Internal calibration deposition

Seah et al. [20,32] have addressed the calibration of the intensity/energy response function for valid analytical measurements with electron spectrometers used in XPS and AES. Both techniques have matured to a sufficient level that calibration systems are now available which allow spectral intensities to be related from instrument to instrument. The KE axis is usually calibrated with reference to a signal belonging to an internal calibrant, e.g. the Cl - level of adventitious carbon due to pump oil or the Au4/7/2 level of gold vacuum-deposited on the sample. 

For scientific work the fundamental standard of mass is the international prototype kilogram, which is a mass of platinum-iridium alloy made in 1887 and deposited in the International Bureau of Weights and Measures near Paris. Authentic copies of the standard are kept by the appropriate responsible authorities in the various countries of the world these copies are employed for the comparison of secondary standards, which are used in the calibration of weights for scientific work. The unit of mass that is almost universally employed in laboratory work, however, is the gram, which may be defined as the one-thousandth part of the mass of the international prototype kilogram. 

Depending on purposes, a plastic film under the vapor-deposited C is dissolved away with a solvent. By this method, a very thin C support-film of smaller than lOnm in thickness can be made easily. An aluminum (Al) support-film can be made similarly, by vapor-deposition of Al onto a plastic film put on a grid and then by dissolving away the plastic film. The reflection rings from the Al support-film can be used as an internal reference to calibrate the camera length of SAED pattern, and this support film does give no amorphous halo. When an ultra-thin C support-film (less than 5nm in thickness) is desired, a microgrid (MG see Section 3.1.2) should be used on which an ultra-thin film made by indirect vapor-deposition of C has been put in advance. 

Eumstead ( ) chose native fluorite as an internal standard for the analysis of quartz in coal dust His procedure consisted of mixing 0 20 mg fluorite into each water suspension of standard and sample and depositing on silver membrane filters for a calibration curve (fluorite/quartz intensity ratio i[ . mg quartz) The application of this method to coal dust samples containing less than 1% quartz produced acceptable results relative standard deviation (RSD) was 18 2 ... 

A pair of elevated anchors with hydrophilic top surface allowed for sample and standard deposition in very close proximity (on the anchors), and thus improved mass calibration with an external standard. The approach actually mimicked an internal standard mass calibration procedure and enabled the analysis of 30 pL sample solutions corresponding to 1.5 amol of angiotensin peptides. 

Any structure may be constmcted for binary nanoclusters of platinum with transition metals of fourth or fifth row, while in accordance with material science solid solutions of substitution are easy formed. Our previous calculations [24 showed, that nanocluster forms, which are close to cubo-octahedral with 13 and 55 atoms, are the least nanoclusters with maximal internal energy, are the most stable ones and familiar to relatively quick theoretical study by 7)7 7 methods on PC. Besides, such nanoclusters are able to exist in experiments, for instance during LASER evaporating of platimun and deposition of particles with mass spectrometric calibration... 

---