Sn hyperfine field distributions in the Heusler alloys XMnSn and X2MnSn

1981 ◽  
Vol 59 (11) ◽  
pp. 1577-1584 ◽  
Author(s):  
R. A. Dunlap ◽  
R. H. March ◽  
G. Stroink
Keyword(s):  
Hyperfine Field ◽  
Fourier Expansion ◽  
Heusler Alloys ◽  
Expansion Method ◽  
Wide Distribution ◽  
Ordered Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Field Distributions ◽  
Hyperfine Field Distributions

The 119Sn hyperfine field in the Heusler alloys Ir1.07Mn1.07Sn0.86, PtMnSn, Ni2MnSn, Co2MnSn, and Pd2MnSn has been measured using the Mössbauer effect. Hyperfine field distributions were obtained from the Mössbauer spectra via the Fourier expansion method of Window. The spectra of Ni2MnSn, Co2MnSn, and Pd2MnSn showed a well-defined value of the hyperfine field. This indicates a well-ordered structure and is consistent with previous neutron diffraction and NMR measurements on these alloys. The Ir1.07Mn1.07Sn0.86 and PtMnSn spectra, on the other hand, showed a wide distribution of fields, indicating a considerable amount of disorder. The extent and type of disorder, as indicated by X-ray diffraction measurements, are also considered.

Magnetic and chemical ordering in the Heusler system Co2Mn1−xTixSn

1982 ◽  
Vol 60 (6) ◽  
pp. 909-914 ◽  
Author(s):  
R. A. Dunlap ◽  
G. Stroink
Keyword(s):  
Fourier Expansion ◽  
Heusler Alloys ◽  
Expansion Method ◽  
Magnetic Hyperfine ◽  
X Ray Diffraction ◽  
Hyperfine Fields ◽  
Magnetization Measurements ◽  
X Ray ◽  
Chemical Ordering ◽  
Mössbauer Measurements

119Sn Mössbauer effect, magnetization, and X-ray diffraction measurements have been made on the series of Heusler alloys CO2Mn1−xTixSn (0 ≤ x ≤ 1). The Mössbauer measurements are used to obtain the distribution of hyperfine fields by the Fourier expansion method of Window, This distribution is discussed in terms of the state of chemical ordering of the alloys, as indicated by the X-ray measurements. The magnetization measurements are compared with previous results by Webster and Sobezak, and are used to estimate the magnetic hyperfine fields as predicted by the Jena–Geldart theory.

Structure, Magnetic Properties and Hyperfine Parameters of Nd-Substituted Ni-Fe-Ga Heusler Alloys

MRS Advances ◽  
2017 ◽  
Vol 2 (25) ◽  
pp. 1341-1346
Author(s):  
Monica Sorescu ◽  
Felicia Tolea ◽  
Mihaela Valeanu ◽  
Mihaela Sofronie
Keyword(s):  
Melt Spinning ◽  
Magnetic Measurements ◽  
Heusler Alloys ◽  
Hyperfine Magnetic Field ◽  
Rapid Quenching ◽  
Linear Least Squares ◽  
X Ray Diffraction ◽  
Hyperfine Parameters ◽  
X Ray ◽  
Field Distributions

ABSTRACTSamples of Ni57-xNdxFe18Ga25 with x=2 and 4 were prepared in ribbon form by rapid quenching via melt spinning route. The samples were analyzed by X-ray diffraction (XRD), magnetic measurements and Mössbauer spectroscopy, both in the as-quenched form and after thermal annealing at 900 oC for 2 min and 400 °C for 2 hours. For x=2 the Nd atoms are completely dissolved in the Ni-Fe-Ga matrix, while for x=4 the additional occurrence of the secondary 2:17 phase could be resolved. These findings were supported by the analysis of hyperfine magnetic field distributions obtained from the non-linear least-squares fitting of the Mössbauer spectra.

X-ray diffraction and magnetic studies of altered ilmenite and pseudorutile

1980 ◽  
Vol 43 (329) ◽  
pp. 659-663 ◽  
Author(s):  
M. J. Wort ◽  
M. P. Jones
Keyword(s):  
Magnetic Susceptibility ◽  
Western Australia ◽  
Wide Distribution ◽  
Diffraction Spectrum ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Subsequent Work ◽  
Secondary Alteration ◽  
X Ray ◽  
Magnetic Spin

SynopsisIT was not until 1966 that pseudorutile was first defined. Earlier, its X-ray diffraction spectrum had been confused with that of futile and, to a lesser degree, with those of hematite and ilmenite. Subsequent work has shown that pseudorutile has a world-wide distribution in detrital ilmenite-bearing heavy mineral deposits. The present work has confirmed its magnetic susceptibility and density. In addition pseudorutile is shown to be a magnetic spin glass with a peak susceptibility at 23 °K.Altered ilmenites, in which pseudorutile occurs as a secondary alteration product, display a range of chemical composition and magnetic susceptibility. The most highly magnetic fractions are not necessarily those containing the least-altered ilmenite, and in material from Capel, Western Australia, the most highly magnetic fractions were those containing grains of ferrimagnetic ferrian ilmenite.Quantitative X-ray diffraction has shown that West Australian altered ilmenite contains significant amounts of amorphous ilmenite, pseudorutile, and rutile. The magnetic susceptibility of paramagnetic fractions of altered ilmenite from Capel, Western Australia, can be calculated from normative compositions based on chemical analyses.

Mechanical Properties and Ordered Structure of Bacterial Poly(3-Hydroxybutyrate-Co-3-Hydroxyhexanoate) Fibers Stretched after Isothermal Crystallization near Tg

2011 ◽  
Vol 284-286 ◽  
pp. 1774-1777 ◽  
Author(s):  
Chang Kun Ding ◽  
Bo Wen Cheng ◽  
Qiong Wu
Keyword(s):  
Isothermal Crystallization ◽  
Melt Spinning ◽  
Room Temperature ◽  
Low Molecular Weight ◽  
Ordered Structure ◽  
X Ray Diffraction ◽  
Recombinant Bacteria ◽  
X Ray ◽  
Flexible Fibers ◽  
One Step

Biodegradable fibers of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) were prepared by melt spinning, followed by one-step-drawing with small crystal nuclei grown after isothermal crystallization near the glass transition temperature (Tg) and annealing at room temperature under tension. This new drawing technique is a very attractive method for obtaining flexible fibers from low-molecular-weight biopolyesters produced by recombinant bacteria. The ordered structure of PHBHHx fibers was investigated by tensile measurement, scanning electron microscopy, and wide-angle X-ray diffraction (WAXD). The tensile strength of 10 times one-step-drawn fiber after isothermal crystallization increased to 100 MPa. The WAXD profiles of PHBHHx fibers showed sharp reflections corresponding to highly oriented α-form (21helix conformation) crystal.

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