We have proposed spin quantum cross (SQC) devices, in which organic materials are sandwiched between two edges of magnetic thin films whose edges are crossed, towards the realization of novel beyond-CMOS switching devices. In SQC devices, nanometer-size junctions can be produced since the junction area is determined by the film thickness. In this study, we have fabricated Ni SQC devices with poly-3-hexylthiophene (P3HT): 6, 6-phenyl C61-butyric acid methyl ester (PCBM) organic materials and investigated the current-voltage (I-V) characteristics experimentally and theoretically. As a result of I-V measurements, ohmic I-V characteristics have been obtained at room temperature for Ni SQC devices with P3HT:PCBM organic materials, where the junction area is as small as 16 nm × 16 nm. This experimental result shows quantitative agreement with the theoretical calculation results performed within the framework of the Anderson model under the strong coupling limit. Our calculation also shows that a high on/off ratio beyond 10000:1 can be obtained in Ni SQC devices with P3HT:PCBM organic materials under the weak coupling condition.

Electron-beam-induced effects in preamorphized Sr2Nd8(SiO4)6O2 were investigated in situ using transmission electron microscopy with 200-keV electrons at temperatures ranging from 380 to 780 K. Within the electron-irradiated area, epitaxial recrystallization was observed from the amorphous/crystalline interface toward the surface, with the rate of recrystallization increasing as temperature increased from 380 to 580 K. Structural contrast features (i.e., O deficient amorphous material), as well as recrystallization, were observed outside of the irradiation area at temperatures from 680 to 780 K. Ionization-induced processes and local nonstoichiometry induced by oxygen migration and desorption are possible mechanisms for the electron-beam- induced recrystallization and for the formation of the structural contrast features, respectively.

Amorphous silicon carbides (a-SiC) fabricated by Xe+ ion implantation into 6H-SiC (0001) to fluences of 1015 and 1016/cm2 have been annealed at 850 °C for 1 hour. Transmission electron microscopy (TEM) observations revealed that the 1015 Xe+/cm2 implanted sample was completely recrystallized, while most of the a-SiC remains in the 1016 Xe+/cm2 implanted sample. Pair-distribution function analyses of both of the as-implanted samples show that the peak intensity of Si-C heteronuclear bonds is higher and the peak intensities of Si-Si and C-C homonuclear bonds are lower in the 1015 Xe+/cm2 implanted sample, indicating that the atomistic structure of the 1015 Xe+/cm2 implanted sample is more chemically ordered than that of the 1016 Xe+/cm2 implanted sample. This result suggests that more chemically ordered atomistic structure of 1015 Xe+/cm2 implanted a-SiC leads to complete recrystallization during thermal annealing.

Atomistic structures of amorphous silicon carbide generated by energetic particles were examined by electron diffraction techniques in combination with imaging plates. Atomic pair distribution functions revealed that not only heteronuclear (silicon-carbon) bonds but also homonuclear (silicon-silicon and carbon-carbon) bonds exist in the first coordination shell of amorphous silicon carbide induced by ion- or electron-beam-irradiation. Structural changes from amorphous silicon carbide to amorphous silicon were observed under the electron irradiation.

An in-situ electron diffraction structure analysis of La55Al25Ni20in the supercooled liquid temperature range (ΔTx) revealed a gradual structural change with a local phase separation due to strong atomic correlations especially of La-La and Al-Ni. On the basis of the structural data, structure models corresponding to the structures at temperatures between Tg and Tx were constructed using molecular dynamics (MD) simulation technique. These constructed structure models were then utilized for MD simulations to understand plastic deformation in the supercooled liquid state under a constant strain-rate. A larger elongation was obtained for the structure in the middle of the ΔTx range, but for the structure near Tx the elongation was relatively smaller which was supposed to be due to the local phase separation. These simulation results correspond well to the experimental elongation behaviors in the superplastic deformation that the elongation is enhanced in the middle of ΔTx but suppressed as the temperature is increased towards Tx.