【摘要】 测量了Al,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Ga等金属的正电子湮没辐射Doppler展宽谱.采用双探头符合技术,可大幅度地降低谱线的本底,并获得正电子与原子内层电子湮没对谱线的贡献.实验结果表明:谱线的本底随样品与高纯Ge探头之间距离的增加而减小;Ni的商谱(以单晶Al为参考)的谱峰随谱线本底的降低而升高;元素周期表中第四周期的Ti,V,Cr,Mn,Fe,Co,Ni,Cu金属的商谱的谱峰随原子的3d电子数目的增多而升高.更多还原

【Abstract】 Doppler-broadening spectra of positron annihilation radiation of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ga have been measured by using 2-detector coincidence technique. The lower background of the spectrum allows to obtain the contribution of annihilations with core electrons. The experiments show that the background decreases with increasing the distance between the sample and the Ge detector. The magnitude of the peak of the ratio curve of Ni (ratio to Al) increases with decreasing the background of the spectrum. For Ti, V, Cr, Mn, Fe, Co, Ni and Cu, the heights of the peaks in the ratio curves rise with increasing the number of 3d-electrons.更多还原