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In this work, electrical manipulation of the magneto-optical properties of a cobalt (Co)/carbon (C) heterostructure is demonstrated via reversible voltage (V)-dependent magnetic circular dichroism (MCD) measurements to provide information on its spin-polarized density of states. Complex impedance spectroscopy revealed the occurrence of capacitance effects between Co and C. Suppression of the radial distribution functions of the X-ray absorption spectra and changes in the Raman spectra reveal that charge injection under an applied V results in increased interstitial charge densities. Angle-dependent changes in MCD under an applied V reveal that variations in C–Co hybridization due to charge accumulation are responsible for the observed phenomena.

This study investigated the ultrathin Cu(002) capping nano-island effects on the magnetic characterizations and microstructure of epitaxial FePt(001) films directly fabricated on MgO(001) substrates at the relatively low temperature of 300 °C via electron-beam deposition. The enhancement of the coercivity is attributed to the lowered exchange coupling of FePt magnetic grains that begun from Cu atom behavior of spreading in many directions mainly along grain boundaries due to its lower surface energy than that of pure Fe or Pt. The measurement of angular-dependent coercivity shows a tendency of a domain-wall motion shift toward the rotation of the reverse-domain type upon the thickness of the Cu capping nano-island layer atop the FePt films. The intergranular interaction was clarified by the Kelly–Henkel plot, which indicated that there was strong exchange coupling (positive δM) between neighboring grains in the FePt continuous films without Cu capping nano-islands. On the other hand, a negative δM value was gained when the FePt films were capped with a Cu(002) single layer, indicating that the Cu capping layer can be used to control the strength of intergrain exchange coupling between the adjacent FePt grains and thicker Cu(002) capping nano-islands toward magnetic isolation, thus, there was an existence of dipole interaction in our designed Cu/FePt composite structure of stacked films.

Magnetic properties and structure of sputter-prepared FePd thin films on the glass substrates by underlayering with refractory elements M (M = Nb, Mo, and W) have been studied. The structural analysis shows that FePd films have a (111) preferred orientation. All studied FePd films exhibit in-plane magnetic anisotropy. For single-layer FePd films, the coercivity ( $H_{c})$ and magnetic energy product [(BH) $_{\mathrm {max}}]$ are increased with annealing temperature ( $T_{a})$ and reached the maximum value of 1.3 kOe and 3.8 MGOe in the sample annealing at 600 °C. With the further increase of $T_{a}$ , magnetic properties drop rapidly. Dependence of magnetic hardening on $T_{a}$ can be explained by dominant solid reactions in different region of $T_{a}$ including ordering and grain growth. Interestingly, magnetic properties of L10-FePd are largely improved by underlayering with 5 nm-thick Nb, Mo, and W layers. Both the coercivity and energy product are significantly increased to 1.6 kOe and 4.9 MGOe for M = Nb, 2.5 kOe and 6.4 MGOe for M = Mo, and 3.3 kOe and 8.7 MGOe for M = W, respectively. Structural analysis suggests that this magnetic enhancement is related to both higher ordering degree and refined microstructure.

For CoO overlayers prepared by evaporating Co atoms in an oxygen atmosphere, both the oxidation of the Co atoms at the interface and the segregation of oxygen atoms into the Co surface occur. Parts of Co atoms at the interface become nonferromagnetic and this causes the reduction of Kerr intensity at 300 K. After field cooling treatments, further reduction of the Kerr intensity is detected. The change of the Kerr intensity is an indicator of the pinned magnetic moments. In the case of forming thicker interfacial region, more pinned magnetic moments are observed and result in the larger exchange bias field for CoO on thicker Co/Ge(1 0 0). This tunable pinning provides a practical way of increasing exchange bias field by controlling the thickness of the interfacial region for ultrathin CoO/Co bilayers on semiconductor substrates.

The controllable photoluminescence and wettability of NiFe/ZnO heterostructure bilayer films have been demonstrated by applying an ultrathin NiFe capping layer onto ZnO films by radio-frequency magnetron sputtering at room temperature without introducing any oxygen gas during the deposition process. High quality crystalline ZnO(002) textured films were fabricated at first and displayed a remarkable near-band-edge emission peak located at around 370 nm with a bandgap of 3.35 eV confirmed by room temperature photoluminescence spectra. Once the ZnO films were capped with a single NiFe layer, ranging from 5 to 20 nm in thickness, the intensity of their near-band-edge emission peak decreased and the emission band shifted to 414 nm. On the other hand, the contact angle of the uncapped ZnO film increased from 88° to 101° with the addition of a 10 nm thick NiFe capping layer. This means that the ultrathin NiFe layer acted as a surfactant layer. The surface wettability could be switched from hydrophilic to hydrophobic due to the varied surface free energy caused by the controllable grain morphology of the NiFe/ZnO heterostructures. This work demonstrates that a direct NiFe capping layer can effectively control the optical, surface and magnetic characteristics in NiFe/ZnO heterostructures depending on the bimetallic NiFe thickness and provide valuable multifunctional behaviors for potential novel magnetoelectric applications.

In this paper, a facile fabrication technique called nanosphere lithography combining with two-step reactive ion etching method for patterning honeycomb metallic electrode with high transparency and excellent uniformity is demonstrated. The patterning silver electrode with 15-nm film thickness and 68.6% fill-factor was used as the organic light-emitting diode (OLED) anode, which showed an average transmittance of 77.4% and sheet resistance of 30.7 Ω/□. The current efficiency is 8.35 cd/A for the OLED with patterned silver anode under 100 cd/m2 operation brightness, which was 47% higher than the device with indium tin oxide (ITO) anode. After applying the polystyrene nanosphere to form a photonic crystal array onto the device, the extracted light from organic mode can be further coupled out from device substrate mode. The overall luminous enhancement of the device with the combination of internal honeycomb metallic anode and external photonic crystal array is 115% higher than the traditional ITO-based OLED.

Combined scanning tunneling microscopy and surface magneto-optic Kerr effect studies were employed to study the relation between magnetic properties and the microscopic interfacial structures of ultrathin Co/√3 × √3 − R30°-Ag/Si(111) films. On the top of √3 × √3 − R30°-Ag/Si(111), pure Co clusters formed without disrupting the √3 × √3 − R30° structure of the Ag buffer layer. The great strain due to the large mismatch between Co and the substrate influenced the nucleation of Co atoms to form large clusters. No magnetic hysteresis in the polar configuration was observed for films thinner than 10 monolayers. The easy axis of magnetization was in the surface plane. Capping √3 × √3 − R30°-Ag on top of the Si(111) surface before the deposition of the Co overlayers can efficiently reduce the nonferromagnetic Co-Si compound to zero thickness. For Co coverage between 2.9 and 4.2 monolayers, a lower Curie temperature was observed in ultrathin films. Due to the existence of a smooth interface between Co and the √3 × √3 − R30°-Ag buffer, the coercivity for Co/√3 × √3 − R30°-Ag/Si(111) is smaller than that for Co/Si(111).

Impairment in diabetic wound healing constitutes an enormous biomedical burden. The receptor for advanced glycation end-products (RAGE) expression in the diabetic cutaneous wound may play a key role. However, the relationship between RAGE expression and topical application of anti-oxidant agents with gold nanoparticles (AuNP) in cutaneous diabetic wounds remains unclear. We tested the 3-5 nm AuNP, epigallocatechin gallate (EGCG), and α-lipoic acid (ALA) could change the RAGE expression and be helpful in diabetic wound. The mixture of AuNP+EGCG+ALA (AuEA) significantly attenuated the AGE-induced RAGE protein expression in fibroblasts (Hs68). Topical EGCG+ALA (EA) and AuEA application accelerated wound healing on diabetic mouse skin and decreased the RAGE expression. Vascular endothelial growth factor but not angiopoietin-1 significantly increased after EA or AuEA treatment for 7 days. Angiopoietin-2 significantly decreased at day 7 in AuEA group. Furthermore, immunoblotting of diabetic wound tissue showed significant decrease of CD68 expression from day 3 to day 7. The results suggest that combination of AuNP, EGCG, and ALA significantly accelerated diabetic cutaneous wound healing through angiogenesis regulation and anti-inflammatory effects. Blockade of RAGE by anti-oxidant agents and nanoparticles may restore effective wound healing in diabetic ulcer.

Co and Ta inserted layers with thickness x varied from 0 to 20 nm on the dielectric permittivity of BaTiO3 (60 nm)/Co(x nm)/BaTiO3 (60 nm) (BCB) and BaTiO3 (60 nm)/Ta(x nm)/BaTiO3 (60 nm) (BTB) films fabricated on glass B270 substrates by the reactive sputtering technique was studied. The dielectric constant is around 7.6 for B270 glass substrate and BaTiO3 /B270 film. However, it is rapidly raised up to roughly 84.3-89.4 for BCB, and 75.5-88.2 for BTB samples with the thickness of the Co or Ta inserted layer larger than 2 nm. This large enhancement of the dielectric constant could be explained due to the growth mechanism of the metallic inserted layer from island clusters to continuous layer for samples with x roughly near 3 nm, and the conducting property of the metallic inserted layer. The adding of a Co or Ta interlayer redistributes the interface charges between metal and ferroelectric layers, and that enhances both the intrinsic polarization and its dielectric constant. For the magnetic induced dielectric variation, after comparing the variation of the dielectric properties of both Co and Ta inter layers, the magneto dielectric properties in BaTiO3 /Co/BaTiO3 films are manifested. This magnetic tunability of the dielectric constant is clearly attributed to the magnetic metallic Co layer in the films. From this study, the magneto dielectric properties are manifested in BTO/Co/BTO films and it has the potential for a ferroic sensor application.

The iron nanowires can be fabricated via the process in which sodium borohydride reduces iron salts in external magnetic field. The iron nanowires are found to be covered by passivated layers of iron oxide which prevent the oxidation of iron nanowires. In this process, the boron will include in iron nanowires. The average length and diameter of iron nanowires is around 1.2 micrometers and 60 nanometers, respectively. According to ICP results, the contents of B and Fe are about 1.98 wt% and 87.04 wt%, respectively, in iron nanowires. A wide variety of equipment is used to investigate the morphological, microchemical, and structural characteristics of the newly synthesized iron nanowires ––– e.g., XRD, FE-SEM, HR-TEM, VSM and XANES. XANES analysis indicates the boron in iron nanowires exists in the form of B2O3. The saturation magnetization and the coercive force of iron nanowires are 157.93 emu/g and 9.74 Oe, respectively. In-situ images of synthesized iron nanowires during reduction process in magnetic field are observed by NSRRC transmission X-ray microscope. Thus, this study develop a novel process to produce iron nanowires with large quantitates and can control its length and diameter by various the concentration of precursors for various applications.

Topical applications of antioxidant agents in cutaneous wounds have attracted much attention. Gold nanoparticles (AuNPs), epigallocatechin gallate (EGCG), and α-lipoic acid (ALA) were shown to have antioxidative effects and could be helpful in wound healing. Their effects in Hs68 and HaCaT cell proliferation and in mouse cutaneous wound healing were studied. Both the mixture of EGCG + ALA (EA) and AuNPs + EGCG + ALA (AuEA) significantly increased Hs68 and HaCaT proliferation and migration. Topical AuEA application accelerated wound healing on mouse skin. Immunoblotting of wound tissue showed significant increase of vascular endothelial cell growth factor and angiopoietin-1 protein expression, but no change of angiopoietin-2 or CD31 after 7 days. After AuEA treatment, CD68 protein expression decreased and Cu/Zn superoxide dismutase increased significantly in the wound area. In conclusion, AuEA significantly accelerated mouse cutaneous wound healing through anti-inflammatory and antioxidation effects. This study may support future studies using other antioxidant agents in the treatment of cutaneous wounds. From the Clinical Editor In this study, topically applied gold nanoparticles with epigallocatechin gallate and alpha-lipoic acid were studied regarding their effects in wound healing in cell cultures. Significant acceleration was demonstrated in wound healing in a murine model.

The microstructure and magnetic properties of multilayer [Os(t)/FePt(x)]n films on a glass substrate with a 10 nm Os buffer layer by ion beam sputtering have been studied as a function of the annealing temperatures between 300 and 800 degrees C. Here, t = 0.2, 1 or 5 nm and x varied from 10, 20, 25, 50, to 100 nm with its associated n value of 10, 5, 4, 2, and 1, respectively. No diffusion evidence was found in samples with a thin Os layer and t > or = 1 nm. The average grain size of the multilayer films can be well controlled by both annealing temperature and thickness of the FePt layer by a very thin Os space layer with t > or = 1 nm. The enhancement of H(c) can be understood from the fact that for a FePt film with an Os spacer layers, the increasing number of Os layer will inhibit the grain growth of FePt grains and enriches the grain boundary. We have experimentally demonstrated that even with a very thin 1 nm Os spacer layers, the [Os(t)/FePt(x)]n multilayer films can exhibit good hard magnetic properties and are attractive candidates for ultrahigh density magnetic recording media.

Dielectric permittivity and loss of BiFeO3 (BFO) and 5 mol% lanthanum-substituted BFO [(Bi0.95La0.05)FeO3 or BFO-5% La] ceramics have been carried out as functions of temperature and frequency. A frequency-dependent and broad dielectric shoulder and maximum were observed in BFO and BFO-5% La near 600-700 K. These dielectric responses are likely due to the magnetoelectric coupling while the antiferromagnetic-paramagnetic transition takes place near the Neel temperature. As an approximation, a barrier model with intrinsic barriers B (in temperature unit) every lattice constant a and extrinsic barriers B +Δ every distance d is introduced to describe the low-frequency upturn in dielectric loss in the high-temperature region. Good qualitative fits are obtained for BFO and BFO-5% La. This work suggests that 5 mol% La substitution can enhance dielectric response and considerably reduce electric conductivity.

Room-temperature-deposited FePt thin films with thickness (t) ranged from 5 to 100 nm treated by rapid-thermal annealing (RTA) were studied. With annealing condition of 900°C for 60 seconds at heating rate of 80° C/sec., a metastable phase of FePt was observed in the films with t ≥ 40 nm. The phase is chemically ordered with a face-centered-cubic (fcc) structure. The lattice parameter of it is found identical to the planar spacing of L10 (100). The metastable structure is dominant in the film with t = 40 nm and gradually replaced by L10 phase with increasing t. The fcc phase is soft magnetic with saturation magnetization similar to that of disordered FePt. Drastic changes were also observed in surface morphology. The results infer the connection between the metastable transformation and internal strain. The formation of the fcc structure is sensitive to processing parameters except t . Slower heating rate, lower annealing temperature, and longer annealing time, tend to suppress the formation of it. The interesting findings provide additional knowledge for FePt thin films.

Development of (001) texture in FePt thin films deposited on glass substrates with different thickness (t) treated by rapid thermal annealing (RTA) is studied. A critical thickness of 30 nm is characterized: below which the (001) preferred orientation of the films develops with increasing t ; when t >; 30 , the films become isotropic. Remarkable perpendicular anisotropy in magnetic properties is achieved in the 30 nm thick sample with the best (001) texture. Discontinuous changes are also observed in surface morphology, microstructure, magnetic domain structure, and internal stress. Direct evidences are presented relating the formation of (001) texture to abnormal grain growth. The internal stress/strain analysis indicates that the residual tensile (σ) stress is proportional to the degree of (001) preferred orientation. A large value of σ of about 8.9 GPa is obtained in the film with t = 30, suggesting the driving force forming the texture.

For Co/Si(111) films thinner than 15 ML, the thickness dependent reactivity and magnetic properties have been systematically studied. As the Co coverage increases, Co adatoms on the Si(111) surface show enhanced chemical reactivity for oxidation due to the change of the chemical state. After the saturation oxygen exposure, oxygen atoms interact with a thick Co layer to form a rougher interface. Complex adsorption kinetics of oxygen in the Co layer is observed. From the depth-profiling measurements for Co layers close to the Co–Si interface, the sputtering rate is enhanced due to that the solid surfaces of Si and Co–Si compounds are resistive against oxidation. The descending of the Kerr intensity by saturation oxygen exposure shows the limited diffusion length of oxygen atoms into the films. The inertness of the Co–Si interface, the reduction of pure cobalt and imperfection introduced by oxygen influence the coercivity of O/Co/Si(111).

Ta-seeded and un-seeded layers of a top-configuration Co/IrMn system were deposited onto glass substrate by DC sputtering. Three sets of deposition conditions for Co(50 A)/IrMn( t IrMn A) and Co( t Co A)/IrMn(90 A), where t IrMn = 15, 30, 60, 90, 110, and 150 A, and t Co = 15, 25, 50, 75, 100, 125, and 150 A, were: condition (a) substrate temperature ( T s ) was kept at room temperature (RT). Condition (b) T s set to RT, with in-plane magnetic field, H = 500 Oe. In condition (c), condition (b) was followed by post-deposition annealing in the magnetic field at T A = 250 °C for 1 h, then field cooled to RT. X-ray diffraction (XRD) patterns and grazing incidence scans revealed maximum IrMn (1 1 1) texture to occur for post-deposition annealed Ta seed layer samples. The IrMn (1 1 1) texture-effect significantly influences magnetic properties, including exchange-biasing field ( H ex ), interfacial energy ( J k ), and coercivity ( H c ). The Ta seed layer also significantly influences magnetic properties. Adding a Ta seed layer to the Co/IrMn system increases H ex , because of the IrMn (1 1 1) texture. For Ta-seeded Co/IrMn under condition (c), H ex tended to saturate for t IrMn ≥ 90 A. Under conditions (a) and (b), H ex decreased with increasing t IrMn for t IrMn ≥ 90 A. H ex values for all un-seeded Co/IrMn systems increased with t IrMn . J k versus t IrMn plot is proportional only to H ex in the Ta-seeded and un-seeded layers of a top-configuration Co/IrMn system, due to the interfacial energy formula, t Co is fixed, and saturation magnetization ( M s ) of the Co layer is constant. Results for the Ta-seeded system showed a strong relationship between H c and t IrMn , due to coupling-decoupling interactions between Co spin, and IrMn layers close to the Co/IrMn interface. The H ex versus t Co result shows that the H ex is proportional to (1/ t Co ). The H ex values with the Ta seed layer are almost slightly larger than those without a Ta seed-layer. The dependence of J k on t Co is similar to the trend in M s on t Co , J k tends to saturate slowly as t Co increases. Surface pinning occurred in all systems, revealing an inverse relation between H c and t Co . Removing the Ta seed-layer weakens IrMn (1 1 1) texturing, reducing H ex . The maximum observed H ex and J k values were 205 Oe and 0.11 erg/cm 2 , respectively.

Magnetic properties and growth mechanism of ultrathin Co films on Si(111)-7 x 7 surface have been studied by using both surface magneto-optic Kerr effect (SMOKE) and scanning tunneling microscopy (STM), respectively. STM results show that the growth mechanism of ultrathin Co films on Si(111)-7 x 7 surface at room temperature belongs to Stranski-Krastanov (SK) growth mode. Due to formation of CoSi2 layer, no magnetic signal could be detected by SMOKE for 1-4 ML Co deposited on Si(111) surface. Because of rougher surface, both longitudinal and perpendicular magnetic anisotropy configuration appear for 4.2-10 ML Co/Si(111) films. When the Co thickness is increased to 10 ML, only longitudinal anisotropy configuration is found, resulting from the contribution to the volume anisotropy. Furthermore, in-plane coercivity increases with Co coverage because of enhancement of ferromagnetic coupling with Co thickness, out-of-plane coercivity increases with Co coverage due to the increment of demagnetized field, induced by the rougher Co surface and pinhole structures.

Co inserted layer with different thickness on the permittivity of Ta2O5(60 nm)/Co(x nm)/Ta2O5(60 nm) trilayer films fabricated on the B270 glass substrates by the reactive sputtering technique was studied. The variation of dielectric constant of the samples is dependent on the thickness of the Co inserted layer observed from 1 kHz and 30 MHz. The dielectric constant of the Ta2O5(60 nm)/Co(x nm)/Ta2O5(60 nm) thin films was varied roughly from 7.9 up to 90.6 with the thickness (x) of the Co interlayer varied from 0 nm to 20 nm. The value of the dielectric constant is roughly near 7.9 for samples with x between 0 and 2 nm. However, it increases abruptly for samples with x larger than 2 nm, this large enhancement behavior of the dielectric constant could be explained due to the growth mechanism of the Cobalt inter-layer from island clusters to continuous Co layer for samples with x between 2 and 3 nm. For the magnetic induced ferroelectric variation, the variation of the dielectric constant increased with thickness of Co for samples with x larger than 3 nm. However this increase behavior is roughly saturated for applied magnetic field roughly above 20 Oe. This magnetic tunability of the dielectric constant is clearly attributed to the Co layer in the films. From the electric consideration, the adding of a Co inter-layer in Ta2O5/Co/Ta2O5 structures redistributes the interface charges between Co and Ta2O5 layers, and that enhances both the intrinsic polarization and its dielectric constant. The magnetoelectric properties in Ta2O5/Co/Ta2O5 films are manifested and it has potential for a ferroic sensor application.

Magnetization, grain size, x-ray diffraction, and dielectric permittivity of BiFeO3 (BFO) and 5 mol% lanthanum-substitution BFO [(Bi0.9BLa0.05)FeO3] ceramics have been carried out as a function of sintering temperature (910-950°C) BFO ceramic exhibits an antiferromagnetic behavior, whose magnetization curve is linear with the field at room temperature. A weak ferromagnetic behavior occurs in (Bi0.9BLa0.05)FeO3 (BLFO) ceramics at room temperature, in which remanent magnetization increases from 0.008 to 0.14 as sintering temperature raises from 910 to 950°C. This phenomenon can be correlated with the growth of grain size of BLFO ceramics, which grows with increasing sintering temperature. The dielectric permittivities of BFO and BLFO are about 33 and 57 at room temperature, respectively. The dielectric losses (tan δ) of BFO and BLFO ceramics vary respectively in the ranges of ~0.2-0.4 and ~0.002-0.004 below 150°C, indicating that 5 mol% La-substitution can efficiently reduce electric conductivity. A frequency-dependent and broad dielectric maximum was observed in both BFO and BLFO ceramics upon heating. This dielectric response is likely triggered by the antiferromagnetic-paramagnetic transition near the Neel temperature.

Magnetization, grain size, structure, and temperature-dependent dielectric permittivity of BiFeO3, (BiFeO3,0.95(BaTiO3)0.05 -(BaTiO3)0.05(5%BTO-BFO), and (Bi0.95Ba0.05)(Fe0.95Ti0.05)O3[5%(Ba, Ti)-BFO] ceramics have been carried out. BFO and 5%BTO-BFO exhibit an typical antiferromagnetic behavior, whose magnetization curve is linear with magnetic field at room temperature. The magnetic hysteresis loop of 5%(Ba,Ti)-BFO ceramic shows a weak ferromagnetic behavior with a small remanent magnetization of about 0.01 emu/g possibly due to a higher density in the grain matrix. This result also implies that the A-and B-site substitutions with Ba2+ and Ti4+ could efficiently suppress the spiral magnetic modulation. The magnetic susceptibilities of BFO, 5%BTO-BFO, and 5%(Ba,Ti)-BFO ceramics are about 1.9 × 10-5, 5.43 × 10-6, and 8.67 × 10-6 emu/gOe, respectively. Frequency-dependent dielectric maxima were observed in BFO, 5%BTO-BFO, and 5%(Ba,Ti)-BFO ceramics upon heating. This dielectric response is likely triggered by the antiferromagnetic-paramagnetic transition near the Neel temperature.

The surface of poly(methyl methacrylate) (PMMA) was treated by plasma with an end-Hall ion source in vacuum in order to enhance its anti-reflectivity. The cone-shaped bumps induced by the plasma etching have shown an antireflective effect. Moreover, PMMA has poor thermal durability due to its low melting point; therefore, the etched PMMA was further coated by a 5 nm thick SiO2 film after 900 and 1300 s plasma etching. Samples after SiO2 coating were thermally annealed at temperature of 70°C for 1 h. Experiments show that transmittance was increased after 5 nm thick SiO2 coating. The of transmittance of PMMA after both sides treated by 900 s plasma etching and 5 nm SiO2 coating was not changed after thermal annealing. However, without SiO2 coating the transmission was reduced 1% after annealing. Atomic force microscope (AFM) demonstrated that the nano-structures of cone-shaped bumps were formed on the PMMA after plasma etching and a smoother nano-structured pattern preserved the transmittance of the PMMA after both sides treated by 900 s plasma etching and 5 nm SiO2 coating. Three dimensional photonic crystal formed by uniformly distributed cone-shaped bumps was assumed to result in the reduction of the anti-reflectivity of treated PMMA.

Co nanoislands on the Au(111) and Cu(111) surfaces have been studied by scanning tunneling microscopy and spectroscopy. The experimental results showed that Co nanoislands prefer to aggregate at the step edge and dislocation sites on the reconstructed Au(111) surface and at the step edge on the Cu(111) surface, respectively. In addition, based on dZ/dV-V spectra, in both the Co/Au(111) and the Co/Cu(111) systems, Gundlach oscillation was observed. From the peak shift of dZ/dV-V spectra between Co nanoisland and substrate surface, we can quantitatively obtain that the constant energy separation is -0.13 +/- 0.01 eV for the Co/Au(111) system, and 0.41 +/- 0.02 eV for the Co/Cu(111) system, respectively. These values indicate the work function difference between Co nanoisland and these surfaces.

Periodic Ag line arrays with different line pitches from 500 nm to 950 nm on ITO coated glass substrates have been fabricated by using electron-beam lithography (EBL) technique for studying the color light guide in a display system. The patterned Ag line array is used as a light outcoupling and color-selection component due to the emission wavelength changed by the Ag line arrays with different periodic distances that could achieve color variation. We have demonstrated that the ITO coated glass substrates containing periodic Ag line arrays with varied line pitches can be used as a color filter in a display device. This means that with a proper metallic nanostructure layer, the red, green, and blue colors in a display system can be obtained without a traditional color filter for modern multi-applications of optoelectronic display devices.

Vertically aligned Fe arrays have been self-assembled on anodic aluminum oxide templates by evaporation. The rims of the pores, which act as obstacles to the stacking of atoms, prevent them from forming continuous films. By controlling the Fe nominal thicknesses (τ n ) from 400 to 5 nm, the morphology is changed from continuous film to isolated arrays, leading to the change of the predominant magnetization reversal from domain wall motion to spin rotation. For samples with τ n

A method observing both radial and axial vibrations of time domain and frequency spectrum was studied to investigate the axial load effect of a flat-type brushless dc fan motor operating with and without the rated axial thrust force. When the developed small motor does not exhibit an intrinsically excited unbalanced magnetic force (UMF), the axial force leads to a minor contribution to the growth of the axial vibration. However, when the UMF is intrinsically excited, the preload can enormously decrease the undesired axial vibration. The ratio of the axial vibration of the prototype with the asymmetric magnetic sheet to the one without the sheet is experimentally observed around 55 percent. It demonstrates that axial load plays an effective and crucial factor in controlling the axial vibration of the mobile fan motor.

By making use of the dc magnetron sputtering system, the Au/FePt bilayers have been prepared on glass substrates and anodized aluminum oxide (AAO) membranes with an average pore diameter of around 200 nm. In both cases, the FePt films can be converted into the magnetically hard phase, namely L1 0 phase, after a heat treatment above 500 °C for 1 h. A nanoparticle-like structure can be observed in the 15-nm-thick FePt film on the AAO membrane. The experimental observations of the structure and the magnetism of the FePt films on the AAO membranes are firstly established.

Ordered FePt continuous thin films with an amorphous SiO2 single capping layer have been fabricated on MgO (001) single-crystal substrates by the electron beam deposition technique at 400degC in order to investigate the effects of SiO2 capping layer on microstructure and magnetic reversal process of the FePt (001) thin films. The formation of nanogranular-like FePt films was directly obtained with this process due to the interpenetration of SiO2 which has a lower surface energy than that of pure Fe or Pt. Studies of angular dependent coercivity show a tendency of a domain-wall motion weaken towards rotation of reverse-domain type upon thickness of SiO2 capping layer on the FePt thin films. The intergrain interaction was confirmed from the Kelly-Henkel (deltaM) plot that indicated the strong exchange coupling between neighboring grains in the FePt continuous films without SiO2 capping layer. On the other hand, negative deltaM value was obtained when the FePt films with SiO2 capping layer, indicating the SiO2 capping layer, can lead to the reduction of intergrain exchange coupling thus presence of dipole interaction in the SiO2/FePt nanocomposite thin film structures.

In situ X-ray diffraction of BiFeO3 (BFO) ceramic and thin film has been carried out as a function of temperature (25degC-900degC) upon heating. The BFO thin film was deposited on Pt/TiOx/SiOx/Si(100) substrate by radio-frequency magnetron sputtering at 650degC. BFO thin film exhibits a structural transformation from rhombohedral to cubic in the region of 700-750degC upon heating. The magnetic property of BiFeO3/Co/BiFeO3 multilayer structure changes from diamagnetic to ferromagnetic phases with increasing thickness of Co layer. The dielectric permittivities (real and imaginary parts) of BiFeO3 ceramic exhibit a frequency-dependent relaxation-like behavior and its magnitude (real part) is higher than 1000 for f les 1 MHz. Surface morphology shows that the root-mean-square roughness of BFO thin film varies with sputtering power.

A structure characterization of chromium-substituted lithium ferrite specimens was carried out by the X-ray diffraction technique and found that the lattice parameter decreases with increasing of Cr-substitution content and the microstructure was determined by scanning electron microscopy (SEM), which revealed that the average grain size of chromium-substituted lithium ferrite decreases gradually with increasing Cr-substitution content. The magnetic moments calculated from Neel's molecular field model are in agreement in the experiment result, which indicates that the saturation magnetization decreases monotonically with increasing Cr-substitution content. The values of saturation magnetization (Ms) for Li 0.5 Fe 1.5− x Cr x O 4 specimens decrease from 38.9 emu/g for x = 0.0 to 9.9 emu/g for x = 1.0. The microwave properties (complex permittivity and permeability) were measured in the 8–13 GHz frequency range by the cavity perturbation. The systematic variations of the real and imaginary parts of both permittivity and permeability with frequency and composition have been analyzed. The real and imaginary parts of both permittivity and permeability values decreased gradually with increasing frequency. The real part of permittivity ɛ ′ values are found to vary in the range of 15.44–12.37, and the real part of permeability μ ′ values are found to vary in the range of 3.95–1.27.

Influences of oxygen exposure on the magnetic properties of Co/Ge(1 1 1) ultrathin films have been investigated by surface magneto-optic Kerr effect technique. As the oxygen exposure increases on Co/Ge(1 1 1) films, their magnetic properties could be modified. As an example for 15 ML Co/Ge(1 1 1) films, the coercivity increases from 730 to 920 Oe and the remanence Kerr intensity is reduced for 500 Langmuir (L) of oxygen exposure. Corresponding compositions analyzed by Auger electron spectroscopy measurement shows that the amount of oxygen on the surface layers increases with increasing the oxygen exposure time. Oxygen distributes on the topmost layers of the film. The adsorbed oxygen influences the electronic density of states of Co and results in the changes of the magnetic properties. Besides, the appearance of O/Co/Ge interface could modify the stress anisotropy, and as a result the coercivity of ultrathin Co/Ge(1 1 1) film is enhanced.