[en] The ability to alter magnetic anisotropy values is of technological importance in the application of magnetic ultrahigh-density recording. By capping some other atoms onto the surface of a magnetic thin film or inserting a thin layer between the magnetic film and the substrate, we can change the surface or interface perpendicular magnetic anisotropy and then alter the magnetic properties of the film, such as the spin reorientation transition (SRT), in ultrathin ferromagnetic films. The SRT of face-centered-tetragonal (fct) Fe films grown on Cu(001) substrate is determined by the magneto-optical Kerr effect. We find that the out-of-plane magnetization changes to in-plane induced by a Ni-capping or a Co-inserting layer at 110 K. From the linear relation of the critical thickness of a fct-Fe film with Ni or Co covering when SRT occurs, the 'true' critical thickness of the pure fct-Fe film without coverage or buffer in the absence of structural transformation is obtained by setting the coverage to zero value. The estimated true critical thickness is approximately 4.3 ML for the Ni-capping method and 4.6 ML for the Co-inserting experiment, which are very close to the reported result for the Co-capping experiment.

[en] The nonlinear magneto-optical properties of polycrystalline Co films and single crystalline Fe films epitaxially grown on Co(001) substrate are studied ex situ and in situ, respectively, by the magnetization-induced second harmonic generation (MSHG) technique. The magnetic contrast in MSHG intensity can be clearly distinguished for the cobalt films, and dependence of the magnetic second harmonic intensity on the thickness of the magnetic film and a nonmagnetic covering is found, which is the result of the combined contributions of the magnetic surface and interfaces. A giant nonlinear Kerr rotation of more than 2 degrees, being at least an order of magnitude larger than its linear one, is achieved for the polycrystalline Co films. By using the MSHG method, the magnetic phase transitions of the ultrathin epitaxial Fe films at a thickness of about 4 ML and 11 ML can be successfully observed, showing sensitivity to the film structure and magnetic orders. If combined with the magneto-optical Kerr effect (MOKE), more information could be obtained.

[en] Here we develop a simple electrochemical method to fabricate novel multibranched root-tailed nanorod arrays by a novel electrochemical technique. A formation mechanism of the thick barrier layer and the root-tailed nanorod is proposed. Using this template-assisted method, three-dimensional nanorod arrays were prepared in a controlled manner, which helped to clarify the growth processes close to the bottom of the nanopores. The nanobranched wire, distinct from previous one-dimensional nanowires, should have potential applications in three-dimensional nanoelectronics and nanophotonics

[en] Highlights: • Ba₂SbO₂SX (X = Br, I), which contain stable complex ternary-anionic fragments are reported. • The optical properties are investigated, which are mainly attributed to the S-3p →Sb-5p​transitions. • Ba₂SbO₂SI exhibits an emission peak at 579 nm under 375 nm radiation. -- Abstract: Two isostructural compounds, Ba₂SbO₂SX (X = Br, I), have been successfully synthesized via solid state reaction. Their structures belong to the space group $C_{2h}^2-P21/m$ (No. 11) of the monoclinic system. They feature a quasi-two-dimensional (2D) network of distorted capped trigonal prisms [XBa₇]¹³⁺ along the a-b plane intercalated by [SbSO₂]^3- triangular pyramid. The optical band gaps of Ba₂SbO₂SBr and Ba₂SbO₂SI are 1.93 eV ad 2.03 eV, respectively. Ba₂SbO₂SI also exhibits an emission peak at 579 nm under 375 nm radiation. First-principles calculation reveals that the optical absorptions of Ba₂SbO₂SX are mainly attributed to the S-3p→Sb-5p transitions. The photoluminescence emission of Ba₂SbO₂SI is mainly contributed by the excitation of the states of the Sb−S bonds.