An Si photoelectrode with a nanoporous Au thin film for highly selective and efficient photoelectrochemical (PEC) CO 2 reduction reaction (CO 2 RR) is presented. The nanoporous Au thin film is formed by electrochemical reduction of an anodized Au thin film. The electrochemical treatments of the Au thin film critically improve CO 2 reduction catalytic activity of Au catalysts and exhibit CO Faradaic efficiency of 96% at 480 mV of overpotential. To apply the electrochemical pretreatment of Au films for PEC CO 2 RR, a new Si photoelectrode design with mesh-type co-catalysts independently wired at the front and the back of the photoelectrode is demonstrated. Due to the superior CO 2 RR activity of the nanoporous Au mesh and high photovoltage from Si, the Si photoelectrode with the nanoporous Au thin film mesh shows conversion of CO 2 to CO with 91% Faradaic efficiency at positive potential than the CO 2 / CO equilibrium potential.

We visualize the antisite exchange defects in LiFePO4 crystals with an ordered olivine structure by using annular dark-field scanning transmission electron microscopy (STEM). A recognizable bright contrast is observed in some of the Li columns of STEM images in a sample annealed at a lower temperature, which directly demonstrates the disordered occupations by Fe atoms. Furthermore, such exchange defects appear to be locally aggregated rather than homogeneously dispersed in the lattice, although their overall concentration is fairly low. The present study emphasizes the significance of atomic-level observations for the defect distribution that cannot be predicted by macroscopic analytical methods.

A record-high, near-theoretical intrinsic magnetoelectric (ME) coupling of 7 V cm Oe is achieved in a heterostructure of piezoelectric Pb(Zr,Ti)O (PZT) film deposited on magnetostrictive Metglas (FeBSi). The anchor-like, nanostructured interface between PZT and Metglas, improved crystallinity of PZT by laser annealing, and optimum volume of crystalline PZT are found to be the key factors in realizing such a giant strain-mediated ME coupling.

The distribution and local concentration of point defects in crystal lattices such as dopants and atomic vacancies have been recognized as significant factors that govern the overall electrical and optical properties of inorganic crystals. [1][2][3] The intentional use of impurities in semiconductors [1] and the formation of ionic vacancies in ion-conducting metal oxides [2] are well-known examples of displaying the correlation between atomic-scale chemical variations and resulting physical properties. Furthermore, as the chemically different environment induced by point defects leads to breaking of the ordered arrangement of atoms in crystals, mass and charge transport behaviors are also considerably affected by the presence of the defects. [4] In many lithium intercalation compounds, an ordered array of lithium is usually maintained. Therefore, the control of point defects, including cation disorder, is of major significance for application to electrodes in rechargeable batteries. A variety of investigations on lithium vacancies and cation intermixing have been reported for layered oxides.[5] In contrast, few experimental details showing the atomic-scale point defects in olivine-type lithium metal phosphates LiMPO 4 (where M = Fe, Mn, Ni, Co), are yet available, although these phosphates have attracted a great deal of attention as alternative cathode materials in lithium-ion batteries over the past decade.[6] As illustrated in Figure 1a, the lithium and the metal (M) ion in LiMPO 4 having an ordered olivine structure occupy different octahedral inter-

Morphology-controlled Au nanostructures are fabricatedviaelectroreduction of anodized Au thin films, exhibiting efficient catalytic activity for electrochemical CO2reduction.