SEM Sample Preparation

Calcinated samples were fractured and the cross-sections were imaged without any further preparation steps. As-deposited (non-calcinated) ALD films were fractured and then etched with oxygen plasma for 2 min at 100% power to free the cross-sections from the polymer template. 

---

Fig. 20 SEM (sample preparation critical point drying) of inner surface areas. 1 - BASYC in the middle region of the interposition four weeks after implantation in the carotid artery of the rat with endothelial cells, 2 - BASYC before incorporation. Reprinted with permission from [65]...

Figure 5.27 SEM images of a G. sulfurreducens biofilm grown on a QCM electrode at (a) 27x, (b) 800x, and (c) 6000x magnification, (d) Camera image of the biofilm before SEM sample preparation. G. sulfurreducens biofilms on QCM electrodes appeared to cover the electrode surface uniformly. Reproduced with permission from Ref. [59]. Copyright 2014 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim.

Soybean phosphatidylcholine (Phospholipon 80, Nattermann Phosphohpid, Germany), PRO from grape Vitis vinifera L.) seeds [18] and propylenghcol (Sigma, USA) were used for hposome preparation. Osmium tetraoxide and absolute ethanol (Merck, Germany) were used for scanning electron microscopy (SEM) sample preparation. All other chemicals were of analytical grade. 

For example, the sample surface for electronic microscope observation is prepared by mechanically breaking or cutting of raw sample, followed by further treatment of the fresh surface of the sample. During such a process, the sample surface must bear the mechanical shock at low temperature, the vacuum and coating at room temperature, and the electron beam. It is easy to understand that the particles of low molar mass material on the sample surface can be lost during the sample preparation. However, with polymer components, it is possible to detect their distribution using normal SEM sample preparation. 

Electron Beam Techniques. One of the most powerful tools in VLSI technology is the scanning electron microscope (sem) (see Microscopy). A sem is typically used in three modes secondary electron detection, back-scattered electron detection, and x-ray fluorescence (xrf). AH three techniques can be used for nondestmctive analysis of a VLSI wafer, where the sample does not have to be destroyed for sample preparation or by analysis, if the sem is equipped to accept large wafer-sized samples and the electron beam is used at low (ca 1 keV) energy to preserve the functional integrity of the circuitry. Samples that do not diffuse the charge produced by the electron beam, such as insulators, require special sample preparation. 

SPMs are simpler to operate than electron microscopes. Because the instruments can operate under ambient conditions, the set-up time can be a matter of minutes. Sample preparation is minimal. SFM does not require a conducting path, so samples can be mounted with double-stick tape. STM can use a sample holder with conducting clips, similar to that used for SEM. An image can be acquired in less than a minute in fact, movies of ten fiames per second have been demonstrated. ... 

First of all, only the samples, prepared according to the procedure (a) were suitable for scanning electron microscope (SEM) measurements. All other samples were very un-... 

The morphology of samples prepared using various surfactants w investigated. Figures 1 and 2 show FE-SEM photographs and X-ray diflfraction patterns of the obtained... 

This technique can be applied to samples prepared for study by scanning electron microscopy (SEM). When subject to impact by electrons, atoms emit characteristic X-ray line spectra, which are almost completely independent of the physical or chemical state of the specimen (Reed, 1973). To analyse samples, they are prepared as required for SEM, that is they are mounted on an appropriate holder, sputter coated to provide an electrically conductive surface, generally using gold, and then examined under high vacuum. The electron beam is focussed to impinge upon a selected spot on the surface of the specimen and the resulting X-ray spectrum is analysed. 

Sample Preparation. Samples for mechanical studies were made by compression molding the polymers at 150°C between Teflon sheets for 15 minutes followed by rapid quenching to room temperature in air. These will be referred to as PQ (press-quenched or simply quenched) samples. The thickness of the PQ samples was around 10 mils (0.25 mm). The thermal history of all of the PQ samples (HBIB, HIBI, and LDPE) were essentially the same. They were used within one week after they were pressed. Samples for morphology, SALS and SEM studies were prepared from toluene solutions. These films were cast on a Teflon sheet at 80 C from a 1% (by weight) solution in toluene. These films were about 5 mils in thickness. When the polymer films had solidified (after 5 hrs), they were stored in a vacuum oven at 80°C for two days to remove residual solvent. These samples will be designated by TOL (solution cast from toluene). 

Sample preparation for more specialized work can require more intensive procedures and accessories [49]. Stages have been made for the SEM to accommodate a variety of experiments [50]. Heating, cooling, and mechanical manipulation would be useful for most pharmaceutical materials, but other... 

The use of EM (except in the special case of SEM) demands that the catalyst, whether mono-or multi-phasic, be thin enough to be electron transparent. But, as we show below, this seemingly severe condition by no means restricts its applicability to the study of metals, alloys, oxides, sulfides, halides, carbons, and a wide variety of other materials. Most catalyst powder preparations and supported metallic catalysts, provided that representative thin regions are selected for characterization, are found to be electron transparent and thus amenable to study by EM without the need for further sample preparation. 

Figure 2.9. Schematic of a matrix-assisted laser desorption/ionization (MALDI) event. The SEM micrograph depicts sinapinic acid-equine myoglobin crystal from a sample prepared according to the dried drop sample preparation method. In the desorption event neutral matrix molecules (M), positive matrix ions (M+), negative matrix ions (M-), neutral analyte molecules (N), positive analyte ions (+), and negative analyte ions (-) are created and/or transferred to the gas phase. Reprinted from A. Westman-Brinkmalm and G. Brinkmalm (2002). In Mass Spectrometry and Hyphenated Techniques in Neuropeptide Research, J. Silberring and R. Ekman (eds.) New York John Wiley Sons, 47-105. With permission of John Wiley Sons, Inc.

LEED requires a coherence length of ordered domains on the order of at least 100 A to be useful (36). SEM images are typically limited to resolution of 50 A, but are useful due to their depth of field and wide field of view (37). High resolution TEM can yield images of solids to a resolution of 1-2 A, but requires extensive sample preparation and also requires that the surface atoms be in registry with the remainder of the bulk sample under study (14,38). Clearly, each technique provides valuable information which complements the others, and ideally a combination of the probes would be used to obtain a complete characterization of the surface under study. 

The morphology of mesoporous structures can be investigated by TEM, as shown in Fig. 7.2 b and d. However, sample preparation for TEM is time-consuming. Fortunately the mesoporous regime can also be studied by today s most advanced SEMs. For SEM inspection no sample preparation is required, and even sputtering of the sample is dispensable, as shown by the SEM micrographs displayed in this and the next section. 

---