A combined study of magnetic susceptibility and AC resistance was performed on melt-spun Cu-Co granular magnetic ribbons. The AC resistance as a function of temperature has a sharp maximum. We associate it with a diverging correlation length at the temperature of collective freezing of magnetic moments via increasing magnetic losses in the induced non-uniform field. Application of this model to...

One type of order that has been observed to compete with superconductivity in cuprates involves alternating charge and antiferromagnetic stripes. Recent neutron scattering studies indicate that the magnetic excitation spectrum of a stripe-ordered sample is very similar to that observed in superconducting samples. In fact, it now appears that there may be a universal magnetic spectrum for the cu...

The susceptibility of ~Sm0.65Sr0.35!MnO3 shows an unusual temperature dependence above the Curie temperature which is attributed to the presence of small manganese-ion clusters with S'9. A field-induced transition is observed in the paramagnetic state, which corresponds to a doubling of the cluster size and an increase of the strength of the interaction between them. The continuous transition f...

We study the influence of magnetic scattering on the Josephson critical current, Ic, in a superconductor/ferromagnetic metal/superconductor (SFS) junction by a tunneling Hamiltonian approach. An analytical formula of Ic is given in the fourth order perturbation theory as regards the tunneling matrix element. The Ic exhibits the damped oscillatory dependence on the thickness of the ferromagnetic...

within the effective-field theory with correlations (eft), a transverse random field spin-1 ising model on the simple cubic (z=6) lattice is studied. the phase diagrams, the behavior of critical points, transverse magnetization,  internal energy, magnetic specific heat are obtained numerically and discussed for different values of p the concentration of the random transverse field.

Electrical control of magnetic properties is crucial for device applications in the field of spintronics. Although the magnetic coercivity or anisotropy has been successfully controlled electrically in metals as well as in semiconductors, the electrical control of Curie temperature has been realized only in semiconductors at low temperature. Here, we demonstrate the room-temperature electrical ...

Gd5(SixGe1-x)4 has a complex magnetic-structural phase diagram which can be divided into three distinct regions. I t exhibits an unusual first order coupled magnetic-structural phase transition in the region 0.41 ≤ x ≤ 0.51. A series of magnetostrictive strain measurements were carried out as a function of magnetic field strength at different temperatures and as a function of temperature at nea...

Bulk magnetization measurements (5-320 K; 0-8T) reveal that below room temperature Mn0.9Ti0.1CoGe exhibits two magnetic phase transitions at ~178 K and ~280 K. Neutron diffraction measurements (3-350K) confirm that the transition at ~178K is due to the structural change from the low-temperature orthorhombic TiNiSi-type structure to the higher temperature hexagonal Ni2In-type structure while the...

Electroweak phase transition in a magnetic field is investigated within the one-loop and ring diagram contributions to an effective potential. All fundamental fermions and bosons are included with their actual values of masses . The only free parameter remains the Higgs boson mass mH . It is shown that the ring diagrams affect the phase transition drastically . The effective potential is real a...