Position error-free control of magnetic domain-wall devices via spin-orbit torque modulation.

Magnetic domain-wall devices such as racetrack memory and domain-wall shift registers facilitate massive data storage as hard disk drives with low power portability as flash memory devices. The key issue to be addressed is how perfectly the domain-wall motion can be controlled without deformation, as it can replace the mechanical motion of hard disk drives. However, such domain-wall motion in real media is subject to the stochasticity of thermal agitation with quenched disorders, resulting in severe deformations with pinning and tilting. To sort out the problem, we propose and demonstrate a new concept of domain-wall control with a position error-free scheme. The primary idea involves spatial modulation of the spin-orbit torque along nanotrack devices, where the boundary of modulation possesses broken inversion symmetry. In this work, by showing the unidirectional motion of domain wall with position-error free manner, we provide an important missing piece in magnetic domain-wall device development.

Multiple Walker breakdowns in magnetic multilayers.

Herein, we report an exotic domain-wall dynamics showing double Walker breakdowns in magnetic multilayer films composed of two magnetic layers. Such multiple Walker breakdowns are attributed to the internal magnetic dipole field, which is antisymmetric on the domain walls of the lower and upper magnetic layers. A micromagnetic simulation shows four phases of the domain-wall dynamics, which result in a phase diagram with the phase boundaries of the double Walker breakdown fields. Such double Walker breakdowns lead to two minima in the variation of the domain-wall velocity, as often observed experimentally.

Effect of fermented earthworm cast on egg production and egg quality as well as removal of odor in feces from egg laying hens.

The objective of the present study was to determine the effect of feeding fermented earthworm casts (EEC) to layers on egg-laying performance, blood lipid profiles, cecal microflora, and fecal odor removing performance. A total of 200 Hyline Brown layer chicks at 33-week-old were used in this study. They were randomly assigned to two numerically equal groups with 100 replications per treatment for 10 weeks. All the birds were caged individually. The control group was not treated with EEC. The EEC group was treated with top dressing containing 3.5% EEC. The present study revealed that egg production and egg weight were increased after feeding diet containing EEC at the top dressing level. Haugh unit, eggshell thickness, and eggshell breaking strength of EEC group were higher than those of control group. Egg yolk was determined for fatty acid profiling. It was found that EEC group had higher ratio of unsaturated- to saturated fatty acid as compared to control group. Lower ratios of n-6 to n-3 fatty acids were found in the egg yolk of EEC group. Plasma triglyceride and total cholesterol contents were lower in the EEC group. However, high density lipoprotein-cholesterol content was higher in the EEC group as compared to that in control group. The number of cecal Lactobacillus was increased while the population of Escherichia coli and coliform bacteria decreased in the EEC group. Fecal ammonia and hydrogen sulfide contents were lower in the EEC group as compared to those in control group. Taken together, these results suggested that EEC could improve egg production and egg quality. In addition, it could remove odour from laying-hen manure.

Fabrication of Highly Ordered and Well-Aligned PbTiO3/TiN Core-Shell Nanotube Arrays.

Highly ordered and well-aligned PbTiO3/TiN core-shell nanotubes are fabricated via an anodic aluminum oxide templating route followed by TiN and TiO2 atomic layer deposition deposition and a subsequent PbO vapor reaction. PbTiO3/TiN nanotubes keep their original shape after the vapor phase reaction, and they display well-defined piezoresponse hysteresis curves with remnant piezoresponse of 38 pm V(-1) .

Ion distributions at the water/1,2-dichloroethane interface: potential of mean force approach to analyzing X-ray reflectivity and interfacial tension measurements.

We present X-ray reflectivity and interfacial tension measurements of the electrified liquid/liquid interface between two immiscible electrolyte solutions for the purpose of understanding the dependence of interfacial ion distributions on the applied electric potential difference across the interface. The aqueous phase contains alkali-metal chlorides, including LiCl, NaCl, RbCl, or CsCl, and the organic phase is a 1,2-dichloroethane solution of bis(triphenylphosphor anylidene) ammonium tetrakis(pentafluorophenyl)borate (BTPPATPFB). Selected data for a subset of electric potential differences are analyzed to determine the potentials of mean force for Li(+), Rb(+), Cs(+), BTPPA(+), and TPFB(-). These potentials of mean force are then used to analyze both X-ray reflectivity and interfacial tension data measured over a wide range of electric potential differences. Comparison of X-ray reflectivity data for strongly hydrated alkali-metal ions (Li(+) and Na(+)), for which ion pairing to TPFB(-) ions across the interface is not expected, to data for weakly hydrated alkali-metal ions (Rb(+) and Cs(+)) indicates that the Gibbs energy of adsorption due to ion pairing at the interface must be small (<1 k(B)T per ion pair) for both the CsCl and RbCl samples. This paper demonstrates the applicability of the Poisson-Boltzmann potential of mean force approach to the analysis of X-ray reflectivity measurements that probe the nanoscale ion distribution and the consequences of these underlying distributions for thermodynamic studies, such as interfacial tension measurements, that yield quantities related to the integrated ion distribution.

Communications: Monovalent ion condensation at the electrified liquid/liquid interface.

X-ray reflectivity studies demonstrate the condensation of a monovalent ion at the electrified interface between electrolyte solutions of water and 1,2-dichloroethane. Predictions of the ion distributions by standard Poisson-Boltzmann (Gouy-Chapman) theory are inconsistent with these data at higher applied interfacial electric potentials. Calculations from a Poisson-Boltzmann equation that incorporates a nonmonotonic ion-specific potential of mean force are in good agreement with the data.

Structure and depletion at fluorocarbon and hydrocarbon/water liquid/liquid interfaces.

The results of x-ray reflectivity studies of two oil/water (liquid/liquid) interfaces are inconsistent with recent predictions of the presence of a vaporlike depletion region at hydrophobic/aqueous interfaces. One of the oils, perfluorohexane, is a fluorocarbon whose superhydrophobic interface with water provides a stringent test for the presence of a depletion layer. The other oil, heptane, is a hydrocarbon and, therefore, is more relevant to the study of biomolecular hydrophobicity. These results are consistent with the subangstrom proximity of water to soft hydrophobic materials.

Ion distributions near a liquid-liquid interface.

Mean field theories of ion distributions, such as the Gouy-Chapman theory that describes the distribution near a charged planar surface, ignore the molecular-scale structure in the liquid solution. The predictions of the Gouy-Chapman theory vary substantially from our x-ray reflectivity measurements of the interface between two electrolyte solutions. Molecular dynamics simulations, which include the liquid structure, were used to calculate the potential of mean force on a single ion. We used this potential of mean force in a generalized Poisson-Boltzmann equation to predict the full ion distributions. These distributions agree with our measurements without any adjustable parameters.