Miwa J A, MacLeod J M, Moffat Antje, McLean A B
Department of Physics, Queen's University, Kingston, Ont, Canada K7L 3N6.
Ultramicroscopy. 2003 Dec;98(1):43-9. doi: 10.1016/S0304-3991(03)00086-X.
It is known that the vibrational spectra of beetle-type scanning tunneling microscopes with a total mass of approximately 3-4 g contain extrinsic 'rattling' modes in the frequency range extending from 500 to 1700 Hz that interfere with image acquisition. These modes lie below the lowest calculated eigenfrequency of the beetle and it has been suggested that they arise from the inertial sliding of the beetle between surface asperities on the raceway. In this paper we describe some cross-coupling measurements that were performed on three home-built beetle-type STMs of two different designs. We provide evidence that suggests that for beetles with total masses of 12-15 g all the modes in the rattling range are intrinsic. This provides additional support for the notion that the vibrational properties of beetle-type scanning tunneling microscopes can be improved by increasing the contact pressure between the feet of the beetle and the raceway.
已知总质量约为3 - 4克的甲虫型扫描隧道显微镜的振动光谱在500至1700赫兹的频率范围内包含外在的“嘎嘎”模式，这些模式会干扰图像采集。这些模式低于甲虫计算出的最低本征频率，有人认为它们是由甲虫在滚道表面粗糙处之间的惯性滑动引起的。在本文中，我们描述了对三种不同设计的自制甲虫型扫描隧道显微镜进行的一些交叉耦合测量。我们提供的证据表明，对于总质量为12 - 15克的甲虫，嘎嘎声范围内的所有模式都是固有的。这为通过增加甲虫足部与滚道之间的接触压力可以改善甲虫型扫描隧道显微镜的振动特性这一观点提供了额外支持。
