MÖSSBAUER MEASUREMENTS ON Hg-Pt-ALLOYS USING THE 158 keV TRANSITION IN 199Hg

1976 ◽  
Vol 37 (C6) ◽  
pp. C6-697-C6-701
Author(s):  
W. WURTINGER
Keyword(s):  
Mössbauer Measurements ◽  
Pt Alloys

A Metastable Crystalline Phase Coexisted with the Decagonal Quasicrystals in Rapidly Solidified Al-Ir Al-Pd and Al-Pt Alloys

1990 ◽  
Vol 48 (1) ◽  
pp. 572-573
Author(s):  
Wang Rong ◽  
Ma Lina ◽  
K.H. Kuo
Keyword(s):  
Metastable Phase ◽  
Hexagonal Phase ◽  
Icosahedral Quasicrystal ◽  
Decagonal Quasicrystal ◽  
Decagonal Phase ◽  
Decagonal Quasicrystals ◽  
Pt Alloy ◽  
Pt Alloys ◽  
Diffraction Patterns ◽  
Rapidly Solidified

Up to now, decagonal quasicrystals have been found in the alloys of whole Al-Pt group metals [1,2]. The present paper is concerned with the TEM study of a hitherto unreported hexagonal phase in rapidly solidified Al-Ir, Al-Pd and Al-Pt alloys.The ribbons of Al5Ir, Al5Pd and Al5Pt were obtained by spun-quenching. Specimens cut from the ribbons were ion thinned and examined in a JEM 100CX electron microscope. In both rapidly solidified Al5Ir and Al5Pd alloys, the decagonal quasicrystal, with rosette or dendritic morphologies can be easily identified by its electron diffraction patterns(EDPs). The EDPs of the decagonal phase for the two alloys are quite similar. However, the existance of decagonal quasicrystal in the Al-Pt alloy has not been verified by our TEM study. It is probably for the reason that the cooling rate is not great enough for the Al5Pt alloy to form the decagonal phase. During the TEM study, a metastable hexagonal phase has been observed in the Al5Ir, Al5Pd and Al5Pt alloys. The lattic parameters calculated from the X-ray powder data of this phase are a=1.229 and c=2.647nm(Al-Pd) and a=1.231 and c=2.623nm(Al-Ir). The composition of this phase was determined by EDS analysis as Al4(Ir, Pd or Pt). It coexists with the decagonal phase in the alloys and transformed to other stable crystalline phases on heating to high temperature. A comparison between the EDPs of the hexagonal and the decagonal phase are shown in Fig.l. Fig. 1(a) is the EDPs of the decagonal phase in various orientions and the EDPs of the hexagonal phase are shown in Fig.1(b), in a similar arrangement as Fig.1(a). It can be clearly seen that the EDPs of the hexagonal phase, especially the distribution of strong spots, are quite similar to their partners of the decagonal quasicrystal in Fig.1(a). All the angles, shown in Fig.l, between two corresponding EDPs are very close to each other. All of these seem strongly to point out that a close structural relationshipexists between these two phases:[110]//d10 [001]//d2(D) //d2 (P)The structure of α-AlFeSi is well known [3] and the 54-atom Mackay icosahedron with double icosahedral shells in the α-AlFeSi structure [4] have been used to model the icosahedral quasicrystal structure. Fig.2(a) and (b) show, respectively, the [110] and [001] projections of the crystal structure of α- AlFeSi, and decagon-pentagons can easily be identified in the former and hexagons in the latter. In addition, the optical transforms of these projections show clearly decagons and hexagons of strong spots, quite similar to those in [110] and [001] EDPs in Fig.1(b). This not only proves the Al(Ir, Pt, Pd) metastable phase being icostructural with the α-AlFeSi phase but also explains the orientation relationship mentioned above.

Magnetic Interactions In YbBa 2Cu 3O x (x = 7.0, 6.0) From 170Yb 3+ Mössbauer Measurements

1995 ◽  
Vol 5 (4) ◽  
pp. 501-515 ◽  
Author(s):  
J. A. Hodges ◽  
P. Bonville ◽  
P. Imbert ◽  
A. Pinatel-Phillipot
Keyword(s):  
Magnetic Interactions ◽  
Mössbauer Measurements

scholarly journals Investigation of Polyol Process for the Synthesis of Highly Pure BiFeO3 Ovoid-Like Shape Nanostructured Powders

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 26 ◽  
Author(s):  
Manel Missaoui ◽  
Sandrine Coste ◽  
Maud Barré ◽  
Anthony Rousseau ◽  
Yaovi Gagou ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
High Purity ◽  
Average Crystallite Size ◽  
Polyol Process ◽  
Pure Bifeo3 ◽  
Optimum Parameters ◽  
Mössbauer Measurements ◽  
Synthesis Protocol ◽  
Nanostructured Powders

Exclusive and unprecedented interest was accorded in this paper to the synthesis of BiFeO3 nanopowders by the polyol process. The synthesis protocol was explored and adjusted to control the purity and the grain size of the final product. The optimum parameters were carefully established and an average crystallite size of about 40 nm was obtained. XRD and Mössbauer measurements proved the high purity of the synthesized nanostructurated powders and confirmed the persistence of the rhombohedral R3c symmetry. The first studies on the magnetic properties show a noticeable widening of the hysteresis loop despite the remaining cycloidal magnetic structure, promoting the enhancement of the ferromagnetic order and consequently the magnetoelectric coupling compared to micrometric size powders.

Estimation of the exchange constants in the Fe sublattice of the Y2Fe17 and Y2Fe17N3−δ compounds from the analysis of Mössbauer measurements

1994 ◽  
Vol 130 (1-3) ◽  
pp. 57-62 ◽  
Author(s):  
M.S. Anagnostou ◽  
I. Panagiotopoulos ◽  
A. Kostikas ◽  
D. Niarchos ◽  
G. Zouganelis
Keyword(s):  
Mössbauer Measurements ◽  
Exchange Constants

Influence of composition and order on the magnetism of Fe–Pt alloys: Neutron powder diffraction and theory

2006 ◽  
Vol 89 (3) ◽  
pp. 032506 ◽  
Author(s):  
Julia Lyubina ◽  
Ingo Opahle ◽  
Manuel Richter ◽  
Oliver Gutfleisch ◽  
Karl-Hartmut Müller ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Pt Alloys

Host–guest interaction and dynamics of haloferrocenes enclathrated in deoxycholic acid as inferred from 57Fe Mössbauer measurements

Polyhedron ◽  
2000 ◽  
Vol 19 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Satoru Nakashima ◽  
Naoki Ichikawa ◽  
Hiroaki Komatsu ◽  
Koji Yamada ◽  
Tsutomu Okuda
Keyword(s):  
Deoxycholic Acid ◽  
57Fe Mössbauer ◽  
Mössbauer Measurements

A 19F, 119Sn nuclear magnetic resonance and 119Sn Mössbauer study of the SnF2–MF–H2O system

1984 ◽  
Vol 62 (3) ◽  
pp. 591-595 ◽  
Author(s):  
Thomas Birchall ◽  
Georges Dénès
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Spectroscopic Data ◽  
Dominant Species ◽  
Mössbauer Study ◽  
Frozen Solution ◽  
Nmr Data ◽  
Mössbauer Measurements ◽  
Mössbauer Parameters ◽  
High Concentrations ◽  
Frozen Solutions

19F and 119Sn nmr spectroscopy has been used to study the SnF2–MF–H2O (M = Li+, Na+, K+, Rb+, Cs+, and [NH4]+) system. The nmr data have been supplemented by frozen solution 119Sn Mössbauer measurements. The evidence suggests that the dominant species in the SnF2–H2O system is a hydrated stannous fluoride, probably SnF2•H2O having Mössbauer parameters of δ = 3.46 mm s−1 and Δ = 1.70 mm s−1. When F− is added to these solutions rapid F− exchange occurs with the hydrated SnF2 and the dominant species becomes [SnF3]−. The 119Sn nmr chemical shift of [SnF3]− is ~ −700 ppm from (CH3)4Sn. The 119Sn Mössbauer parameters for frozen solutions of [SnF3]− are δ = ~ 3.1 mm s−1 Δ = 1.9 mm s−1. These spectroscopic data are cation dependent. We could find no strong evidence for high concentrations of [Sn2F5]− in any of these solutions.

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