Microscopy, charge collection

A powerful method for the characterization of the origin of losses on structured surfaces is provided by the EBIC (Electron Beam Induced Current) technique also known as charge collection microscopy (23. 24). 

Leach C, Freer R, Azough F, Ling Z. Direct observation of the barrier structure of a praseodymium-doped grain boundary in a zinc oxide bicrystal by charge collection microscopy. Interface Sci. 2000 8 141-146. DOI 10.1023/A 1008772421392. 

Particles become positively charged by a corona discharge and travel out of the charging chamber and collect on a substrate such as a microscope slide. Thus, the method is useful for particles which are to be examined by optical or electron microscopy. 

Electrostatic precipitators collect particles that may subsequently be examined by microscopy. The method precipitates particles according to the charge they carry. The aerosol is passed between two plates or surfaces across which is a large potential difference. Deposition occurs as a function of the ratio of the charge to the inertia (mass and velocity) of the particles [87]. The principle on which this method is based considers the motion of particles in planes directly perpendicular to and parallel to the plane of the condenser [88]. 

Deme, B., Dubois, M., Gulik-Krzywicki, T. and Zemb, Th. (2002) Giant collective fluctuations of charged membranes at the lamellar-to-vesicle unbinding transition. 1. Characterisation of a new lipid morphology by SANS, SAXS, and electron microscopy. Fangmuir, 18, 997-1004. 

SEM (scanning electron microscopy)—an electron beam is focused onto a small region of a sample contained within a vacuum. The beam is scanned across the sample and the backscattered electrons (those undergoing elastic collisions) and the secondary electrons (those electrons released through inelastic collisions) are collected on a positively charged detector to obtain an image on a scintillation screen or electronic detector. 

The role of bacteria. In a recent study on the activity of benthic bacteria in Amazonian rivers (22), microbial biofilms were collected off of submerged plants and sediment, and subsequently analyzed with transmission electron microscopy (TEM), coupled with energy dispersion X-ray spectroscopy (EDS) and selected area electron difiraction (SAED). th TEM, it was observed that bacterial biomineralization involved a complex interaction between metals in solution with the reactive components of the cell. The anionically-charged cell wall and the encompassing layers provided special microenvironments for the deposition of iron and other soluble cationic species. Ferric iron, which exhibits unstable aqueous chemistries, was bound in significant amoimts, and previous studies indicate that... 

In this chapter we describe advances in the femtosecond time-resolved multiphoton photoemission spectroscopy (TR-MPP) as a method for probing electronic structure and ultrafast interfacial charge transfer dynamics of adsorbate-covered solid surfaces. The focus is on surface science-based approaches that combine ultrafast optical pump probe excitation to induce nonlinear multi-photon photoemission (MPP) from clean or adsorbate covered single crystal surfaces. The photoemitted electrons transmit spectroscopic and dynamical information, which is captured by their energy analysis in real or reciprocal space. We examine how photoelectron spectroscopy and microscopy yield information on the unoccupied molecular structure, electron transfer and relaxation processes, light induced chemical and physical transformations and the evolution of coherent single particle and collective excitations at solid surfaces. 

---