Depth profiling technique

The depth profiling technique used on samples with a barrier film before and after the addition of chloride to the buffering borate electrolyte showed no indication of either chloride penetration or significant reduction of the average oxide layer thickness.123 This, of course, does not rule out the possibility of the formation, by any of the mechanisms suggested above, of pinholes with radii much smaller than that of the ion-gun beam, through which the entire active dissolution could take place, or the possibility that the beam missed pits formed sporadically across the surface. If pinholes which are not visible were formed, the dissolution should proceed in them with extremely high true current densities. 

Neutron depth profiling technique (NDP) [13]. NDP is a speeial method for depth profiling of few light elements, namely He, Li, B and N in any solid material. The method makes use of speeifie nuelear reaetions of these elements with thermal neutrons. The samples are plaeed in the neutron beam from nuclear reactor and the charged products of the neutron indueed reactions (protons or alpha particles) are registered using a standard multiehannel spectrometer. From the measured energy spectra the depth profiles of above mentioned elements can be deduced by a simple computational procedure. 

The sum of these observations suggests that metal phosphate crystalline mineral phases, some of which are solid solutions, are present in the samples. These phases may be discrete or surface precipitates. Some work on scmbber residues using depth profiling techniques with secondary ion mass spectrometry (SIMS) suggest that surface... 

Destructive methods involve mechanical and chemical erosion (low resolution) and ion sputtering, which is by far the most widely used of any of the depth profiling techniques. Surface atoms are progressively removed by ion bombardment and are analysed by SIMS. Alternatively, the residual surface may be analysed, generally by AES. The method is universally applicable and in principle is capable of near-atomic depth resolution. In practice, conversion of the observed signal, as a function of time, into concentration as a function of depth may not be easy for a complex system. It should be noted that the information obtained is reliable for the first layer, but for deeper layers the possibility of scrambling of the atomic layers... 

Depth profiling techniques applied to thermodynamically equilibrated thin films characterize the compositions of coexisting phases and the spatial extent of the separating interface. This procedure repeated at different temperatures yields the coexistence curve and the corresponding temperature variation of the interfacial width. Determined coexistence curves are well described by the mean field theory with composition-dependent bulk interaction parameter [74]. The same interaction parameter also seems to generate the interfacial widths in accordance with results presented here [107] (Sect. 2.2.2) and elsewhere [88, 96, 129]. These predictions may however need to be aided by capillary wave contributions to fit another observations [95, 97, 98], especially those tracing the change of the interfacial width with film thickness [121,130] (see Sect. 3.2.2). 

Here z(( )00) is the distance from the surface (at depth z=0) to the plateau in composition. The surface enriched/depleted in blend component A is characterized by positive/negative z (see Fig. 15). Relatively large correlation lengths for polymer mixtures (see Sects. 2.1 and 2.2.2) lead to the surface profiles ( )(z) of sufficient spatial extent that may be easily traced by current depth profiling techniques [29]. Surface enrichment has been observed at a free surface [164,165] and at a substrate [92] as well as at an interface between binary blend and a homopolymer [166]. 

All direct depth profiling techniques used to study the surface segregation from binary polymer mixtures have a depth resolution [29] p limited to some 5-40 nm HWHM (half width at half maximum of the related Gaussian function). They cannot observe the real composition profile < )(z) (for the sake of comparison mimicked by mean field prediction (dashed line) in Fig. 16a) but rather its convolution (solid line in Fig. 16a) with an instrumental resolution function characterized by p. The total surface excess z however provides a good parameter, independent of resolution, as it has been concluded based on experimental data obtained using different direct techniques [170]. 

Spatial features of the brush profile are observed with the precision determined by the resolution p of depth profiling techniques used. The resolution p, described as a half width at half maximum (HWHM) of a Gaussian function, should be at least comparable with the unperturbed dimension of the brush, characterized by its radius of gyration Rg(N). Therefore nuclear reaction analysis [19] (NRA, p=8 nm), secondary ion mass spectroscopy [26, 27] (SIMS, p=... 

The development of the neutron depth profiling technique has been motivated by the importance of boron in both optical and microelectronic materials. Boron is widely used as a p-type dopant in semiconductor device fabrication and in the insulating oxide barriers applied as an organometallic or in vapor phase deposition glasses. 

The commercial aluminum-polyethylene composite film was kept in a soxhlet extractor and xylene was used in a 14-hour extraction to remove the polyethylene from the composite film. After removal of the polyethylene film the remaining film was rinsed by ethyl alcohol and dried. The dried film was used in the study of aluminum-polyethylene "free interface by AES depth profile technique. 

Nagpure S. C., Downing R. G., Bhushan B., Babu S. S., Cao L. Neutron depth profiling technique for studying aging in Li-ion batteries, Electrochim. Acta 2011, 56, 4735-4743. 

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