Nanostructured surfaces

Temperature range of helium desorption from austenitic stainless steel 18Cr10NiTi implanted helium at 600 K
V.I. Zhurba, O.V. Mats, V.O. Progolaeva, O. Morozov
NSC-Kharkiv Institute of Physics and Technology of the NAS of Ukraine.
1, Akademichna St., Kharkiv-61108, Ukraine.
E-mail: morozov@kipt.kharkov.ua

Helium thermal desorption spectra were investigated on the samples of austenitic steel 18Cr10NiTi pre-implanted with 24 keV helium ions at current density 5 μA/cm2 in the dose range from 5 × 1016 to 4 × 1018 He/cm2 at the sample temperature Tirr ~ 600 K.
The spectrum of helium thermodesorption from the samples exposed to doses ~ 5 × 1016 He/cm2 represents the temperature-scale smeared region of helium desorption with maxima in the temperature ~1470 K.
The increase in a dose of the implanted helium is accompanied by advancement of a spectrum of allocation of helium in a direction of fall of temperature. For a dose 4×1016 Не/см2 the spectrum helium thermodesorption represents to the area washed away on a temperature scale desorption with badly divided peaks in a range of temperatures 1000 – 1400 K.
At the further increase in a dose of the implanted helium there is a qualitative change of a spectrum thermodesorption the helium, shown in formation of peak to maximum temperature at Tm ~ 1000 K. The further increase in a dose of the implanted helium leads to growth of intensity of this peak of a spectrum thermodesorption and it becomes prevailing.
At doses above 1×1018 He/cm2 the formation of low-temperature regions of helium desorption is accompanied by the appearance of the helium desorption region, extended in the temperature scale in the range between 620 and 850 K. The quantity of the implanted helium is decreases.
Proceeding from representation that atoms of helium in a crystal lattice of a steel form vacancy – helium complexes, peak with temperature of a maximum ~1000 K corresponds to temperature of disintegration of such complexes. Thus the quantity of atoms of helium in a complex is strictly defined. Further energy of activation desorption helium will be calculated, the analysis of the received results of research is offered.