Magnetische und Mößbauer-spektroskopische Untersuchungen von zeolithischen Eisenkontakten/ Magnetic and Mössbauer Spectroscopic Studies of Iron-Clusters in Zeolites

1975 ◽  
Vol 30 (12) ◽  
pp. 1627-1632 ◽  
Author(s):  
F. Schmidt ◽  
W. Gunsser ◽  
A. Knappwost
Keyword(s):  
Magnetic Susceptibility ◽  
Temperature Dependence ◽  
Mössbauer Spectra ◽  
Bulk Material ◽  
Spectroscopic Studies ◽  
Ferrous Ions ◽  
Iron Clusters ◽  
Mossbauer Spectra

Abstract Iron clusters have been prepared within zeolite holes by reduction of zeolites containing ferrous ions. The diameter of these particles must therefore be smaller than 13 Å. They are super-paramagnetic and their Mössbauer spectra show no HFS, even at 4 K.The temperature dependence of the magnetic susceptibility of the unreduced zeolites obeys a Curie-Weiss law with peff = 4,54 μB and Θ = 105 K. The Weiss curves of the reduced samples lie distinctly below those of the bulk material.

Dithiolium and diselenolium compounds of the transition metals

1969 ◽  
Vol 22 (1) ◽  
pp. 83 ◽  
Author(s):  
RL Martin ◽  
IM Stewart
Keyword(s):  
Transition Metals ◽  
Temperature Dependence ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra ◽  
First Time

The preparations are reported of an extended series of compounds of the type ML2X4 where M is Mn, Fe, Co, or Ni; X is Cl or Br; and L is analytically identical with dithioacetylacetone. ��� Electronic, infrared, and Mossbauer spectra together with the temperature dependence of the magnetism (80-300�K) of these compounds establish-contrary to previous suggestions in the literature-that they should be properly formulated as tetrahalometallate salts of the 3,5- dimethyl-1,2-dithiolium cation. Simple salts of this cation (such as the iodide) have also been isolated. ��� During the course of this work salts (I- and [CoCl4]2-) of the hitherto unknown 3,5-dimethyl-1,2-diselenolium ion were synthesized and characterized for the first time.

scholarly journals Manganese/Yttrium Codoped Strontium Nanohexaferrites: Evaluation of Magnetic Susceptibility and Mossbauer Spectra

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 24 ◽  
Author(s):  
Munirah Almessiere ◽  
Yassine Slimani ◽  
Hakan Güngüneş ◽  
Abdulhadi Baykal ◽  
S.V. Trukhanov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Mössbauer Spectra ◽  
Ac Susceptibility ◽  
Sol Gel ◽  
Hyperfine Magnetic Field ◽  
Analytical Techniques ◽  
Magnetic Interactions ◽  
Mossbauer Spectra

Manganese (Mn)- and yttrium (Y)-substituted Sr-nanohexaferrites (MYSNHFs) of composition Sr1−xMnxFe12−xYxO19 (with 0.0 ≤ x ≤ 0.5) were prepared by citrate sol-gel autocombustion method. As-prepared MYSNHFs were characterized via diverse analytical techniques to determine the influence of Mn and Y cosubstitution on their microstructures and magnetic properties. 57Fe Mössbauer spectra of the MYSNHFs were used to evaluate the variation in the line width, isomer shift, quadrupole splitting, and hyperfine magnetic field values. It was shown that the dopant ions could preferentially occupy the 12k, 4f2, and 2b sites. Furthermore, the observed shift in the blocking temperatures of the studied MYSNHFs towards lower values with rising Mn2+ and Y3+ contents was attributed to the overall particles size reduction. Meanwhile, the AC susceptibility of the proposed MYSNHFs revealed that the magnetic interactions were weakened with the increase in dopant contents which was ascribed to the replacement of both Sr2+ and Fe3+ ions by the Mn2+ and Y3+ dopants.

Temperature dependence of the Mossbauer spectra of several iron(III) trisdithiocarbamate complexes

1990 ◽  
Vol 2 (50) ◽  
pp. 10091-10107 ◽  
Author(s):  
J M Fiddy ◽  
I Hall ◽  
F Grandjean ◽  
G J Long ◽  
U Russo
Keyword(s):  
Temperature Dependence ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra

The Magnetic Properties and Mössbauer Spectra of Synthetic Samples of Fe3S4

1972 ◽  
Vol 50 (19) ◽  
pp. 2313-2326 ◽  
Author(s):  
M. R. Spender ◽  
J. M. D. Coey ◽  
A. H. Morrish
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
Mössbauer Spectra ◽  
Bulk Material ◽  
Conductivity Measurements ◽  
Intrinsic Properties ◽  
Static Magnetization ◽  
Mossbauer Spectra ◽  
Spin Arrangement ◽  
Applied Fields

The magnetic properties of a number of samples of synthetic Fe3S4 have been studied using both static magnetization measurements and Mössbauer effect spectrometry. The distinction is made between the intrinsic properties of bulk Fe3S4 and observations resulting from superparamagnetic behavior and nonstoichiometry. Mössbauer spectra in applied fields show that the bulk material has a simple Néel ferrimagnetic spin arrangement. The magnetic moment at 4.2 °K is 2.2 ± 0.3 μB per formula unit and the ordering temperature is 606 ± 2 °K. Conductivity measurements indicate semimetallic behavior and two alternative band schemes are proposed to account for this feature and explain the magnetic moment.

Mössbauer studies in transition metal chemistry. IV. Iron(II) complexes of 2-(2'-Pyridyl)benzimidazole

1978 ◽  
Vol 31 (3) ◽  
pp. 487 ◽  
Author(s):  
RL Martin ◽  
IAG Roos ◽  
DML Goodgame ◽  
AASC Machado
Keyword(s):  
Temperature Dependence ◽  
Mössbauer Spectra ◽  
Spin Crossover ◽  
Complex Cation ◽  
Octahedral Symmetry ◽  
Line Lattice ◽  
Metal Chemistry ◽  
Mossbauer Spectra ◽  
Iv Iron ◽  
Mössbauer Parameters

Mossbauer spectra of a number of compounds containing the [Fe(pyb)3]2+ complex cation [pyb, 2-(2'-pyridyl)benzimidazole] confirm that these compounds undergo a change of spin state with temperature consistent with a 5T2-1A1 spin crossover. The nature of the Mossbauer spectra and their temperature-dependence are sensitive to the associated anion and the method of preparation. ��� The temperature-dependence of the Mossbauer parameters has been used to derive information about the distortions from octahedral symmetry and it is concluded that the dimensions of the crystal-line lattice are changing slightly with temperature.

M÷ssbauer studies in transition metal chemistry. I. Compounds of iron with Dithioacetylacetone (Pentane-2,4-dithione)

1971 ◽  
Vol 24 (11) ◽  
pp. 2231 ◽  
Author(s):  
RL Martin ◽  
IAG Roos
Keyword(s):  
Transition Metal ◽  
Temperature Dependence ◽  
Quadrupole Splitting ◽  
Ground State ◽  
Mössbauer Spectra ◽  
Transition Metal Chemistry ◽  
Temperature Dependent ◽  
Orbital Degeneracy ◽  
Metal Chemistry ◽  
Mossbauer Spectra

The temperature dependence of the Mossbauer spectra of some iron- containing compounds of dithioacetylacetone are reported between 4 and 293 K. ��� The quadrupole splitting ΔEq of [Fe(SacSac)3] is larger than usually observed for low-spin six-coordinated iron(III) and is ascribed to the lifting of orbital degeneracy of the 2T2 ground state by small axial and rhombic distortions. ��� The unsubstituted and phenyl-substituted dithiolium salts of [FeCl4]2- exhibit strongly temperature-dependent quadrupole splittings, which arise directly from the lifting of the orbital degeneracy of the 5E ground state due to distortion of the [FeCl4]2- tetrahedron.

Positive Temperature Dependence of Quadrupole Splittings in Mössbauer Spectra of Fe1.33Nb2.67Se10

2002 ◽  
Vol 57 (6-7) ◽  
pp. 627-630 ◽  
Author(s):  
Takashi Suzuki ◽  
Noriaki Okubo
Keyword(s):  
Temperature Dependence ◽  
Mössbauer Effect ◽  
Mössbauer Spectra ◽  
Positive Temperature ◽  
Mossbauer Effect ◽  
Mossbauer Spectra ◽  
Positive Temperature Dependence ◽  
Low Dimensional

The Mössbauer effect in the low-dimensional compound Fe1.33Nb2.67Se10 has been examined between 78 and 414 K. An anusual positive temperature dependence of the quadrupole splittings was found above 250 K. As a possible origin a mechanism due to π bonding is suggested

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