We designed, fabricated, and tested for the first time a prototype of nuclear micropower battery with an overall active area about 15 cm 2 consisted in 130 single cells based on Schottky barrier diamond diodes. Diodes selection for the battery assembly was performed on the basis of I-V curves measurements at electron beam irradiation in SEM. A typical energy conversion efficiency of each cell was about 4-6%. To characterize a battery prototype performance, we carried out photovoltaic measurements using different radioisotopes. Under irradiation by 63 Ni source with activity of 5 mCi cm À2 , the output power density of 3 nW cm À2 was obtained. Due to large energy loss of the emitted b particles in source itself, the total battery efficiency was only 0.6%. However, with the longlived 63 Ni isotope, this already gives the battery specific energy of about 120 W Á hr/kg, comparable with the commercial chemical cells. During experiments with high activity 90 Sr-90 Y source, no degradation was observed after 1,400 h of the radiation exposure. The maximum output power density of 2.4 mW cm À2 was achieved using 238 Pu a source. The results display that synthetic diamond is a highly promising material for nuclear microbattery fabrication. A strategy to further cell optimization is also discussed.

An investigation of the growth mechanisms, electronical and structural properties, and field emissions of carbon films obtained by chemical vapour deposition showed that field emissions from films composed of spatially oriented carbon nanotubes and plate-like graphite nanocrystals exhibit non-metallic behaviour. The experimental evidence of work function local reduction for carbon film materials is reported here. A model of the emission site is proposed and the mechanism of field emission from nanostructured carbon materials is described. In agreement with the model proposed here, the electron emission in different carbon materials results from sp3-like defects in an sp2 network of their graphite-like component.

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First, the Al/AlN/Al/Cr/diamond single crystal piezoelectric layered structure has been developed, and its properties have been investigated up to 8 GHz. The peculiarities associated with the influence of piezoelectric film on the Q factor of high overtones of substrate have been pointed out. High Q ∼ 104 has been found at 6–7 GHz band.

Thin film material of oriented multiwall carbon nanotubes was obtained by noncatalytical chemical vapor deposition in a glow-discharge plasma. The film phase composition, surface morphology, and structural features were studied by Raman and electron microscopy techniques. Low-voltage electron field emission of thin film nanotube material was obtained and examined in diode configuration. The I-V curves in Fowler-Nordheim coordinates were linear and the corresponding threshold average field was about 1.5 V/m. The emission current density was up to 50 mA/cm 2 at the field of 5 V/m. The emission site density reached 10 7 cm Ϫ2 at the same value of electric field.

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