the energy of point A with the wave vector close to the border of the Brilluion zone,is decreased due to the influence of perturbation effect,and the energy surface protrudes toward the border. the energy surface is no longer a whole enclosed surface between the point A and C,but a curved surface disengaged around the apexes
—— the energy of point A with the wave vector close to the border of the Brilluion zone, is decreased due to the influence of perturbation effect, and the energy surface protrudes toward the border. —— the energy surface is no longer a whole enclosed surface between the point A and C， but a curved surface disengaged around the apexes
亿 The change of the DOS N(E)=lim E with the k approaching the border of the Brilluion zone,the energy surface protrudes toward the border gradually,and the volume between these two energy surfaces become larger,and hence the DOS is enhanced marginally. Between point A and C,the energy surface is splitted.At point C,the energy surface shrinks to a point -The DOS is reduced to be zero XCH004037 E↑ Near-free electron model EA N(E)
The change of the DOS with the k approaching the border of the Brilluion zone, the energy surface protrudes toward the border gradually, and the volume between these two energy surfaces become larger, and hence the DOS is enhanced marginally. Between point A and C， the energy surface is splitted. At point C, the energy surface shrinks to a point —— The DOS is reduced to be zero. E Z N E ( ) = lim
The DOS in the second Brilluion zone when E surpasses the pint A in FBZ,the DOS will rapidly increase from zero. E↑ EA EA Band Without overlapping overlappiing Ec>E8 N(E) Ec<EB N(E)
The DOS in the second Brilluion zone —— when E surpasses the pint A in FBZ, the DOS will rapidly increase from zero