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Reducing the size of a superconductor below its characteristic length scales can either enhance or suppress its critical temperature (Tc). Depending on the bulk value of the electron-phonon coupling strength, electronic and phonon confinement effects will play different roles in the modification of Tc. Experimentally disentangling each contribution has remained a challenge. We have measured both the phonon density of states and Tc of Sn nanowires with diameters of 18, 35, and 100 nm in order to quantify the effects of phonon confinement on superconductivity. We observe a shift of the phonon frequency towards the low-energy region and an increase in the electron-phonon coupling constant that can account for the measured increase in Tc.

A large enhancement of the magnetic anisotropy of Ni nanowires (NWs) embedded in anodic aluminium oxide porous membranes is obtained as a result of an induced magnetoelastic (ME) anisotropy contribution. This unusual large anisotropy enhancement depends on the diameter of the NWs and exceeds the magnetostatic (MS) contribution. As a consequence, it leads to effective magnetic anisotropy energies as large as 1.4 ´ 106 erg cm−3, which are of the same order of magnitude and comparable to the MS energies of harder magnetic materials like Co NWs. Specifically, from ferromagnetic resonance experiments, the magnetic anisotropy of the NWs has been observed to increase as its diameter is decreased, leading to values that are about four times larger than the corresponding value when only the MS anisotropy is present. Our results are consistent with the recently proposed growth mechanism of Ni NWs that proceeds via a polycrystalline stage at the bottom followed by a single-crystalline stage with texture [110] parallel to the axis of the NWs. A strong correlation between reducing the diameter of the NWs with the decrease of the length of the poly-crystalline segment and the enhancement of the effective magnetic anisotropy has been shown. Magnetization curves obtained from alternating gradient magnetometry experiments show that the average ME anisotropy results from the competition between the magnetic anisotropies of both crystalline segments of the NWs. Understanding the influence of size and confinement effects on the magnetic properties of nanocomposites is of prime interest for the development of novel and agile devices.

A reliable and flexible synthesis route was used for processing high density Ni–BaTiO3 nanocable arrays based on wet chemical impregnation and subsequent electrodeposition within a highly ordered unidirectional porous alumina membrane. The core–shell structure was carefully investigated by bright field scanning transmission electronic microscopy coupled with energy dispersive X-ray spectroscopy. The strength of the dipolar interaction arising from the packing density of the magnetic nanowires was correlated with the BaTiO3 wall thickness through magnetometry and ferromagnetic resonance measurements. Our approach opens a pathway to obtain optimized nanostructured multiferroic composites exhibiting tunable magnetic properties.

A short series of 4-nitro-N-phenylbenzamides was synthesized and evaluated for anticonvulsant properties and neurotoxicity. In mice dosed intraperitoneally, three of the four 4-nitro-N-phenylbenzamides were efficient in the maximal electroshock-induced seizure (MES) test, especially N-(2,6-dimethylphenyl)-4-nitrobenzamide (EDS, value in the MES test = 31.8 mu mol/kg, TD,, = 166.9 mu mol/kg, protective index [PI] = 5.2) and N-(2-chloro-6-methylphenyl)-4-nitrobenzamide (ED(50) value in the MES test = 90.3 mu mol/kg, TD50 = 1.068 mu mol/kg, PI = 11.8). The latter 4-nitro-N-phenylbenzamide was also found to be active against seizures induced by subcutaneous pentylenetetrazole (sc Ptz) and was selected for further evaluation in rats dosed orally. In these conditions, N-(2-chloro-6-melhylphenyl)-4-nitrobenzamide was found to be, in the MES test, three times more active than phenytoin and 4-amino-N-(2,6-dimethylphenyl)benzamide, two potent anti-MES agents.