Magnetic flux rotation and associated magnetization peak inLa1.85Sr0.15CuO4crystals under tilted fields

Abstract

The magnetization vector in La 1.85 Sr 0.15 CuO 4 was measured as a function of magnetic field, temperature and time for fields tilted from the ab plane. For small tilting angles, the magnetization amplitude curves exhibit an additional peak in between the well-known first and second magnetization peaks. Assessment of the induction vector as a function of field reveals flux rotation from the ab plane towards the direction of the external field, beginning at the onset of the additional magnetization peak. This flux rotation causes a tilt of the current flow plane towards an "easy" direction, namely, the ab plane. The additional peak results from a competition between the current increase associated with this tilt and the intrinsic current decrease associated with the field increase.

Magnetization vector in the reversible region of the highly anisotropic cuprate superconductorTl2Ba2Ca2Cu3Mosqueira1, Rey2, Vidal3 2010Phys. Rev. B5050View full textAdd to dashboardCite

“…Let us note already here that until now only very few works include simultaneous measurements of M L and M T in the reversible mixed state, and they correspond to samples with a relatively moderate anisotropy. [25][26][27] The analyses of our present data shows that the angular dependence of M ⊥ follows the one predicted by a London approach for layered superconductors which includes the contribution of the pancakes fluctuations. The breakdown of this approach observed when θ is only 0.3 • away from π/2 is attributed to the mosaic spread present in the sample, and allowed to estimate a lower bound for the anisotropy factor of Tl-2223 as high as ∼190.…”

“…[25][26][27] In Fig. 2(a) we present the θ dependence of M T /M L , as results from the data in • | > ∼ 5…”

“…This fact has been used in previous works to determine the anisotropy factor from simultaneous measurements of M L (θ) and M T (θ). [25][26][27] In Fig. 2(a) we present the θ dependence of M T /M L , as results from the data in • , independently of the γ value used above ∼ 30.…”

Angular slippage from the crystallographic c-axis of the reversible magnetization vector in a tilted crystal of a highly anisotropic cuprate superconductor

“…The magnetization in the reversible region of high-T c cuprate superconductors (HTSC) is a very useful tool to probe the nature of the superconductivity in these materials. 1 Its phenomenology in the presence of magnetic fields applied perpendicular to the CuO 2 layers has been extensively studied, [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] including the behavior in the presence of tilted magnetic fields. In this case, due to the strong anisotropy of these materials, the reversible magnetization vector M lies almost perpendicular to the CuO 2 layers in a wide angular region, and a component transverse to the applied magnetic field (M T ) appears in addition to the longitudinal component (M L ).…”

“…[3][4][5] Such a transverse component has been studied through measurements of the magnetic torque, 6 but there are very few works where the two components of the magnetization vector are simultaneously studied. Some of them focus on irreversible properties of the tilted vortex lattice, as its dynamics upon rotation, 7-10 its relaxation, 7,11,12 , or the pinning forces acting on it. [13][14][15][16] Other works address effects associated with the layered superconducting structure appearing when the applied magnetic field is slightly tilted from the CuO 2 layers, as the vortex lockin to these layers.…”