Nickel-cadium batteries for Apollo telescope mount

The operational testing and evaluation program is presented which was conducted on 20-ampere-hour nickel-cadmium (Ni-Cd) batteries for use on the Apollo telescope mount (ATM). The test program was initiated in 1967 to determine if the batteries could meet ATM mission requirements and to determine operating characteristics and methods. The ATM system power and charging power for the Ni-Cd secondary batteries is provided by a solar array during the 58-minute daylight portion of the orbit; during the 36-minute night portion of the orbit, the Ni-Cd secondary batteries will supply ATM system power. The test results reflect battery operating characteristics and parameters relative to simulated ATM orbital test conditions. Maximum voltage, charge requirements, capacity, temperature, and cyclic characteristics are presented

Observation of weak temperature dependence of spin diffusion length in highly-doped Si by using a non-local 3-terminal method

We conduct an experimental investigation of temperature dependence of spin diffusion length in highly-doped n-type silicon by using a non-local 3-terminal method. Whereas an effect of spin drift is not ignorable to bias- and temperature-dependence of spin signals in non-metallic systems except for the case of a non-local 4-terminal method, it is not fully conclusive how the spin drift affects spin transport properties in highly-doped Si in a non-local 3-terminal method that is often used in Si spintronics. Here, we report on temperature dependence of spin diffusion length in the Si, and it is clarified that the spin transport is less affected by an external electric field.Comment: 13 pages, 3 figure

Bipolar-Driven Large Magnetoresistance in Silicon

Large linear magnetoresistance (MR) in electron-injected p-type silicon at very low magnetic field is observed experimentally at room temperature. The large linear MR is induced in electron-dominated space-charge transport regime, where the magnetic field modulation of electron-to-hole density ratio controls the MR, as indicated by the magnetic field dependence of Hall coefficient in the silicon device. Contrary to the space-charge-induced MR effect in unipolar silicon device, where the large linear MR is inhomogeneity-induced, our results provide a different insight into the mechanism of large linear MR in non-magnetic semiconductors that is not based on the inhomogeneity model. This approach enables homogeneous semiconductors to exhibit large linear MR at low magnetic fields that until now has only been appearing in semiconductors with strong inhomogeneities.Comment: 23 pages, 4 figures (main text), 6 figures (supplemental material

Heteroepitaxial growth of ferromagnetic MnSb(0001) films on Ge/Si(111) virtual substrates

Molecular beam epitaxial growth of ferromagnetic MnSb(0001) has been achieved on high quality, fully relaxed Ge(111)/Si(111) virtual substrates grown by reduced pressure chemical vapor deposition. The epilayers were characterized using reflection high energy electron diffraction, synchrotron hard X-ray diffraction, X-ray photoemission spectroscopy, and magnetometry. The surface reconstructions, magnetic properties, crystalline quality, and strain relaxation behavior of the MnSb films are similar to those of MnSb grown on GaAs(111). In contrast to GaAs substrates, segregation of substrate atoms through the MnSb film does not occur, and alternative polymorphs of MnSb are absent

Influence of diffusion of Fe atoms into the emissive layer of an organic light-emitting device on the luminescence properties

This study investigated magnetic properties of multifilms, Fe/Al-O (Al-oxide), Fe/Al_q3 (tris-(8-hydroxyquinolinato)-aluminum), and Fe/Al-O/Al_q3, using vibrating sample magnetometer and ferromagnetic resonance. In the case of Fe/Al_q3-films, the decrease of magnetization value of Fe was observed compared with the other two. It was explained with diffusion of Fe atoms from the underlayer into the Al_q3 layer, and those diffused Fe atoms worked as quenching centers in the luminescence process of Al_q3

Transport properties of C_<60> thin film FETs with a channel of several-hundred nanometers

We report the transport properties of C_ thin film field-effect transistors (FETs) with a channel of several-hundred nanometers. Asymmetrical drain current I_D versus source-drain voltage V_ characteristics were observed. This phenomenon could be explained in terms of the high contact-resistance between the C_ thin film and the source/drain electrodes. This device showed a current on/off ratio > 10^5

Two Phase Spin Reversal Process in Co/Si/Co Trilayer Grown on GaAs(001)

Three times larger coercivity of Co/GaAs(001) bilayer compared to that of Co/Si(001) led us to fabricate a multilayer of Co/Si/Co/GaAs(001). The magnetization process of the multilayer was studied as a function of the thickness of the Si spacer layer. The coercivity of top Co layer on Si was found to get decreased with the increase in the thickness of Si spacer layer. Perpendicular resistance of the multilayer was also increased with increasing Si spacer layer thickness. We suggest that localized electronics defect states in the gap of amorphous Si modulate the magnetic properties of the multilayer. Hysteresis loop was changed from two phase to single phase with decreasing temperature and Si spacer layer thickness. The nice correspondence between the magnetoresistance peak and the flat-field region found in the magnetization curves provided the direct evidence of the existence of antiparallel spin states in the two Co layers through the Si spacer in Co/Si/Co/GaAs(001) multilayer

Variation of output properties of perylene field-effect transistors by work function of source/drain electrodes

Field-effect transistor (FET) devices with thin films of perylene have been fabricated with various metal electrodes exhibiting work functionφfrom 2.5 to 5.1 eV. All perylene FET devices show p-channel FET properties. The p-channel field-effect mobilityμ_p and the on-off ratio in the perylene FET increase with an increase inφof the metal electrodes. The n-channel conduction is also observed for the FET devices with Eu and Sr electrodes exhibiting smallφ. These results can be reasonably explained on the basis of energy barrier for hole or electron