相关论文: AC susceptibility in deoxygenated YBCO single crys…
We report measurements of the irreversible magnetization M_i of a large number of YBa_2Cu_3O_7 single crystals with columnar defects (CD). Some of them exhibit a maximum in M_i when the density of vortices equals the density of tracks, at…
The magnetic characteristics for superconducting samples of different geometries (plates and films of various widths) and orientation with respect to external field are compared. A similarity is established between the magnetization curves…
Angular dependent torque measurements were performed on single crystals of CeCoIn$_5$, a heavy fermion superconductor ($T_{c0}$ = 2.3 K), in the temperature, $T$, range 1.9 K $\leq T \leq $ 20 K and magnetic fields $H$ up to 14 T. A large…
The c-axis reflectivity spectrum of underdoped YBa2Cu3O6.6 (YBCO) is measured below Tc=59K in parallel magnetic fields H//CuO2 up to 7T. Upon application of a parallel field, a new peak appears at finite frequency in the optical…
Samples of superconducting composite (100-x)YBa2Cu3O7-{\delta} + xNi (x = 1, 2.5, 5, 7.5, 10 and 15 wt.%) were synthesized. Scanning electron microscope (SEM) images revealed that the grain size of YBCO reduces gradually as Ni content is…
The experimental technique of a.c. susceptibility can be used as a probe of magnetic dynamics in a wide variety of systems. Its use is restricted to the low-frequency regime and thus is sensitive to relatively slow processes. Rather than…
In this article we present some particularly important issues regarding the CeCo$_{1-x}$Fe$_{x}$Ge$_{3}$ alloys. Firstly, the electrical resistivity below 2 K, down to 500 mK is studied to confirm the non-Fermi-liquid behavior around the…
In this work, we present the results of precise measurements of the resistivity of YNi$_2$B$_2$C single crystals with $T_{\rm c}$ = 15.5 K as a function of the temperature, and analyze the experimental data in the framework of the…
By using post-annealing and quenching technique, we show that the critical current density Jc,ab of KxFe2-ySe2 single crystals can be enhanced more than one order of magnitude up to ~ 2.1 \times 10^4 A/cm^2 at 1.8 K. The scaling law between…
We present a new experiment on YBa_2Cu_3O_{7-x} (YBCO) thin films using spatially resolved heavy ion irradiation. Structures consisting of a periodic array of strong and weak pinning channels were created with the help of metal masks. The…
Isofield magnetization curves are obtained and analyzed for three single crystals of YBa2Cu3O{7-x}, ranging from optimally doped to very underdoped, as well as the BCS superconductor Nb, in the presence of magnetic fields applied both…
According to the classical laws of magnetism, the shape of magnetically soft objects limits the effective susceptibility. For example, spherical soft magnets cannot display an effective susceptibility larger than 3. Although this is true…
From magneto-optical imaging performed on heavy-ion irradiated YBaCuO single crystals, it is found that at fields and temperatures where strong single vortex pinning by individual irradiation-induced amorphous columnar defects is to be…
We extend the Weak Crystallization theory to the case of metallic alloys. The additional ingredient -- itinerant electrons -- generates nontrivial dependence of free energy on the angles between ordering wave vectors of ionic density. That…
Motivated by puzzling results of recent experiments, we re-examine the response of a weakly pinned two-dimensional Wigner crystal to a uniform AC electric field. We confirm that at some disorder and magnetic field dependent frequency…
Pressure-volume-temperature data, along with dielectric relaxation measurements, are reported for a series of polychlorinated biphenyls (PCB), differing in the number of chlorine atoms on their phenyl rings. Analysis of the results reveals…
Alloying metals with other elements is often done to improve the material strength or hardness. A key microscopic mechanism is precipitation hardening, where precipitates impede dislocation motion, but the role of such obstacles in…
A candidate for the insulating phase of the 2D electron gas, seen in high mobility 2D MOSFETS and heterojunctions, is a Wigner crystal pinned by the incipient disorder. With this in view, we study the effect of collective pinning on the…
We investigated temperature (T)- and magnetic field-dependent optical conductivity spectra (\s\w) of a La_5/8-yPr_yCa_3/8MnO_3 (y~0.35) single crystal, showing intriguing phase coexistence at low T. At T_C < T < T_CO, a dominant…
We use a physically-based crystal plasticity model to predict the yield strength of body-centered cubic (bcc) tungsten single crystals subjected to uniaxial loading. Our model captures the thermally-activated character of screw dislocation…