Djamel Maouche ◽  
Lakel Said
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Low Temperature ◽  
Diffraction Analysis ◽  
Mechanical Resistance ◽  
X Ray Diffraction ◽  
Integral Breadth ◽  
X Ray ◽  
Mullite Phase

Kaolin M1 and M2 studied by X-ray diffraction focus on the mullite phase, which is the main phase present in both products. The Williamson–Hall and Warren–Averbach methods for determining the crystallite size and microstrains of integral breadth β are calculated by the FullProf program. The integral breadth ( β) is a mixture resulting from the microstrains and size effect, so this should be taken into account during the calculation. The Williamson–Hall chart determines whether the sample is affected by grain size or microstrain. It appears very clearly that the principal phase of the various sintered kaolins, mullite, is free from internal microstrains. It is the case of the mixtures fritted at low temperature (1200 °C) during 1 h and also the case of the mixtures of the type chamotte cooks with 1350 °C during very long times (several weeks). This result is very significant as it gives an element of explanation to a very significant quality of mullite: its mechanical resistance during uses at high temperature remains.

Study of the quality of GaAs thin film on Si substrate by X-ray diffraction method

1990 ◽  
Vol 7 (7) ◽  
pp. 308-311
Author(s):  
Li Chaorong ◽  
Mai Zhenhong ◽  
Cui Shufan ◽  
Zhou Junming ◽  
Yutian Wang
Keyword(s):  
Thin Film ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray

scholarly journals High temperature structural study of decagonal Al-Cu-Rh quasicrystal.

2014 ◽  
Vol 70 (a1) ◽  
pp. C94-C94
Author(s):  
Pawel Kuczera ◽  
Walter Steurer
Keyword(s):  
Structural Changes ◽  
Configurational Entropy ◽  
Lattice Vibrations ◽  
X Ray Diffraction ◽  
Stabilization Mechanism ◽  
X Ray ◽  
Comparative Structure ◽  
The Stability

The structure of d(ecagonal)-Al-Cu-Rh has been studied as a function of temperature by in-situ single-crystal X-ray diffraction in order to contribute to the discussion on energy or entropy stabilization of quasicrystals (QC) [1]. The experiments were performed at 293 K, 1223 K, 1153 K, 1083 K, and 1013 K. A common subset of 1460 unique reflections was used for the comparative structure refinements at each temperature. The results obtained for the HT structure refinements of d-Al-Cu-Rh QC seem to contradict a pure phasonic-entropy-based stabilization mechanism [2] for this QC. The trends observed for the ln func(I(T1 )/I(T2 )) vs.|k⊥ |^2 plots indicate that the best on-average quasiperiodic order exists between 1083 K and 1153 K, however, what that actually means is unclear. It could indicate towards a small phasonic contribution to entropy, but such contribution is not seen in the structure refinements. A rough estimation of the hypothetic phason instability temperature shows that it would be kinetically inaccessible and thus the phase transition to a 12 Å low T structure (at ~800 K) is most likely not phason-driven. Except for the obvious increase in the amplitude of the thermal motion, no other significant structural changes, in particular no sources of additional phason-related configurational entropy, were found. All structures are refined to very similar R-values, which proves that the quality of the refinement at each temperature is the same. This suggests, that concerning the stability factors, some QCs could be similar to other HT complex intermetallic phases. The experimental results clearly show that at least the ~4 Å structure of d-Al-Cu-Rh is a HT phase therefore entropy plays an important role in its stabilisation mechanism lowering the free energy. However, the main source of this entropy is probably not related to phason flips, but rather to lattice vibrations, occupational disorder unrelated to phason flips like split positions along the periodic axis.

Crystalline and Electrical Properties of Ferroelectric Silver Niobate-tantalate thin Films

2000 ◽  
Vol 655 ◽  
Author(s):  
Jung-Hyuk Koh ◽  
S.I. Khartsev ◽  
Alex Grishin ◽  
Vladimir Petrovsky
Keyword(s):  
Temperature Stability ◽  
Frequency Dispersion ◽  
Processing Temperature ◽  
High Temperature Stability ◽  
X Ray Diffraction ◽  
Ferroelectric State ◽  
X Ray ◽  
Ferroelectric Hysteresis ◽  
First Time

AbstractFor the first time AgTa0.38Nb0.62O3 (ATN) films have been grown on the La0.7Sr0.3CoO3 (LSCO)/LaAlO3 single crystal as well as onto Pt80Ir20 (PtIr) polycrystalline substrate. Comprehensive X-ray diffraction analyses reveal epitaxial quality of ATN and LSCO films on the LaAlO3(001) substrate, while ATN/PtIr films have been found to be (001) preferentially oriented. Dielectric spectroscopy performed for ATN films and bulk ceramics in a wide temperature range 77 to 420 K shows the structural monoclinic M1-to-monoclinic M2 phase transition occurs in films at the temperature 60 °C lower than in ceramics. The tracing of the ferroelectric hysteresis P-E loops indicates the ferroelectric state in ATN films at temperatures below 125 K and yields remnant polarization of 0.4 μC/cm2 @ 77 K. Weak frequency dispersion, high temperature stability of dielectric properties as well as low processing temperature of 550 °C make ATN films to be attractive for various applications.

Characterization of Natural and Synthesized FeTiO3 Crystals With RBS/PIXE/XRD

1997 ◽  
Vol 07 (03n04) ◽  
pp. 265-275
Author(s):  
R. Q. Zhang ◽  
S. Yamamoto ◽  
Z. N. Dai ◽  
K. Narumi ◽  
A. Miyashita ◽  
...  
Keyword(s):  
Single Crystals ◽  
Ion Beam ◽  
Pressure Control ◽  
Floating Zone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Beam Analysis ◽  
Ppm Level

Natural FeTiO 3 (illuminate) and synthesized FeTiO 3, single crystals were characterized by Rutherford backscattering spectroscopy combined with channeling technique and particle-induced x-ray emission (RBS-C and PIXE). The results obtained by the ion beam analysis were supplemented by the x-ray diffraction analysis to identify the crystallographic phase. Oriented single crystals of synthesized FeTiO 3 were grown under the pressure control of CO 2 and H 2 mixture gas using a single-crystal floating zone technique. The crystal quality of synthesized FeTiO 3 single crystals could be improved by the thermal treatment but the exact pressure control is needed to avoid the precipitation of Fe 2 O 3 even during the annealing procedure. Natural FeTiO 3 contains several kinds of impurities such as Mn , Mg , Na and Si . The synthesized samples contain Al , Si and Na which are around 100 ppm level as impurities. The PBS-C results of the natural sample imply that Mn impurities occupy the Fe sublattice in FeTiO 3 or in mixed phase between ilmenite and hematite.

Epitaxial Growth OF (001)- and (111)-Oriented PTMNSB Films and Multilayers

1995 ◽  
Vol 384 ◽  
Author(s):  
M.C. Kautzky ◽  
B.M. Clemens
Keyword(s):  
Kerr Effect ◽  
Single Phase ◽  
Single Layer ◽  
Film Structure ◽  
Interference Effects ◽  
X Ray Diffraction ◽  
Orientation Relationships ◽  
Rocking Curve ◽  
Large Rotations

ABSTRACTIn this paper we report the successful growth of single-phase epitaxial PtMnSb films and multilayers by dc magnetron cosputtering, both in the (001) orientation on MgO(001) and W(001), and in the (111) orientation on Al2O3 (0001). Single-layer films in the thickness range 50Å≤t≤1000Å were grown and characterized using x-ray diffraction (XRD), magneto-optic Kerr effect (MOKE), and vibrating sample magnetometry (VSM). The in-plane orientation relationships, as determined by asymmetric XRD, were PtMnSb[100]∥MgO[110], PtMnSb[100]∥W[100], and PtMnSb[101∥Al2O3[2110]. The crystalline quality of the films was found to depend strongly upon the substrate, growth temperature, film thickness, and presence of a capping layer, but rocking curve widths of 1° or less were achieved on each substrate. Measurement of the in-plane strain showed that the films were almost entirely relaxed, with strains <1%. In-plane magnetization was observed in all cases, with moments and coercivities in the 400-500 emu/cm3 and 100-200 Oe ranges respectively. Polar Kerr spectra showed large rotations (0.75° - 1.03°), whose peak wavelengths appear to depend on both film structure and optical interference effects.

Strain, Stress, and Magnetic Surfaceanisotropy of Epitaxial FE(110)/MO (110) Multilayers

1993 ◽  
Vol 317 ◽  
Author(s):  
R.M. Osgood ◽  
B.M. Clemens ◽  
R.L. White ◽  
S. Brennan
Keyword(s):  
Strain State ◽  
Single Layer ◽  
Grazing Incidence ◽  
Magnetic Surface ◽  
Stress And Strain ◽  
Surface Anisotropy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plane Direction ◽  
Strain Stress

ABSTRACTGrazing incidence and asymmetric X-ray diffraction were used to measure the stress and strain state of Fe(110)/Mo(110) Multilayers. The highest stress in the Fe constituent of the multilayer was along the [110] in-plane direction and was due to interaction with the substrate. The Magnetic anisotropy of the Fe Multilayer constituent was measured and the magnetic surface anisotropy, which favored in-plane [001] magnetization, was deduced. In contrast, the magnetic surface anisotropy of a single layer of Fe on W preferred in-plane [110] magnetization, in agreement with the Néel Model.

Magnetic Anisotropy in Electrodeposited CO Films and spin-valves on Gaas Substrates

1999 ◽  
Vol 562 ◽  
Author(s):  
K. Attenborough ◽  
M. Cerisier ◽  
H. Boeve ◽  
J. De Boeck ◽  
G. Borghs ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Buffer Layer ◽  
Structural Properties ◽  
Easy Axis ◽  
Spin Valve ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Films ◽  
Gaas Substrates ◽  
Unique Spin

ABSTRACTWe have studied the magnetic and structural properties of thin electrodeposited Co and Cu layers grown directly onto (100) n-GaAs and have investigated the influence of a buffer layer. A dominant fourfold anisotropy with a uniaxial contribution is observed in 10 nm Co electrodeposited films on GaAs. An easy axis is observed in the [001] GaAs direction with two hard axes of differing coercivities parallel to the [011] and [011] directions. For thicker films the easy axes in the [001] direction becomes less pronounced and the fourfold anisotropy becomes less dominant. Co films of similar thicknesses deposited onto an electrodeposited Cu buffer layer were nearly isotropic. From X-ray diffraction 21 nm Co layers on GaAs were found to be hcp with the c-axis tending to be in the plane of the film. The anisotropy is ascribed to the Co/GaAs interface and is held responsible for the unique spin-valve properties seen recently in electrodeposited Co/Cu films.

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