We determine the boundary of the fully polarized ferromagnetic ground state in the one dimensional Kondo lattice model at partial conduction electron band filling by using a newly developed infinite size DMRG method which conserves the total spin quantum number. The obtained paramagnetic to ferromagnetic phase boundary is below J ≈ 3.5 for the whole range of band filling. By this we solve the c...

The phase diagrams of the three-state Ghatak-Sherrington spin-glass (or random Blume-Capel) model are obtained in mean-field theory with replica symmetry in order to study the effects of a ferromagnetic bias and finite random connectivity in which each spin is connected to a finite number of other spins. It is shown that inverse melting from a ferromagnetic to a low-temperature paramagnetic pha...

The magnetic phase of thin Fe overlayers on top of a Rh~001! surface has been probed using the surface magneto-optical Kerr effect. Quite surprisingly, we have found a suppression of ferromagnetic order up to six atomic layers of Fe. Not until Fe coverage reaches above seven layers does a ferromagnetic order start to develop. The suppression of ferromagnetic order is attributed to the tetragona...

We demonstrate that the spin Hall effect in a thin film with strong spin-orbit scattering can excite magnetic precession in an adjacent ferromagnetic film. The flow of alternating current through a Pt/NiFe bilayer generates an oscillating transverse spin current in the Pt, and the resultant transfer of spin angular momentum to the NiFe induces ferromagnetic resonance dynamics. The Oersted field...

Magnetic properties (coercivity and magnetization) of ferromagnetic films are strongly affected by the proximity to materials that undergo a metal to insulator transition. Here, we show that stress associated with structural changes across the metal-insulator phase transition in VO2 and V2O3 produces a magnetoelastic anisotropy in ferromagnetic films (Co and Ni) deposited on top of the oxides. ...

There is considerable controversy surrounding the nature of the paramagnetic to ferromagnetic phase transition in La(0.7)Ca(0.3)MnO3. We have used transmission electron microscopy to determine whether the phase transition is first or second order. On warming through the transition point, the ferromagnetic phase retreats from the sample surface as it is replaced by the paramagnetic phase. This c...

A novel synthetic route to polymer-coated ferromagnetic colloids of metallic cobalt has been developed. Well-defined end-functional polystyrenes were synthesized using controlled radical polymerization and used as surfactants in the thermolysis of dicobaltoctacarbonyl to afford uniform ferromagnetic nanoparticles. The presence of the polymer shell enabled prolonged colloidal stability of disper...

Pairing of oxygen holes into heavy bipolarons in the paramagnetic phase and their magnetic pair breaking in the ferromagnetic phase (the so-called current-carrier density collapse) has accounted for the first-order ferromagnetic-phase transition, colossal magnetoresistance, isotope effect, and pseudogap in doped manganites. Here we propose an explanation of the phase coexistence and describe th...

Experimental evidence of left-handed transmission is demonstrated through an array of ferromagnetic microwires. We used amorphous magnetic microwires to take advantage of both electric and magnetic responses locally generating a double negative medium at microwave frequencies, where the ferromagnetic resonance effects take place. The dilution of the responses of the ferromagnetic material provi...