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| Specific heat, C(T ), per mole of Yb for the model parameters in Ref. [18], in units of the Boltzmann constant kB, calculated via NLC (up to 4th order NLC together with Euler extrapolations) are compared with experimental data for Yb2Ti2O7. The black circles are data from Ref. |
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| a, In particles larger than about 10 nanometres, plasmons emerge as collective oscillations of a gas of conduction electrons, and have a frequency that is uncertain (double-headed arrow) because of collisions among the electrons and between the electrons and the particles' atomic lattice. b, In particles smaller than 10 nm, plasmons are associated with quantum electron transitions between occupied and unoccupied energy levels. As a result, the plasmon frequency and its uncertainty, which Scholl et al. accurately measured, are larger than those for bigger particles. |
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| Comparison of experimental data with quantum theory. Experimental, EELS-determined localized surface plasmon resonance energies of various Ag particle diameters are overlaid on the absorption spectra generated from the analytic quantum permittivity model (a) and the DFTderived permittivity model (b). The experimental bulk resonance energies are also included (grey dots) along with the theory prediction (grey line). Classical Mie theory peak prediction is given by the dashed white line. The experimental data begin to deviate significantly from classical predictions for particle diameters smaller than 10nm. Horizontal error bars represent 95% confidence intervals, as calculated through curve fitting and bootstrapping techniques. |
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| Thermoelectrics with a spin. |
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| Concept of the spin-dependent Peltier effect. a) A pure spin current is sent through a non-magnetic metal (N)/ferromagnetic metal (F) interface. In N, the Peltier heat current for both spin species is equal. As the flow direction in the two spin channels is opposite, the total heat current is cancelled. In F, the heat currents are different for majority and minority carriers, leading to a net heat current from the interface into F or vice versa. b), Generated temperature profile in the system. Spin relaxation in F reduces the spin current, thereby decreasing the induced heat current. |
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| Obtainable magnetization orientations of a helix coil. Micromagnetic simulations carried out on planar and coiled-up magnetic strips: (a) Initial magnetization is inplane, perpendicular-to-strip (left); hollow-bar-magnetized helix coils can be created (right). (b) Initial magnetization is in-plane, parallel-to-strip (left), results in a corkscrew-magnetized coil (right). (c) An out-of-plane magnetized strip (left) assembles into a radial-magnetized coil (right). |
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| (a) FC ZFC DC magnetization data, with an applied magnetic field (H) of 20 Oe. (b) The imaginary parts of AC susceptibility, with H =4 Oe. (c) Same as in (b), but focusing on the low-temperature region. (d) ZFC data with and without an intermediate wait (TW) at 25 K for 6000 seconds, showing distinct memory effects at TW as illustrated in the inset with a difference plot. |
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| Illustration of multiple-shot switching with CP excitation pulses. In the center of the excited area, both magnetic states can switch because of the high fluence, while at the edges (i.e., between the dashed borders) helicity-dependent switching occurs and therefore a single domain state is formed. Hence, by sweeping multiple CP excitation pulses over thesurface, a large area can be switched. |
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| Magnetization measurements of NP5, NP9 and NP16 dispersed in a polymer matrix: (a) hysteresis loops at 5 K, (b) ZFC/FC curves measured under a permanent field of 75 Oe and (c) imaginary part of the AC susceptibility. Inset: inverse of the blocking temperature as a function of the measurement time (dots), and fits to the Néel–Brown law (lines). |
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| All possible vortex states of the spherical surface. The left column demonstrates the model out-of-surface magnetization distribution given by Eq. (4) for all possible combinations of polarities. The right graph shows the corresponding distributions of the phase. For the correspondence, we use the notation p1p2, e.g. "+1-1" means p1 = +1 and p2 = -1 |
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| (a) Schematic view of a compensated AF interface. The interfacial energy is zero for this configuration, therefore no EB is allowed to occur. (b–d) A schematic view of a compensated hard ferrimagnetic interface in contact to a ferromagnet an… |
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| Magnetoelectric multiferroics are attractive materials for the development of low-power electrically controlled spintronic devices. Here we report the optimization of the exchange bias as well as the GMR effect of spin valves deposited on top of BiFeO3-based heterostructures. We show that the exchange bias can be electrically controlled through a change in the relative proportion of 109° domain walls and propose solutions toward a reversible process. |
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| Binary and multilevel data storage. a, In a classical binary ferroelectric random access memory (FERAM), a bit of information, with a logic value of ‘1’ or ‘0’, is encoded in the up (red block) or down (blue block) polarization direction of the device’s constituent cells. In this 36-bit example, the bits are stored in 6 × 6 cells, each of which stores one bit. Electrical wires (grey) are used to apply voltages across the cells to write and read the cells’ polarization. b, Lee et al.3 describe a multilevel FERAM that can store three bits in a single cell. In this way, three-bit logic states (000, 001, 010, 011, 100, 101, 110 and 111) can be stored in each of 3 × 4 cells of a smaller 36-bit memory array. Each state corresponds to a specific configuration of domains of opposite polarization in the cells. |
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| Temperature dependence of the saturation magnetization (Ms, top) and the exchange bias loop shift, Hex, of the bare gamma-Fe2O3 and Cu(0.5 nm)/Fe2O3 nanoparticles. The inset shows typical M vs mu0 H behavior of the Cu(0.5 nm)/gamma-Fe2O3 nanoparticles |
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| Purely nuclear SANS of spherical and cubic nanoparticles (scaled by 0.5 for display). Lines indicate fits to the model depicted in the right inset. Left inset: 10 deg sectors used for integrating the two-dimensional (2D) scattering. |
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| Island size dependence of the energy barrier Delta E. (a) The blue curve is a linear fit Delta E_lin=K(N-N0)The red curve shows the calculated energy barrier for domain wall formation Delta E_dw= 4 sigma sqrt(AK). . |
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| A simple aqueous synthesis of a superparamagnetic and biofunctional nanocomposite system is described. Chitosan-stabilized Fe3O4 nanoparticles were synthesized at room temperature and the surface charge of these nanocomposites was exploited to prepare nanoparticles decorated with gold. |
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| A: SEM of a typical sample. The scale bar indicates 0.2μm. B: Sketch representing the sample fabrication process. C-E: Current versus voltage in samples 1-3 (top to bottom), at 60mK and 0T. |
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| The Fe and Mn domain images as functions of tMn, taken at 105 K, at the region where the Fe film reveals the flipping magnetization (indicated by white arrows). The Mn layer yields nonvanishing IA at integer layer thickness and approaches to zero value at half-integer layer thickness. A very small IA signal for the Mn layer could be attributed to a nearly orthogonal included angle between the photohelicity and in-plane magnetization. |
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| (a) The scannable laser beam generates a local temperature gradient rT normal to the ferromagnetic thin film plane. The dc voltage VANE which arises due to the anomalous Nernst effect depends on the local magnetization M at the position ðx; yÞ of the laser beam. All investigated samples are patterned into 80 microm wide and 900 microm long Hall bars with contacts abeled as sketched. (b) VANE determined between contacts 2 and 4 as a function of the laser-spot position (x; y)and the external magnetic field magnitude H in a 50 nm thickCo2FeAl (CFA) film. |
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| a) Sketch of the composition of the fabricated nanodisks. b) AFM image of a selected fabricated structure (15 nm Au/10 nm Co/20 nm SiO2/15 nm Au). |
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| (a) The magnetization evolution in Gd24Fe66.5Co9.5 after the excitation with σ+ and σ− circularly polarized pulses at room temperature. (b) The averaged magnetization in the switched areas (∼5 μm) after σ+ and σ− laser pulses. (c) and (d) are results of multimacrospin simulations. |
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| Examples of nanocarrier delivery vehicles |
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| Ferroelectric ‘‘closure stripes’’ predicted by atomistic simulations of ultrathin films. |
