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The physical and chemical interaction processes in thin film arrangements are followed by different ageing phenomena which influence the stability of their physical paramet.ers. These determine the reliability of the electronic components existing of thin films.On the base of own experimental investigations on tantalum and its oxides, beryllium oxide and tantalum-rhenium alloys tcchnological aspects and the application of new materials for lowering the ageing intensity are considered. @H3HqeCKOe U XIlMMqeCKOe B3aHMOAefiCTBHe B TOHKHX IIJIeHKaX npHBOnHT K pa3JIU' IHbIM (PeHOMeIIaM CTapeHHH, KOTOpbIe BJIHIIIOT Ha CTa6HJIbHOCTb UX (PH3H-YeCKHX 11apaMeTpOB. 3Ta CTa6HJlbHOCTb 0603HaYaeT Hank-KHOCTb 3JleKTPOHHblX npH60pOB, KOTOPbIe COCTORT M 3 3TMX TOHKMX llJleHOK. OKHCJla 6epHJIJIHH H CllJlaBOB TaHTaJla H PeHHfl , aBT0pbI.e PaCaMaTpHBaIOT MeXHO-Ha ocHoBe CBOHX 3IiClIepHMeHTaJII,HbIX mcnexoBaHnZi TaHTaaa EI ero OKEICJIOB, norwiecme acneKTbI H npwMeneHue H O P~I X MaTepaanon n m noHumeHm HHTeH-CHBHOCTH npoueccoe cTapeam.

A Method for PreparinP Sphere-Shaped Single Crvskals of High Melting Metals Without Crucible For the investigation of different directed crystal properties sphere-shaped single crystals have proved to be useful. Crucible methods are not qualified for the manufacture of monocrystals of high melting metals or their alloys. Sphere-shaped monocrystals can be turned off from cylindrical ones (PAWEL, CATHCART, CAMPBELL). Apart from the fact that this method fails, e.g. for the very hard metals molybdenum and tungsten, an additional chemical treatment and a subsequent vacuum tempering are required, if an originally uncontaminated surface of a crystal with high quality is wanted (STRINGER).A method is developed enabling sphere-shaped single crystals to be produced without crucible and subsequent treatment: Wire-or rod-shaped basic material is fixed vertically on one end in a high vacuum chamber (residual gas pressure lower than 5possible) in such a manner that the Free lower end can be heated up to the melting temperature by means of electron impact (ring-shaped tungsten cathode; specimen as anode), whereby a drop ist formed hanging on the spccirnen. The heating power being switched off, the drop solidifies sphere-shaped and monocrystalline.A s an example Figure 1 shows the structure of a tantalum specimen in a micrograph.mm Hg,if Fig. 1. A monocrystalline sphere of tantalum on a rod-shaped specimen after polishing and etching (vertically shortened by micrograph montage)Below a smooth, electrolytically polished surface of the monocrystalline sphere with the adjacent rod region is to be seen, electrolytically etched and thus rendering visible the recrystallization structure. Above the fibre structure of the cold-drawn basic material 4 mm in diameter is shown. Etching the monocrystalline surface an etch pit density of 6 -106 cm-2 was obtained. -Occasionally spheres are formed containing two o r more crystallites.specimens of different size. Likewise the method is suitable for alloys.Sphere-shaped single crystals were also prepared from tungsten, niobium and zirconium

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