Theoretical and experimental results of electronic transport of spin quantum cross structure devices

Abstract

Recently, we have proposed quantum cross structure (QCS) devices that consist of two metalthin films deposited on organic films with edge-to-edge configuration like crossed fins for switching devices. In this paper, we propose a spin quantum cross structure (SQCS) device, which is a QCS device consisting of two magnetic thin films. We show theoretical and experimental results of electronic transport characteristics regarding SQCS devices. The calculation of the I-Vcharacteristics has been performed for the SQCS devices with the Nimagnetic thin films for both the electrodes within the framework of the Anderson model. Then, we fabricated a SQCS device with the Nimagnetic thin films and measured the I-Vcharacteristics by a four-terminal method. Also, the calculation of the magnetoresistance ratio has been done as a function of renormalized transfer matrices including magnetostriction effects and the other effects phenomenologically

Co thickness dependence of structural and magnetic properties in spin quantum cross devices utilizing stray magnetic fields

“…Typical results included the observation of ohmic characteristics in Ni/Ni devices, nanoscale tunneling phenomena in Ni/NiO/Ni devices, and the ballistic regime of nanoscale molecules in Ni/P3HT:PCBM/ Ni devices. [11][12][13] Although such nanoscale phenomena have been observed in SQC devices, these devices cannot function as spin-filter devices, because the squareness of the hysteresis loop of magnetic thin films on polyethylene naphthalate (PEN) substrates, used in the magnetic electrodes of SQC devices, is not sufficiently large. 14 In contrast, our ongoing research results suggest that Co thin films on borate glasses are good candidates for magnetic electrodes in SQC devices.…”

Large Thermoelectric Voltage in Point Contacts of Ni Ferromagnetic Metals

“…The junction area made of two edges can be scaled down to nanometer size due to the good resolution in making films by the metal-deposition rate, ranging from 0.01 nm/s to 1 nm/s. We have already realized the SQCS device with Ni ferromagnetic electrodes [6].…”

“…In this paper, we have theoretically investigated thermoelectric effects in PCs of Ni ferromagnetic metals using spin quantum cross structure (SQCS) devices, and we have verified the thermoelectric effects in PCs of Ni ferromagnetic metals experimentally. The SQCS device consists of two ferromagnetic metal thin films with their edges crossing, and sandwiches a few molecules and atoms [3][4][5][6]. The junction area made of two edges can be scaled down to nanometer size due to the good resolution in making films by the metal-deposition rate, ranging from 0.01 nm/s to 1 nm/s.…”

Surface morphologies and magnetic properties of Fe and Co magnetic thin films on polyethylene naphthalate organic substrates

“…According to our recent calculation within the framework of the Anderson model, SQC devices exhibit a giant MR effect at room temperature. 9 In this paper, toward the fabrication of SQC devices, we have investigated the surface morphologies and magnetic properties of Fe and Co thin films evaporated on polyethylene naphtalate (PEN) organic substrates and discussed their feasibility of use in SQC devices.…”