Magnetic susceptibility and magnetic anisotropy studies in some ferric dithiocarbamates exhibiting spin-crossover phenomena

1978 ◽  
Vol 17 (3) ◽  
pp. 543-550 ◽  
Author(s):  
Prabuddha Ganguli ◽  
Vishnu R. Marathe
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Anisotropy ◽  
Spin Crossover

Interplay between spin crossover and exchange interaction in iron(III) complexes

2009 ◽  
Vol 81 (8) ◽  
pp. 1357-1383 ◽  
Author(s):  
Roman Boča ◽  
Ivan Nemec ◽  
Ivan Šalitroš ◽  
Ján Pavlik ◽  
Radovan Herchel ◽  
...  
Keyword(s):  
Experimental Data ◽  
Magnetic Susceptibility ◽  
Exchange Interaction ◽  
Spin Crossover ◽  
Magnetic Measurements ◽  
Spin States ◽  
Magnetic Exchange Interaction ◽  
Magnetic Exchange ◽  
Simultaneous Fitting ◽  
Polynuclear Metal Complexes

In the dinuclear and polynuclear metal complexes exhibiting the low-spin (LS) to high-spin (HS) transition, the spin-crossover phenomenon interferes with the magnetic exchange interaction. The latter manifests itself in forming spin-multiplets, which causes a possible overlap of the band originating in different reference spin states (LL, LH, HL, and HH). A series of dinuclear Fe(III) complexes has been prepared; the iron centers are linked by a bidentate bridge (CN-, and diamagnetic metallacyanates {Fe(CN)5(NO)}, {Ni(CN)4}, {Pt(CN)4}, and {Ag(CN)2}). Magnetic measurements confirm that the spin crossover proceeds on the thermal propagation. This information has been completed also by the Mössbauer spectral (MS) data. A theoretical model has been developed that allows a simultaneous fitting of all available experimental data (magnetic susceptibility, magnetization, HS mole fraction) on a common set of parameters.

scholarly journals Slow Magnetic Relaxation in a One-Dimensional Coordination Polymer Constructed from Hepta-Coordinate Cobalt(II) Nodes

2020 ◽  
Vol 6 (4) ◽  
pp. 45
Author(s):  
Amit Kumar Mondal ◽  
Arpan Mondal ◽  
Sanjit Konar
Keyword(s):  
Magnetic Susceptibility ◽  
Coordination Polymer ◽  
Magnetic Anisotropy ◽  
Ab Initio Calculations ◽  
Direct Current ◽  
Magnetic Relaxation ◽  
Relaxation Processes ◽  
Ac Magnetic Susceptibility ◽  
One Dimensional ◽  
Slow Magnetic Relaxation

A one-dimensional coordination polymer was synthesized employing hepta-coordinate CoII as nodes and dicyanamide as linkers. Detailed direct current (DC) and alternating current (AC) magnetic susceptibility measurements reveal the presence of field-induced slow magnetic relaxation behavior of the magnetically isolated seven-coordinate CoII center with an easy-plane magnetic anisotropy. Detailed ab initio calculations were performed to understand the magnetic relaxation processes. To our knowledge, the reported complex represents the first example of slow magnetic relaxation in a one-dimensional coordination polymer constructed from hepta-coordinate CoII nodes and dicyanamide linkers.

scholarly journals Interplay of Jahn-Teller Ordering and Spin Crossover in Co(II) Compounds

2020 ◽  
Vol 6 (4) ◽  
pp. 62
Author(s):  
Sophia Klokishner ◽  
Serghei M. Ostrovsky
Keyword(s):  
Experimental Data ◽  
Magnetic Susceptibility ◽  
Temperature Dependence ◽  
Theoretical Approach ◽  
Spin Crossover ◽  
Qualitative And Quantitative ◽  
Jahn Teller ◽  
Quantitative Explanation ◽  
Interionic Interactions

The spin crossover phenomena in Co(II) compounds are in the focus of the present paper. A microscopic theoretical approach for the description of spin transitions in mononuclear Co(II) compounds is suggested. Within the framework of this approach there are taken into account two types of interionic interactions that may be operative in the problem such as the electron-deformational interaction and the cooperative Jahn-Teller interaction arising from the coupling of the low-spin state of the Co(II) ion with the tetragonal vibrations of the nearest surrounding. The different role of these interactions in the spin transformation is demonstrated and discussed. On the basis of developed approach a qualitative and quantitative explanation of the experimental data on the temperature dependence of the magnetic susceptibility for the [Co(pyterpy)2](PF6)2, [Co(pyterpy)2](TCNQ)2⋅DMF⋅MeOH and [Co(pyterpy)2](TCNQ)2⋅MeCN⋅MeOH compounds is given.

Anisotropy of magnetic susceptibility in salt rocks from the German Zechstein Basin, Sondershausen mine

2019 ◽  
Vol 219 (1) ◽  
pp. 690-712
Author(s):  
Frances C Heinrich ◽  
Volkmar Schmidt ◽  
Michael Schramm ◽  
Michael Mertineit
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Anisotropy ◽  
Rock Salt ◽  
Impurity Content ◽  
Anisotropy Of Magnetic Susceptibility ◽  
Deformation History ◽  
Magnetic Minerals ◽  
Accessory Minerals ◽  
Salt Rocks ◽  
Rock Types

SUMMARY The anisotropy of magnetic susceptibility (AMS) of rocks reflects the alignment of certain minerals, and therefore it can be used to investigate the deformation history of rocks. However, for salt rocks, very few studies on the AMS of salt rocks and the influence of accessory minerals exist. In this study, we analysed the potential to use the AMS of salt rocks with low impurity content for fabric characterization. Samples of rock salt, sylvinite and carnallitite from a salt mine in Sondershausen (Germany) from the Late Permian (Zechstein 2, Stassfurt series) are investigated. The results of low-field AMS (LF-AMS) measurements show a very weak but significant magnetic anisotropy for sylvinite, carnallitite, and rock salt with an elevated content of accessory minerals. The AMS results are consistent in individual layers of the same rock type. In order to identify the magnetic minerals, which cause the magnetic anisotropy, the high-field AMS (HF-AMS) was measured using a torque magnetometer in order to separate ferrimagnetic and paramagnetic contributions to the AMS. A significant paramagnetic subfabrics exists, which reflects the alignment of phyllosilicates. The magnitude of the LF-AMS is considerably greater than that of the paramagnetic subfabric. This indicates the existence of a ferrimagnetic subfabric due to magnetite, which can have a different orientation than the paramagnetic subfabric. Differences in the orientation of the AMS in samples from two sites suggest a relationship of deformation history and AMS. At a site with dipping layers, the AMS orientation is independent of the bedding and shows large differences between individual lithological layers. In a tight fold, the AMS of all rock types has similar shape and orientation. We conclude that AMS in salt rocks can give meaningful information on the mineral fabric, which could be used in the analysis of the deformation history.

New Iron(II) Complexes [Fe(HC(Pz)3)2]A2 with Spin-Crossover

2015 ◽  
Vol 233-234 ◽  
pp. 534-537 ◽  
Author(s):  
Оlga G. Shakirova ◽  
Natalia V. Kuratieva ◽  
Evgeny V. Korotaev ◽  
Ludmila G. Lavrenova
Keyword(s):  
Magnetic Susceptibility ◽  
High Temperature ◽  
Ir Spectroscopy ◽  
Structure Analysis ◽  
Coordination Compounds ◽  
Spin Crossover ◽  
Color Change ◽  
Static Magnetic Susceptibility ◽  
X Ray ◽  
Magnetochemical Study

Three new coordination compounds of iron (II), [Fe (HC(Pz)3)2](C8H5O4)2.C8H6O4(I), [Fe (HC(Pz)3)2](C10H7SO3)2.2H2O (II) and Fe (HC(Pz)3)2](C12H25SO4)2(III), where HC(Pz)3is the tridentate chelatortris(pyrazol-1-yl) methane, have been synthesized and investigated by X-ray structure analysis, electronic and IR spectroscopy, static magnetic susceptibility method. The magnetochemical study of complexes I–III in the interval from 300 to 500 K showed that they possessed the high-temperature spin crossover1A1↔5T2accompanied by thermochromism (the pink ↔ white color change).

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