The Behavior Of 3d Electrons And Its Effect On The Properties Of Alluminide Intermetallic Compounds

The behavior of 3d electron and its effect on the properties of alluminide intermetallic compound and Ni-Cr-Co alloys have been studied by using the Doppler broadening of positron annihilation radiation technique. The Doppler broadening spetra were measured by two-detector coincidence system, and the background of the spectrum can be reduced remarkably, with a peak to blackground ratio of about 1.5 ×10~4, which allows obtaining the contribution of annihilations with core electrons.The 3d electron signal for the transition metals (Ni, Cr, Co) and the Ni-Cr-Co alloys with different Co content can be extracted from Doppler broadening spectra of positron annihilation radiation. The detailed shape of the high-momentum part of the Doppler spectrum depends on the probability of the positron annihilation with the 3d electrons of the atom. In the case of the ratio curves of Ni, Cr, Co metals, with the increase of the 3d electrons (Cr, 5; Co, 7; Ni, 8), the peak position of ratio curve moves toward higher momentum, and the heigh of the peak increases. The bonding nature in Ni-Cr-Co alloys is metallic, and the Ni-Cr-Co alloys shown good ductility.