We show that in metamagnetic shape memory alloys exhibiting a magnetostructural first order phase transition the direct transition from ferromagnetic austenite to nonmagnetic martensite is isothermal. In contrast to the direct transformation, the reverse one nonmagnetic martensite–ferromagnetic austenite is athermal, just as are athermal both direct and reverse martensitic transformations in co...

Magnetic vortex that consists of an in-plane curling magnetization configuration and a needle-like core region with out-of-plane magnetization is known to be the ground state of geometrically confined submicron soft magnetic elements. Here magnetodynamics of relatively thick (50-100 nm) circular Ni80Fe20 dots were probed by broadband ferromagnetic resonance in the absence of external magnetic f...

In copper-oxides that show high-temperature superconductivity (HTS), the critical temperature (Tc) has a dome-shaped doping dependence. The cause of demise of both Tc and superfluid density ns on the overdoped side is a major puzzle. A recent study of transport and diamagnetism in a large number of overdoped La2-xSrxCuO4 (LSCO) films shows that this cannot be accounted for by disorder within th...

Present spintronic research [1,2,3] involves virtually all materials families but ferromagnetic semiconductors are particularly attractive as they combine resources of both semiconductors and ferromagnets. We describe here recent studies of ferromagnetic Crand Mn-based II-VI diluted magnetic semiconductors (DMS) excluding, however, oxides that are subject of another presentation [4]. Properties...

We have performed a two-color time-resolved magneto-optical Kerr effect (MOKE) study of a ferromagnetic InMnAs/GaSb heterostructure. We observed ultrafast photoinduced changes in the MOKE signal induced by a large density of spin-polarized transient carriers created only within the InMnAs layer using intense 140 fs mid-infrared pulses. Our data clearly demonstrates that magnetic properties, e.g...

Rights: © 2003 American Physical Society (APS). This is the accepted version of the following article: Enkovaara, J. & Heczko, O. & Ayuela, A. & Nieminen, Risto M. 2003. Coexistence of ferromagnetic and antiferromagnetic order in Mn-doped Ni2MnGa. Physical Review B. Volume 67, Issue 21. 212405/1-4. ISSN 1550-235X (electronic). DOI: 10.1103/physrevb.67.212405, which has been published in final f...

Neutron scattering was used to determine the spin structure and the magnon spectrum of the Mott-Hubbard insulator YTiO3. The magnetic structure is complex, comprising substantial G-type and A-type antiferromagnetic components in addition to the predominant ferromagnetic component. The magnon spectrum, on the other hand, is gapless and nearly isotropic. We show that these findings are inconsiste...

Despite their inherent non-equilibrium nature1, living systems can self-organize in highly ordered collective states2,3 that share striking similarities with the thermodynamic equilibrium phases4,5 of conventional condensed matter and fluid systems. Examples range from the liquid-crystal-like arrangements of bacterial colonies6,7, microbial suspensions8,9 and tissues10 to the coherent macro-sca...

2014A crystal field analysis of the 3d9 multiplet of Cu+ + in K2CuF4 is presented, taking into account optical absorption spectra, linear dichroism, and the anisotropy of the g tensor. The calculations are based on local D’4h symmetry arising from elongated ligand octahedra with their long axes in the c planes, as it has been proposed theoretically and confirmed by X-ray studies. An additional ...

Two and three dimensional random Ising models with a Gaussian distribution of couplings with variance J and non-vanishing mean value J0 are studied using the zero-temperature domain-wall renormalization group (DWRG). The DWRG trajectories in the (J0, J) plane after rescaling can be collapsed on two curves: one for J0/J > rc and other for J0/J < rc. In the first case the DWRG flows are toward th...