We have investigated the electron transport in endohedral metallofullerene Ce@C82 single-molecule transistors (SMTs) together with that in reference C84 SMTs. The vibrational modes (bending and stretching) of the encapsulated single Ce atom in the C82 cage appear in Coulomb stability diagrams for the single-electron tunneling through Ce@C82 molecules, demonstrating the single-atom sensitivity of the transport measurements. When a bias voltage larger than 100 mV is applied across the source/drain electrodes, large hysteretic behavior is observed in the current-voltage (I-V) characteristics. At the same time, the pattern in the Coulomb stability diagram is changed. No such hysteretic behavior is observed in the I-V curves of hollow-cage C84 SMTs, even when the bias voltage exceeds 500 mV. This hysteretic change in the I-V characteristics is induced by a nanomechanical change in the configuration of the Ce@C82 molecule in the nanogap electrode due to the electric dipole that exists in Ce@C82.

Rare-earth iron oxides (RFe2O4) have attracting attention as new electronic device materials because of their numerous functionalities, such as electronic ferroelectricity, ferrimagnetism, and high infrared absorption. In this paper, nearly monophasic Y bFe2O4 films were prepared on α-Al2O3(001) substrates by the spin coating method using an aqueous-based Y bFe2O4 solution. The solution was composed of a stoichiometric ratio of Y b(CH3COO)3 and Fe(NO3)3 with excess chelating agents. After heat treatment above 800 °C, well-crystallized and highly (001)-oriented Y bFe2O4 started to epitaxially form on the substrate under controlled oxygen partial pressure with H2/CO2 gas mixtures. X-ray pole figure analysis confirmed the following epitaxial relationship: Y bFe2O4[100](001)//α-Al2O3[100](001). Moreover formation of an Fe3O4 interracial layer between Y bFe2O4 and α-Al2O3 was detected by high-resolution transmission electron microscopy. Presence of the Fe3O4 interracial layer seemed to release the lattice misfit with the substrate. The Fe2+/Fe3+ ratio in the obtained Y bFe2O4 films was nearly stoichiometric and the indirect bandgap assigned to Fe2+ → Fe3+ charge transfer excitation was found to be ∼0.4 eV by optical spectroscopy. A clear magnetic transition from the paramagnetic state to the ferrimagnetic state occurred at ∼230 K.

Rare-earth iron oxides (RFe 2 O 4 ) have attracting attention as new electronic device materials because of their abundant functionalities such as ferroelectricity, ferrimagnetism, and high infrared absorption. These properties are strongly related to the mixed iron valance states between Fe 2+ and Fe 3+ . We tried to prepare RFe 2 O 4 films by using soft chemical method. The films were prepared by spin-coating of viscous aqueous solutions of Yb(CH 3 COO) 3 and Fe(NO 3 ) 3 with citric acid. The molar ratio between Yb:Fe was 1:2 and the citric acid: metal ratio was set to 3.75:1. After the coating, the films dried at 100°C for 10 min in air were, heat-treated at 900°C for 0.2 h in H 2 /CO 2 gases to control oxygen partial pressure, and quenched. The obtained films were characterized by using XRD, SEM, EDS, Mössbauer, and optical-absorption spectra. The XRD pattern clearly indicated the well-crystallized and nearly monophasic YbFe 2 O 4 formed on the substrates above 900°C to control the oxygen partial pressure. Equal amount of Fe 2+ and Fe 3+ ions was present in the films. The films showed small band-gap and large optical absorbance in infrared region.

Purpose In a previous study, a new method was described using the sperm immobilization test (SIT) with computer‐aided sperm analysis (CASA). However, obtaining high‐quality sperm as needed was a known issue. Here, we compared the results of using frozen‐thawed sperm and fresh sperm for the SIT using the CASA method. Methods For the frozen‐thawed preparation, 500 μL of condensed semen and 500 μL of Sperm Freeze were mixed in a cryovial and cryopreserved in liquid nitrogen. Density gradient centrifugation was used for the collection of motile sperm in both the fresh and frozen‐thawed sperm preparations. A total of 50 serum samples were prepared for both the fresh and frozen‐thawed sperm with each sample tested containing 10 μL of serum, 1 μL of either fresh or frozen motile sperm suspension, and 2 μL of complement. Sperm motilities were measured using CASA after a 1‐hour incubation period for both fresh and frozen‐thawed sperm. Results Both fresh and frozen‐thawed sperm reacted similarly when exposed to serum containing sperm‐immobilizing antibodies asserting the use of frozen‐thawed sperm for the diagnosis of immunological infertility. Conclusion These results suggest the possibility of using cryopreserved sperm for the SIT when fresh sperm is unavailable.

This paper − describes ． a ． novel local surface m6dification meth6d ． of an organic ph σtosensitive polymer using an atomic fbrce microscopy ． As organic photosensitive polymer ， urethane − urea copolymer was employed ， Topography of the copolymer containing an azo dye cIm be modu 玉 ated by the intensity distribution of the light ． The surface of th 臼 copolymer film waS locally fabricated by strong near field optical sourOe generated at the 、 edge of the metal ． coated tip due to a strong field en 紅 ancement ． effect し mder laser illumination ． ， The suCcessfUlly fabricated dot patterns have been investigated about the relationship bf the dot depth and light illumination time ． Those experimental systems and results presented here are conceivab 且 e fbr high density storage and nanometer − ' scale fabrication of polymer material ． Key Mo ！