第二讲探针显微镜.ppt

硅的机械刻蚀 适合样品： Advantages: 较高的分辨力 (1 to 5nm) 较小的力，不损坏较软的样品 消除了切向力 Disadvantages: 和AFM相比，扫描速度稍慢 Q curve Phase detection refers to the monitoring of phase lag（相位滞后） between the signal that drives the cantilever to oscillate and the cantilever oscillation output signal. Viberational Signal: Φ1 Detector Signal: Φ2 ΔΦ=Φ1 -Φ2 Phase 像显示deg数据，同选择的工作点无关。 Phase模式的应用 应用于污染物的检测，复合物的区别，粘附力和硬度大小的区分。 Simultaneously acquired (left) Topo and (right) phase images of genomic DNA from the lambda bacteriophage scanned in air on a mica substrate. Due to a thick contamination layer on the sample, the DNA could be visualized clearly only in the phase image. Contrast in the phase image is due to the viscoelastic properties of the DNA on the mica. 3250nm scan. 集成电路的焊盘 Contamination 1.5 micron scan Tapping Mode AFM topo (left) and phase (right) images simultaneously recorded for the surface of polydiethylsiloxane(PDES聚二乙基氧硅烷) deposited on Si substrate by rubbing. 4000nm scan. MoO3 crystallites on a MoS2 substrate 6 micron scan Fluid Tapping Mode image of positively charged polystyrene latex particles adsorbed to mica in water. The average particle diameter is 120nm. 3000nn scan. 二次扫描：接触或轻敲模式 轻 敲 模 式：首先通过一般轻敲模式测量得到样品的表面形貌 ，记录这一次的扫描轨迹。第二次扫描时，探针提升到一定的高度, 完全 沿着第一次扫描的轨迹扫描。 接 触 模 式： 探针首先同样品接触，监测探针和样品间的短程原子间斥力，进行通常的AFM扫描轨迹，得到形貌。然后，探针提升一定的高度（100nm）沿着第一次扫描路线的轨迹不变。 二次扫描模式主要应用于磁力显微镜、静电力显微镜和开尔文探针显微镜等等。 磁力显微镜（MFM) 第二次扫描时测量相位或振幅的变化，得到表面磁畴分布的信息。 硬盘 探针与样品间作用力，探针半径，有机分子的HOMO-LUMO结构，分子和基底电极的接触电阻等等。 The sketch map of the LB film structure The chain of AA is longer than that of SA(OA), the top of the fatty chain is scraggy. And the C60 molecules stay on the top of the fatty chain. The sketch map of the C60/CdS composite C60:AA:SA:OA=2:3:3:4 After H2S sulfureted hydrogen CdS---n-Si I/V curve at point 1, with light the current began to rise at low negat