Interface and Volume Anisotropy of MBE-Grown Co/Pt (111), (110) and (001) and Sputtered CO/Pt Multilayers

1993 ◽  
Vol 313 ◽  
Author(s):  
D. Weiler ◽  
R.F.C. Farrow ◽  
R.F. Marks ◽  
G.R. Harp ◽  
H. Notarys ◽  
...  
Keyword(s):  
Room Temperature ◽  
Good Accuracy ◽  
Anisotropy Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gaas Substrates ◽  
Plane Anisotropy ◽  
Plane Direction ◽  
Total Average

ABSTRACTA quantitative determination of interface (Ks) and volume anisotropy {?ψ) constants of MBE and sputtered CO/Pt Multilayers is reported. Torque and VSM Magnetometry were used to determine the total average anisotropy and the room temperature magnetization of four different series of films with varying Co thickness and nearly constant Pt thickness. All films were characterized with X-ray diffraction and X-ray fluorescence, allowing the determination of the “Magnetic” volume with good accuracy. Both Ks and Jeff are found to be orientation dependent. We find the following results for MBE films grown on Ag buffered GaAs substrates and highly < 111 > textured films, grown on etched SiNx buffers:(111) Ks = 0.97mJ/m2, Kveff =-0.74MJ/m3 MBE(111) Ks = 0.92mJ/m2, Kveff =-l.lIMJ/m3 sputtered(110) Ks = 0.42mJ/m2, Kveff =-l.95MJ/m3 MBE(001) Ks = 0.59mJ/m2, Kveff =-5.98MJ/m3 MBEThe [110]-oriented MBE films show in addition a large (intrinsic) in-plane anisotropy constant K‖0≃-3MJ/m3 which is found to be independent of the Co thickness. [100] is the easy and [110] the hard in-plane direction.

Determination of the cationic distribution in oxidic thin films by resonant X-ray diffraction: the magnetoelectric compound Ga2−xFexO3

2016 ◽  
Vol 49 (4) ◽  
pp. 1308-1314 ◽  
Author(s):  
Christophe Lefevre ◽  
Alexandre Thomasson ◽  
Francois Roulland ◽  
Vincent Favre-Nicolin ◽  
Yves Joly ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Element Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Site Distribution ◽  
X Ray Scattering ◽  
Cationic Distribution ◽  
Cationic Site

The cationic distribution is decisive for both the magnetic and electric properties of complex oxides. While it can be easily determined in bulk materials using classical methods such as X-ray or neutron diffraction, difficulties arise for thin films owing to the relatively small amount of material to probe. It is shown here that a full determination of the cationic site distribution in thin films is possible through an optimized processing of resonant elastic X-ray scattering experiments. The method is illustrated using gallium ferrite Ga2−xFexO3samples which have been the focus of an increasing number of studies this past decade. They indeed represent an alternative to the, to date, only room-temperature magnetoelectric compound BiFeO3. The methodology can be applied to determine the element distribution over the various crystallographic sites in any crystallized system.

Residual Stress Measurements of 4H-SiC Crystals Using X-Ray Diffraction

2014 ◽  
Vol 778-780 ◽  
pp. 453-456 ◽  
Author(s):  
Masashi Nakabayashi ◽  
Tatsuo Fujimoto ◽  
Hiroshi Tsuge ◽  
Kiyoshi Kojima ◽  
Kozo Abe ◽  
...  
Keyword(s):  
Residual Stress ◽  
Temperature Distribution ◽  
Room Temperature ◽  
Radial Direction ◽  
Large Strain ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plane Direction ◽  
Lateral Temperature

The room temperature residual stress of 4H-SiC wafers has been investigated using a precise X-ray diffraction method. A large strain was observed for the circumferential direction of wafers, more than ten times larger than those measured along the principal plane direction and the radial direction. Optimizing the lateral temperature distribution in growing crystals leads to reduction of residual stress of wafers with high crystal quality.

Computer Capability for the Determination of Polymer Crystallinity by X-Ray Diffraction

1985 ◽  
Vol 29 ◽  
pp. 281-290
Author(s):  
Andrew M. Wims ◽  
Mark E. Myers ◽  
Jack L. Johnson ◽  
Julia M. Carter
Keyword(s):  
Room Temperature ◽  
Physical And Mechanical Properties ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Percent Elongation ◽  
X Ray ◽  
Reinforcing Fillers ◽  
Crystalline Domains ◽  
Polymer Crystallinity

The physical and mechanical properties of many industrially important polymers are profoundly influenced by their degree of crystallinity; such properties include flex modulus, tensile strength, percent elongation, and impact strength. Commonly used polymers influenced by their crystallinity level include polyethlene, polypropylene, polyesters, and nylons. Many of these materials are above their glass transition temperature at room temperature and would be useless were it not for their crystalline phase which typically has a melting point far above room temperature. The crystalline ‘ regions (domains) in these materials are frequently very small, typically in the nanometer range in diameter. These crystalline domains act as reinforcing fillers (in somewhat the same manner as carbon black In rubber) and give strength to the polymer.

Investigation into the Crystal Structure of the Perovskite Lead Hafnate, PbHfO3

1998 ◽  
Vol 54 (1) ◽  
pp. 18-28 ◽  
Author(s):  
D. L. Corker ◽  
A. M. Glazer ◽  
W. Kaminsky ◽  
R. W. Whatmore ◽  
J. Dec ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Room Temperature ◽  
Lead Zirconate ◽  
Crystal Structure Analysis ◽  
Temperature Structure ◽  
X Ray Diffraction ◽  
Neutron Data ◽  
X Ray

The room-temperature crystal structure of the perovskite lead hafnate PbHfO3 is investigated using both low-temperature single crystal X-ray diffraction (Mo Kα radiation, λ = 0.71069 Å) and polycrystalline neutron diffraction (D1A instrument, ILL, λ = 1.90788 Å). Single crystal X-ray data at 100 K: space group Pbam, a = 5.856 (1), b = 11.729 (3), c = 8.212 (2) Å, V = 564.04 Å3 with Z = 8, μ = 97.2 mm−1, F(000) = 1424, final R = 0.038, wR = 0.045 over 439 reflections with F >1.4σ(F). Polycrystalline neutron data at 383 K: a = 5.8582 (3), b = 11.7224 (5), c = 8.2246 (3) Å, V = 564.80 Å3 with χ2 = 1.62. Although lead hafnate has been thought to be isostructural with lead zirconate, no complete structure determination has been reported, as crystal structure analysis in both these materials is not straightforward. One of the main difficulties encountered is the determination of the oxygen positions, as necessary information lies in extremely weak l = 2n + 1 X-ray reflections. To maximize the intensity of these reflections the X-ray data are collected at 100 K with unusually long scans, a procedure which had previously been found successful with lead zirconate. In order to establish that no phase transitions exist between room temperature and 100 K, and hence that the collected X-ray data are relevant to the room-temperature structure, birefringence measurements for both PbZrO3 and PbHfO3 are also reported.

MBE GROWN ZnSSe/ZnMgSSe MQW STRUCTURE FOR BLUE VCSEL

2007 ◽  
Vol 06 (05) ◽  
pp. 407-410 ◽  
Author(s):  
I. P. KAZAKOV ◽  
V. I. KOZLOVSKY ◽  
V. P. MARTOVITSKY ◽  
YA. K. SKASYRSKY ◽  
M. D. TIBERI ◽  
...  
Keyword(s):  
Room Temperature ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Optical Scanning ◽  
Atomic Force ◽  
Gaas Substrates ◽  
Two Phases

ZnSSe / ZnMgSSe MQW structures were grown by molecular beam epitaxy on GaAs substrates. The band gap of ZnMgSSe barriers was approximately 3 eV at room temperature. Cathodoluminescence, X-ray diffraction, optical, scanning electron beam, and atomic force microscopy were all used for structure characterization. Decay of the ZnMgSSe solid solution in at least two phases was observed. Improvement in the quality of the crystal lattice and surface morphology was achieved by mismatching the ZnMgSSe from the GaAs substrate by increasing the lattice period by 0.24%.

Crystal Structure and Magnetic Properties of Novel Compound PrFe8Ga3C

2009 ◽  
Vol 152-153 ◽  
pp. 75-78 ◽  
Author(s):  
V.S. Gaviko ◽  
A.G. Popov ◽  
G.V. Ivanova ◽  
N.V. Mushnikov ◽  
Y.V. Belozerov ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Spontaneous Magnetization ◽  
Anisotropy Constant ◽  
X Ray Diffraction ◽  
Easy Magnetization ◽  
Magnetization Direction ◽  
X Ray ◽  
Powder Samples ◽  
Curie Temperature Tc

We have synthesized a novel intermetallic compound PrFe8Ga3C and studied its structure and magnetic properties. X-ray diffraction analysis revealed that the compound possesses a tetragonal BaCd11-type structure (space group I41/amd). In this structure Ga atoms occupy the same sites as Fe atoms with preferably filling the 4(b) site. Magnetization curves have been measured on the aligned powder samples. Below the Curie temperature TC = 400 K the easy magnetization direction was found to orient within the (100) plane. At 80 K the compound has a spontaneous magnetization of 97 emu/g and anisotropy constant of 4.2107 erg/cm3. At room temperature these values reduce to 78 emu/g and 4.7106 erg/cm3, respectively.

High-precision absolute lattice parameter determination of SrTiO3, DyScO3 and NdGaO3 single crystals

2012 ◽  
Vol 68 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Martin Schmidbauer ◽  
Albert Kwasniewski ◽  
Jutta Schwarzkopf
Keyword(s):  
High Resolution ◽  
High Precision ◽  
Room Temperature ◽  
Systematic Errors ◽  
Lattice Parameter ◽  
Parameter Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Method

The lattice parameters of three perovskite-related oxides have been measured with high precision at room temperature. An accuracy of the order of 10−5 has been achieved by applying a sophisticated high-resolution X-ray diffraction technique which is based on the modified Bond method. The results on cubic SrTiO3 [a = 3.905268 (98) Å], orthorhombic DyScO3 [a = 5.442417 (54), b = 5.719357 (52) and c = 7.904326 (98) Å], and orthorhombic NdGaO3 [a = 5.428410 (54), b = 5.498407 (55) and c = 7.708878 (95) Å] are discussed in view of possible systematic errors as well as non-stoichiometry in the crystals.

UV Photocatalytic Digestion Utilizing TiO2 Nano-Fiber for the Determination of Total Phosphorus

2015 ◽  
Vol 645-646 ◽  
pp. 375-380
Author(s):  
Qiang Zhang ◽  
Jian Hua Tong ◽  
Chao Bian ◽  
Shan Hong Xia
Keyword(s):  
Total Phosphorus ◽  
Room Temperature ◽  
Sodium Tripolyphosphate ◽  
Uv Light ◽  
X Ray Diffraction ◽  
Muffle Furnace ◽  
Digestion Rate ◽  
X Ray ◽  
Nano Fiber

This paper describes the fabrication, characterization and the application of the photocatalytic TiO2nanofiber as the photocatalyst for the digestion of total phosphorus (TP). The nanoTiO2fibers were fabricated by the electro-spinning technique on silicon substrate. Under the conditions of room temperature (25 degrees Celsius) and humidity less than 40%, the TiO2fabricated by the electro-spinning presents a silky coagulation appearance, which can be converted to the nanofiber appearance by annealed in the muffle furnace at 450 degrees Celsius for 10 hours. X-ray diffraction (XRD) examination shows that the silky coagulation can be converted to anatase-type TiO2. The absorbance values of different phosphate concentrations after exposure in UV light at the intensity of 7000μW/cm2were tested in this paper. Sodium tripolyphosphate solutions serve as the water sample of TP, and five standard concentrations (by weight of P) are 0.0mg/L, 1.0mg/L, 2.0mg/L,3.0mg/L and 4.0mg/L, respectively. The digestion rate exhibits satisfied linearity ranges from 0.0mg/L to 4.0mg/L with acceptable linearity R2of calibration curve, in both digestion temperature of 25 degrees Celsius and 50 degrees Celsius.

scholarly journals Determination of hyperfine fields and atomic ordering in NiMnFeGe exhibiting martensitic transformation

Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 127-131 ◽  
Author(s):  
Dariusz Satuła ◽  
Krzysztof Szymański ◽  
Katarzyna Rećko ◽  
Wojciech Olszewski ◽  
Beata Kalska-Szostko
Keyword(s):  
Martensitic Transformation ◽  
Room Temperature ◽  
Paramagnetic State ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Atomic Ordering ◽  
Hyperfine Fields ◽  
X Ray ◽  
Two Phases

Abstract The hyperfine fields and atomic ordering in Ni1−xFexMnGe (x = 0.1, 0.2, 0.3) alloys were investigated using X-ray diffraction and Mössbauer spectroscopy at room temperature. The X-ray diffraction measurements show that the samples with x = 0.2, 0.3 crystallized in the hexagonal Ni2In-type of structure, whereas in the sample with x = 0.1, the coexistence of two phases, Ni2In- and orthorhombic TiNiSi-type of structures, were found. The Mössbauer spectra measured with x = 0.2, 0.3 show three doublets with different values of isomer shift (IS) and quadrupole splitting (QS) related to three different local surroundings of Fe atoms in the hexagonal Ni2In-type structure. It was shown that Fe atoms in the hexagonal Ni2In-type structure of as-cast Ni1−xFexMnGe alloys are preferentially located in Ni sites and small amount of Fe is located in Mn and probably in Ge sites. The spectrum for x = 0.1 shows the doublets in the central part of spectrum and a broad sextet. The doublets originate from the Fe atoms in the paramagnetic state of hexagonal Ni2In-type structure, whereas the sextet results from the Fe atoms in orthorhombic TiNiSi-type structure.

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