2 15 / 10 cm W they can not be neglected in a full description of the laser-atom interaction. We explore the region that with increasing intensity switches from multiphoton to over the barrrier ionization and we find unlike in tunneling-type theories, that the ratio of ionization rates for electrons initially counter-rotating and co-rotating (with respect to the laser field) may be higher or lower than one._____________ *bauer@uni.lodz.pl

The ground-state properties of small silver clusters Agn (2⩽n⩽24) have been studied using a linear combination of atomic Gaussian-type orbitals within the density functional theory. The results show that the Ag13 clusters, due to their noticeable magnetic moment and their considerable highest occupied-lowest unoccupied molecular orbital gap, are promising candidates for the magnetic applications of nanoparticles. In particular, our study suggests that the silver nanoclusters made out of Ag13 clusters, as building blocks, are suitable for possible future applications in biomedicine, since they could improve some present-day difficulties of magnetic nanoparticles such as toxicity and opsonization.

We consider the transport properties in magnetic ultra-thin multilayers for electronic current in the plane of the surfaces. In the case of ultra-thin films, the conduction electron transport behavior is influenced by the shape and the thickness of a sample. The boundary conditions at the surface and interfaces lead to the electric charge density distribution across a film. We discuss the influence of sample thickness on some electronic properties like the Fermi energy, distribution of electrons and their spin polarisation. We justify some parameters introduced to the model potential whose values for spacer and ferromagnetic metals depend on the layer thickness. In this aspect the present approach constitutes improvement of Hood-Falicov model for the case of very thin layers.The discovery of giant magnetoresistance effects in Fe/Cr multilayers [1, 2] has triggered a large number of studies on the transport properties of magnetic multilayers. In spite of many experimental and theoretical investigations the description of the phenomenon is not completed and makes a challenge for many researchers [e.g. 3, 4]. In our paper [5] we have considered the transport properties in magnetic multilayers for electronic current in the layers parallel to the surfaces. This model is based on the effective s-band construction for the multilayer consisted of the spacer metallic and ferromagnetic, including s-d coupling, layers. In that model we have taken into account the spectrum energy of electrons in a trilayer and we have made the calculations of the Fermi level which is common for the effective s band electrons in tim whole sample [5]. The standard approach is determined by treating all of the valence electrons as being in a single free-electron like band with an isotropic effective mass, in each layer, i.e. spacer and ferromagnetic layer separately. In this paper we assume that a considered sample has a structure of three thin films which are characterised by means of the effective potentials reflecting the multilayered structure. Each of layers has got a crystal structure and the electronic density distribution is connected with the electric potential in a crystal assumed as a superposition of one-electronic potentials produced at the lattice sites. These sites are labeled by the two-dimensional vector j determined in the v-th layer parallel to the crystallographic plane and to the fihn surfaces. Each of n planes (v E (1, n)) *) Presented at ll

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We consider the transport properties in magnetic multilayers for electronic current in the plane of the surfaces. The model is based on the effective s-band construction for the multilayer consisting of the metallic spacer and two ferromagnetic layers characterized by s–d coupling. We discuss the quasielectron spectrum in its effective mass approximation, with the perturbation taken into account by the effective potential, which also includes the interface contributions. We find the energy dispersion and the Fermi level for the effective s-band common for electrons in the whole sample. The results are equivalent in fact to those obtained within the Hoon–Falicov model, but they seem to us much simpler and more transparent for their extensions and applications.