Metallomesogens and Amorphous Metallopolymers: Magnetic Properties

1992 ◽  
Vol 247 ◽  
Author(s):  
W. Haase ◽  
K. Griesar ◽  
C. Erasmus-Buhr

ABSTRACTThe magnetic susceptibility data in the temperature range of 4.2 K up to 300 K in the crystalline state of a metal lomesogen containing a Cu(II)-center are reported and discussed. Also magnetic properties of a Cu(II) containing chemically modified polymethylmethacrylate are presented. The interpretation of data, based on the Curie-Weiss-equation, shows a negative Weiss constant in the range up to θ = −27 K. An intermolecular long range antiferromagnetic exchange interaction at least in the solid or amorphous state has been discussed.

1989 ◽  
Vol 175 ◽  
Author(s):  
Wolfgang Haase ◽  
Stefan Gehring ◽  
Bettina Borchers

AbstractMagnetic susceptibility data (300–520 K) of monomeric and dimeric mesogenic copper(II) compounds are presented. Different magnetic effects arising from the paramagnetic Cu(II)-centres and the diamagnetic anisotropy of the mesogenic groups are observed and discussed with respect to possible inter molecular interactions.


2021 ◽  
Vol 1028 ◽  
pp. 15-20
Author(s):  
Muhammad Abdan Syakuur ◽  
Yati Maryati ◽  
Togar Saragi ◽  
Risdiana

Structure and magnetic properties of electron-doped superconducting cuprates have been investigated in order to study the effect of magnetic impurity to its physical properties. Here, we reported structure and magnetic properties of Eu1.88Ce0.12Cu1-yZnyO4+α-δ (ECCZO) with y = 0 and 0.03. The properties of ECCZO have been studied from X-ray diffraction data and temperature dependence of magnetic susceptibility data, to elucidate the effect of partial substitution of non-magnetic impurity Zn for Cu to its structure, Tc and the value of magnetic moments per unit volume extracted from susceptibility data in normal state. Magnetic-susceptibility measurements were carried out down to 2 K on-field cooling at 5 Oe for Eu1.88Ce0.12Cu1-yZnyO4+a-d with y = 0 and 0.03. For ECCZO sample with y = 0 and d = 0.0669 indicated the change of magnetic behavior from paramagnetic to diamagnetic below 12 K which is addressed to the Tc onset of this samples. Diamagnetic behavior is observed starting from about 12 K. Above 12 K, all samples show paramagnetic behavior with the values of the magnetic moment in every volume unit increased with increasing Zn.


2002 ◽  
Vol 57 (10) ◽  
pp. 1129-1132 ◽  
Author(s):  
A. Elmali ◽  
Y. Elerman ◽  
I. Svoboda

The mixed-ligand dinuclear complex (2,2'-dipyridyl)-(2-acetylphenolato)copper(II) perchlorate was synthesized and its crystal structures determined. The structure consists of a dimeric unit involving a planar Cu2O2 group. The coordination sphere of the Cu atom can be described as an alongated octahedron where the basal plane is formed by the two N atoms of the 2,2'-dipyridyl molecule and the two O atoms of the acetophenon anion. Two apical Cu - O contacts complete the 4+2 coordination of the Cu atoms. They correspond to one of the O atoms of the perchlorate anion and to the O atom of the second unit. Magnetic susceptibility data obey the Curie-Weiss law with θ = -8.1(2) K. The decreasing of the effective magnetic moment from 1.94(8) μB at 300 K to 1.86(8) μB at 70 K and the negative Weiss constant indicate weak antiferromagnetic interactions between the two copper atoms in the dimeric units.


1996 ◽  
Vol 453 ◽  
Author(s):  
H.-C. Zur Loye ◽  
P. Núñez ◽  
M. A. Rzeznik

AbstractThe one-dimensional compounds Sr3MgPtO6, Sr3MgIrO6, Sr3MgRhO6, Sr3GdRhO6, have been synthesized and structurally characterized by Rietveld refinement of powder X-ray diffraction data. All four compounds are isostructural with the rhombohedral K4CdCl6-type structure. The structure consists of infinite one-dimensional chains of alternating face-shared MO6 octahedra (M = Pt, Ir, Rh) and M′O6 (M′ = Gd, Mg) trigonal prisms. The strontium cations are located in a distorted square antiprismatic environment. Magnetic susceptibility data show that both Sr3MgIrO6 and Sr3MgRhO6 obey the Curie-Weiss law with θ = −6(1) K, and θ= −15(3)K, respectively. Sr3GdRhO6 obeys the Curie law with μeff = 7.80 B.M, consistent with an oxidation state of +3 for both rhodium and gadolinium.


1986 ◽  
Vol 89 ◽  
Author(s):  
M. Gorska ◽  
J. R. Anderson ◽  
Z. Golacki

AbstractThe magnetization and magnetic susceptibility of Bridgman-grown Pb1-xGdxTe have been measured over a temperature range from 2 to 300 K and in magnetic fields from 0.01 to 50 κOe. The x-values of the crystals ranged from 0.03 to 0.07. The magnetic susceptibility followed a Curie-Weiss behavior, χ = C/(T + θ), with positive θ implying an antiferromagnetic exchange interaction between Gd ions. The magnetic field dependence of the magnetization was fitted to a modified Brillouin function with parameter values that agreed fairly well with those from Curie-Weiss plots. The magnitude of θ was comparable to the value found for Pb1-xMnxTe for similar x values; but since the ion spin is bigger for Gd this suggests that the exchange interaction in Gd-doped PbTe is roughly half the value in Mn-doped PbTe.


RSC Advances ◽  
2017 ◽  
Vol 7 (53) ◽  
pp. 33305-33313 ◽  
Author(s):  
P. Fuentealba ◽  
V. Paredes-Garcia ◽  
D. Venegas-Yazigi ◽  
I. D. A. Silva ◽  
C. J. Magon ◽  
...  

EPR and magnetic susceptibility data of composites based on MnPS3 show the influence of the intercalated species on their magnetic properties.


1995 ◽  
Vol 50 (11) ◽  
pp. 1587-1590 ◽  
Author(s):  
Yalcin Elerman ◽  
Mehmet Kabak ◽  
Ingrid Svoboda ◽  
Hartmut Fuess ◽  
Klaus Griesar ◽  
...  

The tetracupferronato-bis(μ-methoxy)-diiron(III) complex has been synthesized in acetonitrile and its crystal structure determined. C26H26N8O10Fe2, monoclinic, space group C2/c, a =18.425(3), b = 12.999(2), c = 15.046(3) Å, β = 124.66(2)°,V = 2964(1) Å3, Z = 4, wR(2) = 0.097 from 1491 reflections (F2). Two iron(III) atoms are at special positions in six-fold coordination, bridged by O with a Fe-O-Fe angle of 102.4(1)° and a distance between two iron(III) centers of 3.075(1) Å. Temperature-dependent magnetic susceptibility measurements reveal a antiferromagnetic exchange interaction (J = -14 cm-1) between the iron(III) centers.


2007 ◽  
Vol 1032 ◽  
Author(s):  
Jing Ju ◽  
Juns Sasaki ◽  
Naoki Toyota ◽  
Katsumi Tanigaki

AbstractA new microporous polyborate, NaCuB7O12.nH2O, is synthesized using boric acid as a flux. It contains a 14-membered ring framework built up by CuO6 octahedra, BO4 tetrahedra and BO3 triangles. The spin-1/2 dimers of Cu2+ ions are connected by BO3 to form an infinite ladder along the b-axis. Magnetic susceptibility data between 2 and 330 K are presented, and the data are accurately fitted by theoretical predictions of Bleaney-Bowers for the spin-1/2 dimer, with J/kB = -153.8 K, and g = 1.98, where J is the intradimer exchange interaction constant and g is the Landé g factor.


1999 ◽  
Vol 52 (3) ◽  
pp. 205 ◽  
Author(s):  
Elsa E. Sileo ◽  
Daniel Vega ◽  
Mará T. Garland ◽  
Ricardo Baggio ◽  
Miguel A. Blesa

The crystal structures of Na2Cu(2,3-pydc)2.8H2O (1) and Cu(3,4-pydc).3·5H2O (2) (pydc = pyridinedi- carboxylato) are presented. Compound (1) is monoclinic, space group C 2/c, with a 21·274(1), b 6 ·114(1), c 17·136(1) Å, β 101·62(1)°, Z 4, Dc 1·776 g cm-3 ; compound (2) is also monoclinic, space group P 21/c, with a 7·272(2), b 11·319(3), c 25·453(9) Å, β 90·58(1)°, Z 4, Dc 1·850 g cm-3 . Their stereochemistries are analysed, and compared with other copper(II) pyridine-2,6-dicarboxylates. Ligand constraints are shown to determine the crystal structures and the magnetic properties. Thermal dependence of magnetic susceptibility data and t.g., d.t.g. and d.t.a. measurements are also presented.


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