Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions.

Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current voltage, and this rectification voltage strongly varies with the external magnetic field. We find that the rectification magnetoresistance in Al/Ge Schottky heterojunctions is as large as 250% at room temperature, which is greatly enhanced as compared with the conventional magnetoresistance of 70%.

Electrical control of memristance and magnetoresistance in oxide magnetic tunnel junctions.

Electric-field control of magnetic and transport properties of magnetic tunnel junctions has promising applications in spintronics. Here, we experimentally demonstrate a reversible electrical manipulation of memristance, magnetoresistance, and exchange bias in Co/CoO-ZnO/Co magnetic tunnel junctions, which enables the realization of four nonvolatile resistance states. Moreover, greatly enhanced tunneling magnetoresistance of 68% was observed due to the enhanced spin polarization of the bottom Co/CoO interface.

Spin memristive magnetic tunnel junctions with CoO-ZnO nano composite barrier.

The spin memristive devices combining memristance and tunneling magnetoresistance have promising applications in multibit nonvolatile data storage and artificial neuronal computing. However, it is a great challenge for simultaneous realization of large memristance and magnetoresistance in one nanoscale junction, because it is very hard to find a proper spacer layer which not only serves as good insulating layer for tunneling magnetoresistance but also easily switches between high and low resistance states under electrical field. Here we firstly propose to use nanon composite barrier layers of CoO-ZnO to fabricate the spin memristive Co/CoO-ZnO/Co magnetic tunnel junctions.

Effect of native defects and Co doping on ferromagnetism in HfO2: first-principles calculations.

First-principles calculations of undoped HfO(2) and cobalt-doped HfO(2) have been carried out to study the magnetic properties of the dielectric material. In contrast to previous reports, it was found that the native defects in HfO(2) could not induce strong ferromagnetism. However, the cobalt substituting hafnium is the most stable defect under oxidation condition, and the ferromagnetic (FM) coupling between the cobalt substitutions is favorable in various configurations.

N-(2-Formamido-eth-yl)formamide.

The complete molecule of the title compound, C(4)H(8)N(2)O(2), is generated by a crystallographic inversion center. The occurence of N-H⋯O hydrogen bonds results in the formation of a two-dimensional infinite network parallel to the (010) plane. In this plane, the hydrogen bonds define graph-set motif R(4) (4)(22) in a centrosymmetric array by the association of four mol-ecules.

Bis(4-pyridylmeth-yl) hexa-nedioate.

The asymmetric unit of the title compound, C(18)H(20)N(2)O(4), contains one half-mol-ecule. The mol-ecule lies on an inversion centre and is roughly planar, the chains between the two pyridine rings being only slightly twisted, with torsion angles ranging from 170.9 (1) to 177.

3,3'-(2-Oxocyclo-pentane-1,3-di-yl)dipropane-nitrile.

The complete mol-ecule of the title compound, C(11)H(14)N(2)O, is generated by crystallographic twofold symmetry, with the C=O group lying on the rotation axis. In the crystal structure, weak C-H⋯N inter-actions form zigzag chains of mol-ecules.

4-Hydroxy-2,2,6,6-tetra-methyl-piperidinium trifluoro-acetate.

The title compound, C(9)H(20)NO(+)·C(2)F(3)O(2) (-), is an important inter-mediate in the synthesis of hindered light stabilizers. The piperidinium ring adopts a chair conformation with the hydroxyl group in an equatorial position. The crystal packing is stabilized by O-H⋯O and N-H⋯O hydrogen bonds.