Enhanced spin accumulation in nano-pillar-based lateral spin valve using spin reservoir effect

Lateral spin valves are ideal nanostructures for investigating spin-transport physics phenomena and promoting the development of future spintronic devices owing to dissipation-less pure spin current. The magnitude of the spin accumulation signal is well understood as a barometer for characterizing spin current devices. Here, we develop a novel fabrication method for lateral spin valves based on ferromagnetic nanopillar structures using a multi-angle deposition technique. We demonstrate that the spin-accumulation signal is effectively enhanced by reducing the lateral dimension of the nonmagnetic spin channel. The obtained results can be quantitatively explained by the confinement of the spin reservoir by considering spin diffusion into the leads. The temperature dependence of the spin accumulation signal and the influence of the thermal spin injection under a high bias current are also discussed.

Spin current and spin magnetoresistance of the heterostructure iridate/manganite interface

Kotelnikov Institute of Radioengineering and Electronics of Russian Academy of Sciences The paper presents the results of fabrication and structural study of SrIrO3/La0.7Sr0.3MnO3 heterostructures. The results of experimental studies of the spin current arising in the regime of ferromagnetic resonance are presented. The spin-orbit interaction present in 5d-oxides of transition metals, which is SrIrO3, provides an effective conversion of spin current to charge current due to the inverse spin Hall effect. The angular dependence of spin magnetoresistance makes it possible to determine the angle of the spin Hall effect.

Process gas dependence of the spin Peltier effect in Pt/Fe3O4 hybrid structures

The spin Peltier effect (SPE) in Pt/Fe3O4 hybrid structures with epitaxial Fe3O4 layers synthesized by reactive sputtering using two different process gases, Ar/O2 and Kr/O2, was investigated. The magnitude of the SPE-induced temperature modulation for the Fe3O4 film grown using Kr/O2 was approximately 40% larger than that grown using Ar/O2 despite almost the same crystalline structures and magnetic and electric properties of the films. The enhancement of the SPE signal for the film grown with Kr/O2 can be attributed to an increase in the spin current injected into the Fe3O4 film owing to its large roughness.

Development of a spin-injection device utilising Gadolinium Nitride

<p>In this thesis, the first steps in creating a realisable spin-injection transistor using ferromagnetic semiconductor electrodes are detailed. A spin-injection device utilising the ferromagnetic semiconductor gadolinium nitride has been designed, fabricated and electrically tested. In addition, an experimental setup for future measurements of a spin current in spin-injection devices was adapted to our laboratory-based off one developed by the Shiraishi group at Kyoto University. Issues encountered during fabrication were identified, and an optimal method for fabricating these devices was determined. Gadolinium nitride and copper were used to make the devices on Si/SiO2 substrates. The electrical integrity and applicability of the devices for future measurements of injected spin-current was determined through electrical device testing. Resistance measurements of electrical pathways within the device were undertaken to determine the successful deposition of the gadolinium nitride and copper. IV measurements to determine if the devices could withstand the current required for spin current measurements were done. The durability of the devices through multiple measurement types was observed. It was determined that although spin-injection devices utilising gadolinium nitride can be successfully fabricated, more work needs to be done to ensure that the electrical pathways through the copper and gadolinium nitride can be consistently reproducible to allow spin-injection measurements to be done.</p>

Development of a spin-injection device utilising Gadolinium Nitride

<p>In this thesis, the first steps in creating a realisable spin-injection transistor using ferromagnetic semiconductor electrodes are detailed. A spin-injection device utilising the ferromagnetic semiconductor gadolinium nitride has been designed, fabricated and electrically tested. In addition, an experimental setup for future measurements of a spin current in spin-injection devices was adapted to our laboratory-based off one developed by the Shiraishi group at Kyoto University. Issues encountered during fabrication were identified, and an optimal method for fabricating these devices was determined. Gadolinium nitride and copper were used to make the devices on Si/SiO2 substrates. The electrical integrity and applicability of the devices for future measurements of injected spin-current was determined through electrical device testing. Resistance measurements of electrical pathways within the device were undertaken to determine the successful deposition of the gadolinium nitride and copper. IV measurements to determine if the devices could withstand the current required for spin current measurements were done. The durability of the devices through multiple measurement types was observed. It was determined that although spin-injection devices utilising gadolinium nitride can be successfully fabricated, more work needs to be done to ensure that the electrical pathways through the copper and gadolinium nitride can be consistently reproducible to allow spin-injection measurements to be done.</p>