The magnetic properties of the Tris(2-methyl-1,10-phenanthroline)iron(II) ion

1968 ◽  
Vol 21 (1) ◽  
pp. 83 ◽  
Author(s):  
HA Goodwin ◽  
RN Sylva
Keyword(s):  
Magnetic Properties ◽  
Thermal Equilibrium ◽  
Magnetic Moments ◽  
Anomalous Behaviour ◽  
Ligand Field ◽  
Temperature Dependent ◽  
Methyl Group ◽  
Temperature Range ◽  
Effective Strength

The magnetism of the salts [Fe mephen3]X2 (X = I-, ClO4-, BF4-, PF6-; mephen = 2-methyl- 1,l0-phenanthroline) has been investigated over the temperature range c. 100-300�K. The compounds exhibit anomalous behaviour, and this has been qualitatively interpreted as being the result of the presence of nearly equi-energetic ground terms 1A1 and 5T2 of the complexed iron(11) ion, a thermal equilibrium between these terms causing the magnetic moments to be markedly temperature dependent. This behaviour is apparently the result of the sterie hindrance to the coordination of an iron(11) ion induced by the presence of the methyl group in the ligand and the consequent lowering of the effective strength of the ligand field. The colour of the salts varies with temperature, and this has been discussed in terms of π-bonding between the iron(11) ion and the ligand.

MAGNETIC PROPERTIES OF U1-xDyxAlyNi5-y (y=0,1) SYSTEMS

2003 ◽  
Vol 17 (27n28) ◽  
pp. 1453-1460
Author(s):  
ILEANA LUPSA
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Spin Fluctuation ◽  
Magnetic Moments ◽  
Transition Temperatures ◽  
Temperature Range ◽  
Fluctuation Model ◽  
Magnetically Ordered

The magnetic properties of U 1-x Dy x Al y Ni 5-y (y=0,1) systems were investigated in the 2(5)–600 K temperature range and for fields up to 80 kOe. The systems having x≥0.2 are magnetically ordered with low transition temperatures and magnetization mainly due to the Dy contribution. The nickel exhibits magnetic moments, very weak in the low temperature range and well-defined effective moments over transition temperatures. The nickel behavior is discussed in terms of the spin fluctuation model.

Sulphur-nitrogen chelating agents. VIII. Magnetic behaviour of some cobalt(II) complexes at the crossover region

1969 ◽  
Vol 22 (9) ◽  
pp. 1825 ◽  
Author(s):  
PSK Chia ◽  
SE Livingstone
Keyword(s):  
Field Strength ◽  
Thermal Equilibrium ◽  
Chelating Agents ◽  
Magnetic Behaviour ◽  
Ligand Field ◽  
Crossover Region ◽  
Methyl Group ◽  
Quantitative Treatment

The bis-ligand cobalt(II) complexes of 6-methylpyrid-2-yi-N-(2?- methylthio-phenyl)methyleneimine (SNNMe) are spin-free and the corresponding complexes of 2-pyridyl-N-(2?- methylthiophenyl)methyleneimine (SNN) are spin-paired. This difference in magnetic behaviour arises from a lower effective ligand field strength of SNNMe, presumably due to the steric inter-ligand interference introduced by the methyl group in the 6-position of SNNMe. The moments of the cobalt(II) complexes are dependent on temperature and the departures from the Curie-Weiss law are quite anomalous. No quantitative treatment is given for the anomalous magnetic behaviour; however, the results are best explained as a thermal equilibrium between the nearly equi-energetic spin-paired and spin-free states of the cobalt(II) atom.

Magnetic Properties of Compounds RE2Cu2Mg (RE = Y, La, Pr, Nd)

2003 ◽  
Vol 58 (6) ◽  
pp. 497-500 ◽  
Author(s):  
Gunter Kotzybaa ◽  
Ratikanta Mishrab ◽  
Rainer Pöttgena
Keyword(s):  
Magnetic Properties ◽  
High Frequency ◽  
Remanent Magnetization ◽  
Magnetic Transition ◽  
Magnetic Moments ◽  
Temperature Dependent ◽  
Furnace Temperature ◽  
Pauli Paramagnetism ◽  
Magnetization Behavior ◽  
Curie Temperatures

The Mo2FeB2 type magnesium intermetallics RE2Cu2Mg (RE = Y, La, Pr, Nd) were synthesized from the elements by reactions in sealed tantalum tubes in a high-frequency furnace. Temperature-dependent magnetic susceptibility measurements of Y2Cu2Mg and La2Cu2Mg indicate Pauli paramagnetism. Pr2Cu2Mg and Nd2Cu2Mg show Curie-Weiss behaviour with experimental magnetic moments of 3.67(2) μB/Pr and 3.47(2) μB/Nd, respectively. Both compounds are ordered ferromagnetically at Curie temperatures of 12.0(5) (Pr2Cu2Mg) and 43.0(5) K (Nd2Cu2Mg). Pr2Cu2Mg shows a very complex magnetization behavior with an additional magnetic transition around 2.5 T. The neodymium compound shows a pronounced square loop behavior in the magnetization at 4.5 K with a high remanent magnetization of 1.55(1) μB/Nd atom and a coercive field of 0.31(1) T.

Pentanuclear heterobimetallic 3d-4f complexes of Ln2M3-type — structure and magnetism

2008 ◽  
Vol 62 (5) ◽  
Author(s):  
Matthias Siebold ◽  
Maria Korabik ◽  
Uwe Schilde ◽  
Jerzy Mrozinski ◽  
Peter Strauch
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Magnetic Moments ◽  
Powdered Sample ◽  
Temperature Dependent ◽  
Epr Spectrum ◽  
Metal Interactions ◽  
Spin Interactions ◽  
Metal Metal ◽  
Complete Series

AbstractFrom a series of pentanuclear, heterobimetallic complexes of the general composition [{Ln(H2O)n}2{Ni(dto)2}3] · xH2O, four complexes (Ln = Gd(III) with n = 4; Ln = Dy(III), Ho(III), or Er(III), with n = 5; x = 9–12; dto = 1,2-dithiooxalate) were studied due to their large magnetic moments (up to 14.65 B.M.). The magnetic properties of these complete series were measured at room temperature and the temperature dependent magnetic properties of the complexes Gd2Ni3, Dy2Ni3, Ho2Ni3, and Er2Ni3 were studied at room temperature down to 1.8 K. Whereas the intramolecular metal-metal distances were rather long (Ni1-Ni2: 11.0–11.5 Å; Ln-Ni: 6.0–6.3 Å), relatively short intermolecular metal-metal distances (Ni1-Ni2′: 3.5 Å; Er-Er′: 6.0 Å) were found in the crystal lattice, giving rise to weak intermolecular metal-metal interactions. These weak spin interactions were also supported by the EPR spectrum of a powdered sample of the diamagnetically undiluted Gd2Ni3 complex.

Magnetic properties of some copper(II) complexes of benzimidazolylalkanols

1973 ◽  
Vol 26 (5) ◽  
pp. 997 ◽  
Author(s):  
GJ Hamilton ◽  
E Kokot
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
General Formula ◽  
Magnetic Behaviour ◽  
Methyl Group ◽  
Temperature Range

The magnetic susceptibility in the temperature range 80-400 K is reported for copper(II) complexes of the general formula CuLX, where L is benzimidazole substituted in the 2-position by α- or β-hydroxyalkyl groups and in some cases also in the N-position by a methyl group and X is Br-, Cl-, or acetate. The magnetic behaviour of 1-(benzimidazol-2- yl)alkanolato complexes is interpreted in terms of antiferro- magnetically exchange-coupled pairs of copper atoms. The 2- (benzimidazol-2-yl)-alkanolato complex is a linear antiferromagnet.

Magnetic properties of rare earth chromium borates at high temperatures

2021 ◽  
pp. 166-170
Author(s):  
O.K. Kuvandikov ◽  
◽  
N.I. Leonyuk ◽  
V.V. Malsev ◽  
M.M. Kuzmin ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Temperature Dependence ◽  
High Temperatures ◽  
Wide Temperature Range ◽  
Magnetic Moments ◽  
Chemical Formula ◽  
Temperature Range ◽  
Curie Temperatures

Temperature dependence of the magnetic susceptibility has been studied for rare-earth borates NdCr3(BO3)4, SmCr3(BO3)4 and LuCr3(BO3)4 by the Faradey method in the wide temperature range (300-1200 K). The dependence for each phase follows the Curi - Weis law. The Curie temperatures, Neel temperatures and magnetic moments corresponding to the chemical formula of the crystals, have been found.

MAGNETIC PROPERTIES OF (GdxZr1-x)2CoAl3 SYSTEM

2009 ◽  
Vol 23 (10) ◽  
pp. 1345-1350
Author(s):  
ILEANA LUPŞA ◽  
T. PETRIŞOR
Keyword(s):  
Magnetic Properties ◽  
Characteristic Temperature ◽  
Magnetic Moments ◽  
Spin Fluctuations ◽  
Temperature Range ◽  
Paramagnetic Behavior ◽  
Ordered State ◽  
Paramagnetic Properties

The magnetic properties of the ( Gd x Zr 1-x)2 CoAl 3 system were investigated in the 4–700 K temperature range and fields up to 70 kOe. The systems seem to be ferrimagnetically ordered. In the ordered state, the Co moments opposite to the gadolinium ones have very low values. The paramagnetic properties evidence over a characteristic temperature T*, a Curie–Weiss type behavior and the presence of the effective magnetic moments on Co atoms. The paramagnetic behavior of cobalt is analyzed in the spin fluctuations model.

Thio derivatives of β-diketones and their metal chelates. X. The anomalous paramagnetism of some iron(III) chelates of monothio-β-diketones

1968 ◽  
Vol 21 (8) ◽  
pp. 1987 ◽  
Author(s):  
RKY Ho ◽  
SE Livingstone
Keyword(s):  
Iron Atom ◽  
Thermal Equilibrium ◽  
Room Temperature ◽  
Magnetic Behaviour ◽  
The Other ◽  
Ligand Field ◽  
Pairing Energy ◽  
Temperature Dependent ◽  
Magnetic Susceptibilities ◽  
Derivatives Of

The magnetic susceptibilities of the iron(111) chelates Fe(R1CS=CHCOR2)3 (R1 = Ph, p-MeC6H4, p-MeOC6H4, p-BrC6H4, 2-thienyl, 2-furyl, R2 = CF3; R1 = Ph, R2 = Ph, OEt) have been investigated over a temperature range. The iron(111) complex of ethyl thiobenzoylacetate (R1 = Ph, R2 = OEt) is of the high-spin type and obeys the Curie-Weiss law with θ =-8�k. The moments of the other complexes vary between 2.31 and 6.61 B.M. at room temperature and are temperature-dependent, ranging from 1.86 to 4.07 B.M. at 80�k, depending on the nature of R1 and R2 This behaviour is postulated to be due to a thermal equilibrium between the nearly equi-energetic spin-paired (t5/2g) and spin-free (t3/2ge2/g) configurations of the iron atom, resulting from the approximately equal magnitudes of the ligand field (Δ) and the pairing energy (π) in these complexes. The ligand field and consequently the magnetic behaviour are sensitive to the nature of R1 and R2: electron-withdrawing groups appear to be the most effective in increasing the population of the spin-paired configuration.

Anomalous magnetic properties in the solid state of salts of the Bis[2-(2-pyridylamino)-4-(2-pyridyl)thiazole]iron(II) ion

1967 ◽  
Vol 20 (3) ◽  
pp. 479 ◽  
Author(s):  
RN Sylva ◽  
HA Goodwin
Keyword(s):  
Magnetic Properties ◽  
Solid State ◽  
Crystal Lattice ◽  
Temperature Dependence ◽  
Iron Atom ◽  
Thermal Equilibrium ◽  
Magnetic Moments ◽  
Chloride Salt ◽  
Marked Influence ◽  
Free Iron

The magnetism of nine salts containing the bis[2-(2-pyridylamino)-4-(2- pyridyl)thiazole]iron(II) ion has been investigated over the temperature range c. 100-350�K. All salts were obtained hydrated and in some instances the magnetism of the anhydrous salts was also investigated. The magnetism was found to be markedly dependent on the anion of the salt. Two distinct classes of compounds were recognized- those obeying a simple Curie-Weiss law and having magnetic moments corresponding to the expected value for spin-free iron(II); and those whose temperature dependence of magnetism was found to be anomalous. For these compounds the magnetic moments varied from almost spin-paired to almost spin-free values. The anomalous behaviour has been qualitatively interpreted in terms of a thermal equilibrium between the nearly equi-energetic spin-paired and spin-free states of the iron atom. The differences in the behaviour of different salts have been ascribed to differences in crystal lattice forces. The presence of hydrate water in the crystal lattice has been shown in some instances to have a marked influence on the magnetism. Two magnetically isomeric forms of the anhydrous chloride salt have been obtained. It has been shown that there is an association between the magnetism and colour of the compounds.

Magnetic properties of RE10TCd3 (RE = Ho, Er, Tm, Lu; T = Fe, Co, Ni, Ru) and 57Fe Mössbauer spectroscopic data of Y10FeCd3

2016 ◽  
Vol 71 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Oliver Niehaus ◽  
Michael Johnscher ◽  
Theresa Block ◽  
Birgit Gerke ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Properties ◽  
High Frequency ◽  
Spectroscopic Data ◽  
Magnetic Moments ◽  
Iron Site ◽  
Muffle Furnace ◽  
Temperature Dependent ◽  
X Ray ◽  
Free Ion ◽  
Pauli Paramagnetism

AbstractFourteen X-ray-pure intermetallic compounds RE10TCd3 (RE = Ho, Er, Tm, Lu; T = Fe, Co, Ni, Ru) and Y10FeCd3 were obtained through high-frequency melting of the elements in sealed niobium tubes and subsequent annealing in a muffle furnace. They adopt the Er10FeCd3 structure, a ternary ordered version of the Co2Al5 type. Temperature-dependent magnetic susceptibility measurements show Pauli paramagnetism for the lutetium compounds Lu10FeCd3, Lu10CoCd3, and Lu10RuCd3. The RE10TCd3 phases with holmium, erbium, and thulium show Curie–Weiss paramagnetism and the experimental magnetic moments match with the free ion values of RE3+. All these compounds order antiferromagnetically. The highest Néel temperature was observed for the holmium compounds, e.g. 46.5 K for Ho10RuCd3. Some of the RE10TCd3 phases show field-induced spin reorientations. A 57Fe Mössbauer spectrum of Y10FeCd3 confirms the single crystallographic iron site.

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