Effect of Xe ion irration of Fe/Sn bilayers

Films of Fe (20 nm) and Sn (40 nm) have been deposited by PVD onto Al supports and irradiated with 100 keV Xe ions at a dose of 5×10¹⁵ ions/cm². Scanning electron microscopy (SEM) shows that the irregular morphology of deposited Sn is considerably flattened by irradiation, which produces also a noticeable sputtering of Sn. Conversion electron Mössbauer spectroscopy (CEMS) reveals the formation at the interface of a variety of intermetallic phases which is enhanced by irradiation. These phases, seem to be insensible to prolonged (several months) room temperature aging. Their thermal stability under annealing at temperature up to 523 K has also been investigated.     

Effective temperature in the impact surface region during 100 keV Xe+ implantation of copper bars

The temperature evolution of a copper bar during 100 keV Xe ions implantation has been experimentally recorded. The thermal behaviour of the implanted bar is quantitatively described by a simple model calculation. It is shown that the experimental results may be reproduced by considering a radiative energy dissipation from hightemperature surface regions intersected by ion impact. The quantities characterizing these thermal-spike regions like average temperature and lifetime are consistent with earlier thermodynamical estimations reported in the current literature.     

Rho(0) meson production in the pp-->pppi(+)pi(-) reaction at 3.67 GeV/c

Total and differential cross sections for the exclusive reaction pp-->pp rho observed via the pi(+)pi(-) decay channel have been measured at p(beam)=3.67 GeV/c. The observed total meson production cross section is determined to be (23.4+/-0.8+/-8) mu b and is significantly lower than typical cross sections used in model calculations for heavy-ion collisions. The differential cross sections measured indicate a strong anisotropy (approximately cos(theta(CM)(rho)) in the rho(0) meson production.     

119Sn conversion electron Mössbauer study of Fe/Sn bilayers irradiated by Xe ions

The effect of Xe⁺ irradiation and that of subsequent annealings on Fe/Sn bilayer have been studied by¹¹⁹Sn conversion electron Mössbauer spectroscopy. It seems that the effectiveness of ion-beam mixing is comparable to the thermal treatment of the bilayer.     

Comparative Study of Electrodeposited and Ion Beam Mixed Fe-Ni-Cr Alloys

Electrodeposited Fe-Ni-Cr alloys irradiated with 209 MeV energy ⁸⁴Kr ions were investigated by conversion electron Mössbauer spectroscopy, X-ray diffraction and electron microprobe analysis. Significant dose dependent changes were found between Mössbauer spectra of the irradiated and non-irradiated deposits. These changes reflect the dose dependent transformation of the metastable ferromagnetic phase to the paramagnetic one.     

Mössbauer study of some ion-beam irradiated Co−Sn electrodeposits

The effect of ion-beam irradiation on the composition and structure of some Co–Sn electrodeposits has been studied by Mössbauer spectroscopy. A transformation of dissolved tin and cubic CoSn to -Co₃Sn₂ was observed.     

Partial breakdown of the evaporation model and possible preequilibrium α-particle emission in heavy-ion fusion reactions

Relative cross sections for residual nuclei following fusion reactions were measured by γ-ray spectroscopy in the reactions ⁵²Cr+ ¹²C at 56.00 MeV and ⁴⁸Ti+ ¹⁶O at 57.74 MeV, in which the common “compound nucleus” ⁶⁴Zn was excited at the same energies and the relative distributions of the entrance spins were nearly identical. It is shown that ratios of the measured cross sections in both entrance channels can be precisely determined experimentally and are insensitive to small changes of the parameters in calculations based on the evaporation model. Using these particular quantities, we have shown that the evaporation process is not the sole mechanism producing the observed residues, especially those resulting from α-particle emission. The assumption of preequilibrium α-particle emission at high channel spins is shown to reproduce the present data fairly well.     

Ion beam induced phase transformation in Fe–Mn bilayers: a Mössbauer study

Ion‐beam mixing of Fe–Mn bilayers induced by 100 keV krypton ions in the dose range (0.1-15)×10¹⁵ ions/cm²has been studied by means of conversion electron Mössbauer spectroscopy and X‐ray diffraction. The results indicate that a dose of about 1 ×10¹⁵ Kr⁺/cm² is sufficient to induce an appreciable mixing between the two atomic species. The α-Fe(Mn)solid solution presents a maximum at this dose, while at higher doses also the ? and γFe–Mn phases are formed in an appreciable amount. Heating of irradiated samples evidences the metastable character of ? phase and favours the growth of the terminal structures γ-Fe(Mn) and α-Mn(Fe) of the Fe–Mn equilibrium phase diagram.