Electron-Donating Radialenes. Potential Donors for Molecular Organic (Super) Conductors and Ferromagnets

1989 ◽  
Vol 173 ◽  
Author(s):  
Z. Yoshida ◽  
T. Sugimoto ◽  
Y. Misaki
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Charge Transfer ◽  
Single Crystals ◽  
Temperature Change ◽  
Radical Cation ◽  
Electrical Conductivities ◽  
New Type ◽  
Ct Complexes

ABSTRACTThe electron-donating [n]radialenes (n=3,4,5) were prepared with the aim of developing both new type of organic (super)conductors and unprecedented organic/molecular ferromagnets. The charge-transfer (CT) complexes of 1,3-dithiole[4]radialene with TCNQ and of 1,3-benzodithiole-[4]radialene with TCNQF4 and DDQ showed comparatively high electrical conductivities in compressed pellets. The single crystals of PF6 and CIO4 salts of 1,3-benzodithiole[4]radialene radical cation revealed temperature change of electrical conductivity characteristic of a semiconductor. The magnetic properties of the bis(trifluoroacetate)salt of thioxanthene[3]-radialene dication and of the CT complexes of 1,3-benzodithiole[5]-radialene with DDQ, TCNQF4, and hexacyanohexamethylenecyclopropane, were also investigated from the ESR and/or magnetic susceptibility measurements.

CT Complexes Derived from Verdazyl Radicals

1998 ◽  
Vol 53 (4) ◽  
pp. 495-502 ◽  
Author(s):  
Shin’ichi Nakatsuji ◽  
Akari Kitamura ◽  
Atsushi Takai ◽  
Kazuyoshi Nishikawab ◽  
Yukio Morimoto ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Charge Transfer ◽  
Large Decrease ◽  
X Ray ◽  
Verdazyl Radicals ◽  
Crystal Structural ◽  
Ct Complexes

Several charge-transfer (CT) complexes derived from 1,5-diphenyl-3-(p-substituted-phenyl)- verdazyl radicals and TCNQF4 (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) or DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) were prepared and their magnetic properties were investigated. The X-ray crystal structural analyses on the CT complexes consisted of 3-(4-methoxyphenyl)-, 3-(4-tolyl)- as well as 3-(4-chlorophenyl)-verdazyl radicals and TCNQF4 were carried out and correlated with their magnetic properties in which large decrease of magnetic susceptibility was observed in each complex.

scholarly journals Single Crystal Growth and Physical Properties of Pyroxene CoGeO3

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 378
Author(s):  
Li Zhao ◽  
Zhiwei Hu ◽  
Hanjie Guo ◽  
Christoph Geibel ◽  
Hong-Ji Lin ◽  
...  
Keyword(s):  
High Pressure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Crystal Growth ◽  
Physical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Magnetic Moments ◽  
Single Crystal Growth ◽  
The Impact

We report on the synthesis and physical properties of cm-sized CoGeO3 single crystals grown in a high pressure mirror furnace at pressures of 80 bar. Direction dependent magnetic susceptibility measurements on our single crystals reveal highly anisotropic magnetic properties that we attribute to the impact of strong single ion anisotropy appearing in this system with TN∼33.5 K. Furthermore, we observe effective magnetic moments that are exceeding the spin only values of the Co ions, which reveals the presence of sizable orbital moments in CoGeO3.

Suppression of Ferromagnetism in EuxCa1-xB6

2012 ◽  
Vol 190 ◽  
pp. 97-100 ◽  
Author(s):  
V.V. Glushkov ◽  
A.V. Kuznetsov ◽  
I. Sannikov ◽  
A.V. Bogach ◽  
S.V. Demishev ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Curie Temperature ◽  
Single Crystals ◽  
Effective Magnetic Moment ◽  
Paramagnetic State ◽  
Low Field ◽  
Wide Range ◽  
Free Ion ◽  
The Eu

We report the magnetic properties of EuxCa1-xB6 single crystals (0.756x1) studied in the wide range of temperatures (1.8-300 K) and magnetic fields (up to 50 kOe). It was found that low field magnetic susceptibility χ (T) follows the Curie-Weiss law χ~(T-Θp)-1 at high temperatures for all the concentrations studied. The effective magnetic moment of the Eu2+ ion estimated from the data diminishes from the free ion value μeff7.93μB (μB - Bohr magneton) for x=1 to μeff7.3μB for x=0.756. A universal behavior of magnetic susceptibility χ~(T-Θ)-α (α=1.5) is detected close to the Curie temperature TC in the paramagnetic state at both metallic (x>xC~0.8) and dielectric (xC.

Magnetic properties of undoped and Co-doped n-type β–FeSi2.5 single crystals

2002 ◽  
Vol 17 (11) ◽  
pp. 2960-2965 ◽  
Author(s):  
E. Arushanov ◽  
L. Ivanenko ◽  
D. Eckert ◽  
G. Behr ◽  
U. K. Rößler ◽  
...  
Keyword(s):  
Activation Energy ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
External Field ◽  
Single Crystals ◽  
Spin Glasses ◽  
Paramagnetic Centers ◽  
Temperature Dependent ◽  
Paramagnetic Curie Temperature ◽  
Co Doped

Results of magnetization and magnetic susceptibility measurements on undoped and Co-doped FeSi2.5 single crystals are presented. The temperature dependence of the magnetic susceptibility of the Co-doped sample in the range of 5–300 K can be explained by temperature-dependent contributions due to paramagnetic centers and the carriers excited thermally in the extrinsic conductivity region. The values of the paramagnetic Curie temperature and activation energy of the donor levels were estimated. It is also shown that the magnetic susceptibility of Co-doped samples cooled in zero external field and in a field are different. This resembles the properties of spin-glasses and indicates the presence of coupling between magnetic centers.

Crystal Structure and Magnetic Properties of the Novel Hollandite Ba1.3Co1.3Ti6.7O16

2011 ◽  
Vol 66 (11) ◽  
pp. 1097-1100 ◽  
Author(s):  
Larysa Shlyk ◽  
Rainer Niewa
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Single Crystals ◽  
Magnetic Moment ◽  
High Spin State ◽  
The Novel ◽  
Charge Balance ◽  
Vertex Sharing ◽  
State Spin

Single crystals of the new barium hollandite Ba1.3Co1.3Ti6.7O16 were obtained from a BaCl2 flux (I2/m, Z = 1, a = 9.9470(4), b = 2.9714(2), c = 10.2260(5) Å , β = 90.906(2)◦). In the crystal structure piles of Ba atoms are situated within a framework of edge- and vertex-sharing octahedra (Co,Ti)O6. The composition was deduced from microprobe analyses, structure refinements and charge balance arguments in agreement with the observed magnetic properties. The temperature dependence of the magnetic susceptibility χ(T) of Ba1.3Co1.3Ti6.7O16 single crystals reveals paramagnetism down to 2 K. The value of the Co magnetic moment deduced from the Curie-Weiss law agrees well with the theoretical value of the high-spin state spin-only moment of μeff = 3.87 μB for Co2+ (S = 3/2)

Preparation and Spectroscopic Properties of the [Re2(C3S4Se)5]2- Anion Complex and Electrical Conductivities of the Oxidized Species [C3S4Se2- = 1,3-Dithiole-2-selone-4,5-dithiolate(2-)]

1995 ◽  
Vol 50 (11) ◽  
pp. 1748-1752 ◽  
Author(s):  
Takashi Maikawa ◽  
Motohiro Nakano ◽  
Ryuichi Arakawa ◽  
Gen-etsu Matsubayashi ◽  
Wasuke Mori
Keyword(s):  
Cyclic Voltammetry ◽  
Magnetic Susceptibility ◽  
Ir Spectra ◽  
Radical Cation ◽  
Room Temperature ◽  
Spectroscopic Properties ◽  
Anion Complex ◽  
Electrical Conductivities ◽  
Prepared Complex

The dinuclear rhenium(IV) complexes with the C3S4Se-ligand [1,3-dithiole-2-selone-4,5- dithiolate(2-)], [PPh4]2- (1) and [NEt4]2[Re2(C3S4Se)5] (2), were prepared. Complex 2 was oxidized by a reaction with [Fe(C5H5)2][PF6] or [TTF]3[BF4]2 (TTF·+ = the tetrathiafulvalenium radical cation) and by the current-controlled electrolysis to yield [NEt4]x[Re2(C3S4Se)5] (x = 0.15 and 0.5) and [TTF][Re2(C3S4Se)5]. The compounds exhibit electrical conductivities of 3.3 x 10-3 - 9.3 x 10-4 S cm-1 for compact pellets at room temperature. Electrochemical and spectroscopic properties of the complexes are discussed on the basis of cyclic voltammetry and ESR, XPS and IR spectra as well as the magnetic susceptibility of the TTF salt.

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