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.

Influence of Gd Addition on the Structure and Capability of Ni-Mn-In Metamagnetic Shape Memory Alloys

2012 ◽  
Vol 535-537 ◽  
pp. 950-953
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Zhi Jian Duan ◽  
Jian Jun Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Transition Temperature ◽  
Martensitic Transformation ◽  
Room Temperature ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It is Observed through the experiment: the addition of Gd enhances martensite transition temperature;X-ray diffraction analysis of experimental alloys is revealed that to the mixture is martensite and austenite at room temperature; content of Gd is not proportional to the improvement of magnetic property.

scholarly journals Martensitic Transformation and Crystalline Structure of Ni50Mn50−xSnx Melt-Spun Heusler Alloys

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 853
Author(s):  
Rim Ameur ◽  
Mahmoud Chemingui ◽  
Tarek Bachaga ◽  
Lluisa Escoda ◽  
Mohamed Khitouni ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Room Temperature ◽  
Solidification Rate ◽  
Heusler Alloys ◽  
X Ray Diffraction ◽  
Key Factors ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Characteristic Temperatures ◽  
Melt Spun

The structure and thermal behavior are key factors that influence the functional response of Ni–Mn–Sn alloys. The present study reports the production as well as the structure and thermal analysis of melt-spun (solidification rate: 40 ms−1) Ni50 Mn50−xSnx (x = 10, 11, 12 and 13 at.%) alloys. X-ray diffraction measurements were performed at room temperature. The austenite state has an L21 structure, whereas the structure of the martensite is 7M or 10M (depending on the Sn/Mn percentage). Furthermore, the structural martensitic transformation was detected by differential scanning calorimetry (DSC). As expected, upon increasing the Sn content, the characteristic temperatures also increase. The same tendency is detected in the thermodynamic parameters (entropy and enthalpy). The e/a control allows the development production of alloys with a transformation close to room temperature.

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.

scholarly journals Characterization of steel billet scales generated during the continuous casting process in SIDERPERU steel plant

2021 ◽  
Vol 242 (1) ◽  
Author(s):  
L. E. Borja-Castro ◽  
A. Bustamante Dominguez ◽  
M. I. Valerio-Cuadros ◽  
R. A. Valencia-Bedregal ◽  
H. A. Cabrera-Tinoco ◽  
...  
Keyword(s):  
Room Temperature ◽  
Steel Production ◽  
Casting Process ◽  
Steel Plant ◽  
X Ray Diffraction ◽  
Hyperfine Fields ◽  
X Ray ◽  
Billet Surface ◽  
T Values

AbstractTons of waste is produced during iron steel’s industrial production, creating environmental pollution. This work aims to characterize the steel scale formed on the billet surface during the last step of steel production in the SIDERPERU steel plant. Scanning Electron Microscopy (SEM) shows stacked layers one above the other on steel billets scales surface. Energy Dispersive X-ray (EDX) and X-ray Fluorescence (XRF) reveal the high content of Fe and O, with Ca, Si, Mn, and Cr as minority elemental compounds. X-ray Diffraction (XRD) shows FeO, α-Fe2O3 and Fe3O4 as crystallographic phases. Magnetometry reveals Verwey transition and paramagnetic signals that screen the Morin transition. Mössbauer Spectroscopy at room temperature displays magnetic and non-magnetic parts. The non-magnetic part has the hyperfine parameters corresponding to predominant nonstoichiometric wustite. Octahedral (Fe+2/Fe3+) and tetrahedral Fe+3 hyperfine fields of 46.0 and 49.4 T values respectively are associated to nonstoichiometric magnetite and another sextet with a hyperfine field of 52.0 T is related to hematite.

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%.

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