Magnetic anisotropy of paramagnetic and ferromagnetically ordered state of single crystal BaVSe3

Anisotropic magnetism of single crystal BaVSe3 was Studied for the first time by the combination of the susceptibility and torque methods. As reported previously for polycrystalline sample, BaVSe3 undergoes ferromagnetic ordering below 43 K. Well above ferromagnetic ordering temperature, the torque measurements reveal a continuous symmetry change that influences the ordered state accordingly. We found ferromagnetic easy axis in the vanadium chain direction, i.e., along the crystallographic c-axis. The presence of two ferromagnetic domains of opposite magnetization direction signifies uniaxial symmetry of the ordered ferromagnetic State

The magnetic state of the low dimensional CuTe2O5 compound below 20 K

We report low field studies of the static magnetic susceptibility and torque measurements in the temperature range 2-330 K for the powder and crystalline CuTe2O5 compound. We show that the observed extraordinarily large magnetic axis rotation below 20 K and small (nearly negligible), but highly anisotropic, low temperature susceptibility upturn (which is thus of intrinsic nature) is a consequence of the changes within the ground state d(9) orbital doublet which take place below 20 K, smoothly

Some electronic properties of the organic superconductor β-(BEDT-TTF )2I3

We report some results of magnetoresistance, magnetic susceptibility and magnetic anisotropy measurements on single crystals of the two dimensional organic superconductor βL-(BEDT-TTF)2I3 from 4.2 to 300 K. From the c* magnetoresistivity we deduce a value of 0.5 meV for the tight binding transfer integral tc, and show that there is significant conductivity anisotropy (a factor 5) in the a-b plane at low temperatures. A short value of the relaxation time, 0.5 ps at 9 K, indicates that electron transport between planes is becoming incoherent, which may affect the superconducting transition temperature. The static spin susceptibility shows little enhancement relative to the specific heat. The magnetic anisotropy data give evidence for a temperature dependent conduction electron diamagnetism when the magnetic field is perpendicular to the conducting planes.Nous avons mesuré de 300 K à 4,2 K la magnétorésistance, la susceptibilité et l'anisotropie magnétique de monocristaux du supraconducteur organique bi-dimensionnel βL-(BEDT-TTF)2I3. A partir de la magnétorésistance suivant c*, nous avons calculé une valeur de 0,5 meV pour l'intégrale de transfert tc dans un modèle de liaisons fortes. De plus, ces mesures indiquent que l'anisotropie de conductivité dans le plan a-b à basse température est d'un facteur cinq. La faible valeur du temps de relaxation (0,5 ps à 9 K) indique que le transport électronique entre plans devient incohérent, ce qui peut affecter la température de transition supraconductrice. La densité d'états dérivée de la susceptibilité de spin est en bon accord avec celle obtenue par chaleur spécifique. Lorsque le champ magnétique est dirigé perpendiculairement aux plans conducteurs, l'anisotropie magnétique provient en partie d'un diamagnétisme des électrons de conduction qui varie avec la température

Transport and magnetic properties of BaVSe3

We report a comprehensive study of transport, magnetotransport, and magnetic properties of single crystals of BaVSe3. The paramagnetic metal-ferromagnetic metal transition at 43 K was followed as a function of pressure by measuring the electrical resistivity and the thermoelectric power. The exponent of the low-temperature power-law dependence of the resistivity increases with pressure. The effective magnetic moment obtained from magnetic susceptibility in the paramagnetic regime is mu(eff)=1.40 mu(B). The study was completed by band-structure calculations based on density-functional theory both at ambient and high pressures. Transport coefficients of BaVSe3 resemble the high-pressure phase of BaVS3, which suggest that the replacement of sulfur with selenium can be viewed as chemical pressure