Related papers: Vortex Redistribution below the First-Order Transi…
We report on transport properties of millimetric super-lattices of CoFe nanoparticles surrounded by organic ligands. R(T)s follow R(T) = R_0.exp(T/T_0)^0.5 with T_0 ranging from 13 to 256 K. At low temperature I(V)s follow…
In classical XY kagome antiferromagnets, there can be a novel low temperature phase where $\psi^3=e^{i3\theta}$ has quasi-long-range order but $\psi$ is disordered, as well as more conventional antiferromagnetic phases where $\psi$ is…
In recent experiments with a superconducting nanosized Pb bridge formed between a scanning tunneling microscope tip and a substrate, superconductivity has been detected at magnetic fields, which are few times larger than the third (surface)…
We report vibrating coil magnetometry of the spin ice system Ho2Ti2O7 down to ~0.04 K for magnetic fields up to 5 T applied parallel to the [111] axis. History dependent behavior emerges below T*_0 ~ 0.6 K near zero magnetic field, in…
Co3V2O8 is an orthorhombic magnet in which S=3/2 magnetic moments reside on two crystallographically inequivalent Co2+ sites, which decorate a stacked, buckled version of the two dimensional kagome lattice, the stacked kagome staircase. The…
The magnetoresistance of thin superconducting strips subject to a perpendicular magnetic field B and low temperatures T manifests a sequence of alternating superconductor-insulator transitions (SIT). We study this phenomenon within a quasi…
We present magnetization and Hall effect measurements on the pyrochlore iridate Nd2Ir2O7. Previous muon spin rotation measurements have shown that the system undergoes an unusual transition at T$_M$ = 110 K into a magnetic phase lacking…
The nature of the magnetic transition of the Na-rich thermoelectric Na$_{0.75}$CoO$_2$ at 22K was studied by positive muon-spin-rotation and relaxation ($\mu^+$SR) spectroscopy, using a polycrystalline sample in the temperature range…
We have investigated low energy nuclear spin excitations in double perovskite compounds R$_2$CoMnO$_6$ (R = Y,Tb) by inelastic neutron scattering with a high-resolution back-scattering spectrometer. We observed inelastic signals at about…
We report the structure and magnetism of PrOFeAs, one of the parent phases of the newly discovered Fe-As superconductors, as measured by neutron powder diffraction. In common with other REOFeAs materials, a tetragonal-orthorhombic phase…
In an electrically conducting fluid, vortices stretch out a weak, large-scale magnetic field to form strong current sheets on their edges. Associated with these current sheets are magnetic stresses, which are subsequently released through…
We consider the vortex matter in a three-dimensional two-component superconductor with individually conserved condensates with different bare phase stiffnesses in a finite magnetic field, such as the projected superconducting state of…
Neutron scattering is used to characterise the magnetism of the vortices for the optimally doped high-temperature superconductor La(2-x)Sr(x)CuO(4) (x=0.163) in an applied magnetic field. As temperature is reduced, low frequency spin…
We report magnetization measurements under high hydrostatic pressure in the newly discovered pyrochlore superconductor RbOs_2O_6 (T_c\simeq6.3K at p=0). A pronounced and {\it positive} pressure effect (PE) on T_c with dT_c/dp…
We report the single-crystal X-ray analysis of the structure of the pyrochlore oxide superconductor KOs$_2$O$_6$. The structure was identified as the $\beta$-pyrochlore structure with space group $Fd\bar{3}m$ and lattice constant $a$ =…
Impurities, inevitably present in all samples, induce elastic transitions between quasiparticle states on the contours of constant energy. These transitions may be seen in Fourier transformed scanning tunneling spectroscopy experiments,…
We study the extent of the reversible region in the vortex phase diagram of recently available RbOs$_2$O$_6$ single crystals \cite{Rogacki08a} by means of bulk magnetization measurements. We found that the irreversible magnetic response…
We have investigated magnetization(M), magnetocaloric effect(MCE) and magnetothermopower(MTEP) in polycrystalline Pr0.6Sr0.4MnO3, which shows a second-order paramagnetic to ferromagnetic transition near room temperature (TC = 305 K).…
We calculate the transition line of the first-order melting of vortex lattice in a three-dimensional type-II superconductor in fields of several Tesla, using the results from the density-functional theory of vortex melting in two dimensions…
We report on simulations of layered superconductors using the Lawrence-Doniach model in the framework of the lowest Landau level approximation. We find a first order phase transition with a $B(T)$ dependence which agrees very well with the…