Perpendicular magnetization and precise control over the magnetic easy axis in magnetic thin film is necessary for a variety of applications, particularly in magnetic recording media. A strong (111) orientation is successfully achieved in the CoFe2O4 (CFO) thin film at relatively low substrate temperature of 100 °C, whereas the (311)-preferred randomly oriented CFO is prepared at room temperature by the DC magnetron sputtering technique. The oxygen-deficient porous CFO film after post-annealing gives rise to compressive strain perpendicular to the film surface, which induces large perpendicular coercivity. We observe the coercivity of 11.3 kOe in the 40-nm CFO thin film, which is the highest perpendicular coercivity ever achieved on an amorphous SiO2/Si substrate. The present approach can guide the systematic tuning of the magnetic easy axis and coercivity in the desired direction with respect to crystal orientation in the nanoscale regime. Importantly, this can be achieved on virtually any type of substrate.

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For the first time, this work presents a novel room temperature time-effective concept to manipulate the crystallization kinetics and magnetic responses of thin films grown on amorphous substrates.

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The present work is focused on the effect of Fe(3+) replacement by rare earth-Ho(3+) ions and their influence on the properties of MnFe2O4 ferrite. The Ho(3+) substituted MnFe2O4 ferrite samples with chemical formula MnHoxFe2-xO4 were synthesized where substitution concentration of Ho(3+) was 0.0, 0.05, 0.1 and 0.15. The samples were synthesized by the self-ignited sol-gel method using the nitrates of the respective elements. Powder X-ray diffraction, transmission electron microscopy, infrared spectroscopy, vibrating sample magnetometer (VSM) and electrical measurements were employed to characterize the structural, magnetic and electrical properties of these ferrite nanoparticles. The cations distribution between the tetrahedral (A-site) and octahedral sites (B-site) has been estimated by XRD analysis. It is found that substitution of Ho(3+) ions favorably influenced the magnetic and electrical properties. Magnetic measurements were carried out at 77 and 300 K. Saturation magnetization and coercivity increased from 54.57 to 71.6 emu g(-1) and 172 to 766 Oe, respectively, with increasing the Ho(3+) substitution. The change in magnetic properties may be explained with the increase of A-O-B (FeA(3+)-O(2-)-HoB(3+)) super exchange interactions and the anisotropy constant. The electrical properties show that the pure sample has lower resistivity with respect to any Ho(3+) doped one. The conduction mechanism is used to interpret electrical measurements. Results of the presently investigated samples with enhanced saturation magnetization, coercivity and remanence ratio indicate that the Ho(3+) doped MnFe2O4 nanoparticles can be a useful candidate for the application in high density recording media.

The fabrication of nano-/microsized columns and hole arrays on an n-GaAs substrate was carried out using a combination of colloidal crystal templating, electroless plating/two-step catalyzation, and subsequent metal-assisted chemical etching. Using self-assembled polystyrene spheres as a mask, metal particles, specifically Ag and Pd, were selectively deposited at the interspaces between the polystyrene spheres, resulting in the formation of metal honeycomb patterns on GaAs. Ordered GaAs column arrays were then fabricated by the chemical etching of the GaAs originating from the honeycomb-patterned Ag and Pd metals, which acted as etching catalysts. Each metal catalyst resulted in the formation of a characteristic etched structure and etching depth. Pd-etched column arrays exhibited conical structures, while Ag-etched specimens showed slender column structures owing to the anisotropic etching of the GaAs. Moreover, patterned-GaAs slender grooves exhibiting triangular cross sections were fabricated by Ag-assisted chemical etching. To obtain the groove structures, honeycomb-structural polystyrene spheres were used as an etching mask. After the chemical etching of the GaAs, patterned slender grooves were formed. H777) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 132.174.254.159 Downloaded on 2015-03-13 to IP H778 Journal of The Electrochemical Society, 156 ͑10͒ H777-H781 ͑2009͒ H778 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 132.174.254.159 Downloaded on 2015-03-13 to IP

We estimate how well we will know the parameters of solar neutrino oscillations after KamLAND and Borexino. The expected error on ∆m 2 is few per-mille in the VO and QVO regions, few per-cent in the LMA region, and around 10% in the LOW region. The expected error on sin 2 2θ is around 5%. KamLAND and Borexino will tell unambiguously which specific new measurement, dedicated to pp solar neutrinos, is able to contribute to the determination of θ and perhaps of ∆m 2 . The present data suggest as more likely outcomes: no measurement, or the total pp rate, or its day/night variation.