Elemental spectroscopic imaging

The proposal that the nitrogen effect involved formation of nitrides which prevented the alumina from becoming continuous has been verified by elemental spectroscopic imaging (ESI) in a transmission electron microscope [70]. An ESI map for the elements II, Al, O, and N from a cross-section of the scale/alloy interface of Ti-50 at% Al oxidized in air for one hour at 900°C is presented in Figure 19. These maps indicate that the alumina is broken up by islands of TiN. 

X-ray powder investigations after thermal treatment up to 1650 C reveal the amorphous state of the ceramic material. Additionally, HRTEM investigations reveal the completely amorphous state at atomic scale of the samples heated up to 1650 °C. Furthermore, elemental maps of Si, B, N, and C recorded by electron spectroscopic imaging confirm a homogeneous distribution of the elements [5]. The Si-NMR spectra of the ceramic materials show one signal at -43 ppm (h>v4 = 1400 Hz) for a typical four-fold coordination of the silicon. 

In the application discussed below, the derivation of quantitative results from NIR spectroscopic imaging data of solid drug formulations is reported. In order to assess the vaUdity of these procedures, however, the results will be compared to the compositional analysis of the same sample set by conservative NIR spectroscopic diffuse-reflection measurements with a single-element detector [68]. 

FT-IR and Raman spectroscopic imaging techniques may employ three general approaches to obtain spatially resolved chemical information mapping, imaging with a multi-element detector, and spatial encoding and decoding. 

SIMS offers the possibility to acquire spectroscopic images where a spectral signature obtained from the detection of secondary ions is associated with each spatial resolution element (i.e.,pixel). In general, a spectral imager provides data in the form of a three-dimensional (3D) cube with two spatial dimensions and a third spectral dimension. The third dimension is often shown as gray scale or as false color representations. 

A deeper insight into the nanomorphology of the composite particles was provided by electron spectroscopic imaging (ESI) [190b]. The technique allows the es-tabhshment of elemental map compositions, and involves the use of conventional TEM and spectrometry. The method can be described briefly as follows. When an electron beam passes through the sample, interaction with electrons of different el-... 

For infrared microspectroscopy, single-element detectors are used for point and mapping measurements. More recently, array detectors have been applied for spectroscopic imaging in the infrared. In infrared focal plane arrays, the monolithic silicon design used in CCDs is replaced by a hybrid construction. In a hybrid detector, photon detection occurs in a semiconductor layer (indium antimonide, mercury cadmium telluride, and doped-silicon are typical detector materials), while the readout and amplification stages are carried out in a silicon layer. The two layers are electrically connected at each pixel through indium bump-bonds . Other innovations such as microbolometer arrays also show promise for spectroscopic imaging applications. 

Godleski JJ, Stearns RC, Katler M, Hastings CL. Detection of elements by electron spectroscopic imaging and analysis of electron energy loss spectra in alveolar macrophages prepared by slam-freeze molecular distillation processing. EMSA Proc 1990 48 776-777. 

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