Danışman M Fatih, Özkan Berrin
Department of Chemistry, Middle East Technical University, Ankara 06800, Turkey.
Rev Sci Instrum. 2011 Nov;82(11):115104. doi: 10.1063/1.3658819.
We describe a quartz crystal microbalance setup that can be operated at low temperatures in ultra high vacuum with gold electrode surfaces acting as substrate surface for helium diffraction measurements. By simultaneous measurement of helium specular reflection intensity from the electrode surface and resonance frequency shift of the crystal during film adsorption, helium diffraction data can be correlated to film thickness. In addition, effects of interfacial viscosity on the helium diffraction pattern could be observed. To this end, first, flat gold films on AT cut quartz crystals were prepared which yield high enough helium specular reflection intensity. Then the crystals were mounted in the helium diffractometer sample holder and driven by means of a frequency modulation driving setup. Different crystal geometries were tested to obtain the best quality factor and preliminary measurements were performed on Kr films on gold surfaces. While the crystal structure and coverage of krypton films as a function of substrate temperature could successfully be determined, no depinning effects could be observed.
我们描述了一种石英晶体微天平装置，它可以在超高真空的低温环境下运行，其中金电极表面用作氦衍射测量的基底表面。通过在薄膜吸附过程中同时测量来自电极表面的氦镜面反射强度和晶体的共振频率偏移，可以将氦衍射数据与薄膜厚度相关联。此外，还可以观察到界面粘度对氦衍射图案的影响。为此，首先，在AT切割石英晶体上制备了具有足够高氦镜面反射强度的平坦金膜。然后将晶体安装在氦衍射仪样品架中，并通过调频驱动装置进行驱动。测试了不同的晶体几何形状以获得最佳品质因数，并对金表面的氪膜进行了初步测量。虽然可以成功确定氪膜的晶体结构和覆盖度随基底温度的变化，但未观察到脱钉效应。
