5原子-2剖析.pptx

原子在磁场中的行为：塞曼效应;角动量与磁矩Angular momentum magnetic dipole;磁矩在磁场中：能量;Magnetic dipole in constant B field:;Lx 和 Ly 是量子化的吗? ;?为何只有一个角动量分量是量子化的？;l=1;斯忒恩-盖拉赫实验Stern-Gerlach experiment (1921);(2)H 和 Ag原子有相同的偏转 Ag原子：封闭壳层外的一个s电子 来自内壳层电子的角动量相互抵消;F F F F F f;5893? ;Uhlenbeck Goudsmit (1925) 电子具有内秉角动量( intrinsic angular momentum)! ;Electron spin;Uhlenbeck: “I remember that most of these thoughts came to us on an afternoon at the end of September 1925. We were excited, but we had not the slightest intention of publishing anything. It seemed so speculative and bold, that something ought to be wrong with it, especially since Bohr, Heisenberg, and Pauli, our great authorities, had never proposed anything of the kind.” Ehrenfest: “It was either highly important or nonsense.” “You are both young enough to allow yourselves some foolishness!” ; 电子不是绕自身轴自转！ 自旋是内秉角动量，与角坐标无关 自旋是狄拉克相对论量子力学理论的自然结果; 用4个量子数 来描述原子中电子的量子态 空间运动状态： 自旋态：s(=1/2) ;原子的精细结构 Fine structure;自旋-轨道相互作用 Spin-orbit interaction;相互作用能： ;角动量求和：单电子情形 ;J 根据以下规则量子化：;j=3/2,;? 为何能量不同?;Fine structure in H atom;【例】钠原子D线是双线结构，波长分别为5889.95?和5895.92?，估算在电子轨道运动产生的磁场大小。;【例】钠原子D线是双线结构，波长分别为5889.95?和5895.92?，估算在电子轨道运动产生的磁场大小。;A A A A A K l