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Magnetic quantum-well (QW) states are probed with angle- and spin-resolved photoemission to address critical issues pertaining to the origin of the giant magnetoresistance (GMR) optimization and oscillatory coupling of magnetic multilayers. Two epitaxial systems are highlighted: Cu/Co(wedge)/Cu(100) and Cr/Fe(100)-whisker. The confinement of Cu sp-QW states by a Co barrier requires a characteristic Co thickness of 2.2[+ or -]0.6 [Angstrom], which is consistent with the interfacial Co thickness reported to optimize the GMR of permalloy-Cu structures. The controversial k-space origin of the 18-[Angstrom] long period oscillation in Fe/Cr multilayers is identified by the vector that spans the d-derived 'lens' feature of the Cr Fermi surface, based on the emergence of QW states with 17[+ or -]2 [Angstrom] periodicity in this region.

Experimental studies using the surface magnetooptic Kerr effect help analyze the magnetic and related structures of ultrathin Fe films present as wedge structures onto Ag(100) and Cu(100). Thermal fluctuations in an isotropic two-dimensional Heisenberg system inhibit the long-range order and/or generate domain structures exhibiting unusual properties. Film thickness and temperature exert significant influence on spin-reorientation transition for Fe/Ag(100) and Fe/Cu(100).

To accurately simulate the steady-state responses of a functionally graded piezoelectric structure (FGPS) and cure the "overly-stiff" of finite element method (FEM), the coupled thermal-electrical-mechanical inhomogeneous cell-based smoothed finite element method (CICS-FEM) is proposed. The gradient smoothing technique is introduced into FEM and a "close-to-exact" stiffness is obtained. Based on the basic theory of FGPS, the thermal field is introduced into the electrical-mechanical coupling field and the multi-physics coupling equations are given in conjunction with the cell-based smoothed finite element method. CICS-FEM is verified with several examples, and there is a satisfactory agreement between the current solution and the reference solution. Therefore, the developed method to solve the steady-state response of FGPS can provide a reference for the design and manufacture of smart devices. [ABSTRACT FROM AUTHOR]

A study was conducted to analyze the magnetic characteristics of ultrathin iron films prepared on stepped W(001) and Pd(001) substrates. The substrates were mechanically polished with diamond-paste finish. Experimental results indicated that improvements in the Curie temperature correlated with the step-induced Pd moments that is supported by the increased surface magneto-optic Kerr effect signal on the stepped surface.

Face-centered cubic Fe was grown onto a novel Cu(110) substrate with ordered Cu-O stripes. Results showed that the growth mode was layer-by-layer and was better than either clean or oxygen-saturated Cu(110). It was postulated that the Fe films grow conformationally onto the original striped substrate. Lateral long-range ordering of the stripe-like structure on Fe was retained up tp 6-7 ML. These films were ferromagnetic with in-plane magnetic anisotropy.

In the field of clean solar-to-current devices, the photoelectron transfer process is essential for photovoltaic conversion in the typical n-i-p solar-cell structure. With regard to the oriented injection and ejection of photoelectrons, the development of hole-blocking layer (HBL) materials with a high electron transfer capability are exceedingly desirable. Profiting from the distortion of the p-π electron cloud attracted by a doped aprotic cation, a modified n-type polyaniline (PANI) as the HBL of a photoanode has been successfully fabricated through a facial one-pot square-wave potentiostatic electropolymerization method. In terms of flat-band potential, charge-carrier concentration and device impedance, the synthesized n-type polyaniline layer doped by aprotic ionic liquid (AIL; [EMIM] [EtSO4]) (AIL–PA layer) for quantum dot solar cells (QDSCs) directly facilitates the high electron carrying capacity as well as the electron transfer driving force. Furthermore, the n-type polyaniline layer doped by AIL ([EMIM] [EtSO4]) (AIL–PA layer) has a widely matching band gap for electron exportation and improved photovoltaic performance of CdSxSe1-x QDSCs: the power conversion efficiency is 10.5% and the Jsc is 21.59 mA cm−2 for the device with an AIL-PA HBL. The electron diffusion length LD is 8.07 μm for the photoanode with AIL-PA I and 7.58 μm for the photoanode with AIL-PA II. [ABSTRACT FROM AUTHOR]