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This paper addresses a current debate about the morphology of M7C3 phase in the chrome carbide overlay (CCO) and white iron community. This morphology was investigated using a serial sectioning technique in combination with computer post-processing software. A 600×600×300 μm volume of CCO was reconstructed in three dimensions (3D) to determine the difference between blade and rod-like carbide morphologies. The 3D analysis revealed that the two carbides morphologies correspond to the same hexagonal rod-like structures, but are oriented in different directions relative to the sectioning plane.

In this work, the microstructure of an Al 3 Nb–Nb 2 Al–AlNbNi ternary eutectic obtained by directional solidification was analyzed. Because the phase arrangement of this eutectic is highly complex, this study involved a three-dimensional reconstruction of the microstructure using the serial sectioning technique. The visualization of the reconstructed microstructure revealed that the fibers possessed a high degree of sinuosity. Although these fibers were continuous in the growth direction, they displayed a tendency to move back and forth across a central axis.

Reconstruction and visualization of three-dimensional (3-D) pores are of interest for understanding microstructure–properties relationships in cast Mg-alloys. In this contribution, a montage serial sectioning technique is applied to reconstruct a large volume of the 3-D microstructure of a new high-pressure die-cast AE44 Mg-alloy at a high resolution. The 3-D reconstruction reveals that the shapes and morphologies of the gas pores in the AE44 alloy are substantially different from those in other important cast Mg-alloys, which may partly account for the AE44 alloy’s superior properties.

The contour method, a newly-invented sectioning technique for residual stress measurement, has the potential to measure the cross-sectional residual stress profile of a weld in a simple and time-efficient manner. In this paper we demonstrate the capability of the contour method to measure cross-sectional residual stress profiles, which are compared with neutron diffraction measurements and show excellent agreement. The results provide useful information for safetycritical design of welded components and optimization of welding parameters, and also illustrate the potential of the contour technique as a powerful tool for residual stress evaluation.

The concept of asperity sharpness has recently been developed into a technique for the description of abrasive particle shape. This paper reveals further discoveries on the nature of particle shape and applies sharpness concepts to nominally planar abrasive surfaces composed of self-arranged particle stacks. The main purpose of the investigation is to determine whether there are any significant changes of surface shape that are dictated by particle size; thus establishing to what extent particle stacking influences the well known particle size effect. In pursuing this objective it has been found that the average shape of particle asperities can be conveniently modelled by a power-law—this useful discovery simplifies the description of abrasive particle shape. In addition, when particles are affixed to a planar substrate, the resulting surface exhibits unique properties that are convenient for surface characterisation and the development of abrasion models. The behaviour of these surfaces is investigated in relation to the underlying particle properties. The serial sectioning technique used to investigate the abrasive surfaces is described in this paper and preliminary results are also presented.

Ultrathin sectioning, one of the types of specimen preparations for transmission electron microscopy (TEM), has been considered the most perfect sectioning technique leading to the thinnest sections (50–100 nm). Following a study based on a newly developed low-voltage TEM technique, a relief on the ultrathin sections of polymer blends was observed that was ascribed to substantial differences in mechanical properties of the blend constituents.[1] In this study, an analogous relief was observed with a blend, the constituents of which are both hard in cutting. The origin of the surface relief on ultrathin sections of polymer blends was sought using low-voltage scanning TEM and atomic force microscopy. Polycarbonate/styrene-co-acrylonitrile blend was examined as a representative of blends with all components well under T g at room temperature. A distinct surface relief was observed on both ultrathin sections and remaining cut surfaces of the blend for low-temperature and room-temperature cutting. A rougher su...

Grain-boundary impurity diffusion of Au along the incoherent twin boundary in a diffusion-bonded Cu bicrystal has been studied by the serial sectioning technique. The measured penetration profiles had a rather atypical shape which we interpreted in terms of structural multiplicity of the grain-boundary structure. A method of processing such profiles has been suggested and the relative fraction of the grain-boundary structural modification exhibiting the lowest diffusion coefficient has been estimated as 60% . The difference between the energies of the two structural modifications has been estimated as being less than 17%, which is in good agreement with the results of computer simulations of the grain-boundary energy in Cu.

Grain boundary and interphase boundary diffusion has been investigated in the system Ag/Ni using the radiotracer serial sectioning technique. Ni segregation in Ag grain boundaries is strongly temperature dependent leading to the conclusion that Ni atoms are located mainly in the bulk planes adjacent to the grain boundary. From interphase boundary diffusion measurements in (110) oriented Ag/Ni interphase boundaries it can be deduced that the structure of this interphase boundary is incoherent.

The diffusion of Fe and Ge in the D03 phase Fe3Si has been studied as a function of temperature and composition using a tracer sectioning technique and the radioisotopes 59Fe and 71Ge. One experiment with the short-lived 31Si radiotracer was carried out to examine the similarity of Ge diffusion and Si diffusion. These elements diffuse with similar rates. The results are discussed considering composition dependences, magnetic and ordering transitions. The most striking fact is that Fe diffusion in the D03 structure Fe3Si is much faster and the corresponding activation enthalpy is considerably lower than in bcc Fe or in disordered Fe-rich Fe-Si alloys. By contrast, diffusion of Ge and Si is a great deal slower and the activation enthalpy is higher than in the disordered phases. While Fe diffusion is strongly dependent on the alloy composition, diffusion of Ge in Fe3Si is less affected by the Si content. Possible diffusion mechanisms are discussed in the light of additional information on Fe3Si. The...

The feature size dependence of plasma etch rates has been the focus of recent theoretical and experimental study [1–3]. The effect, already problematic at submicron dimensions, can limit attainable structures and is expected to increase in importance as lateral dimensions are further reduced. In this paper, the models previously reported are developed further and a new nanostructure trench sectioning technique is used to extend etch rate measurements to features with lateral dimensions below 100 nm. The experimental results are compared to the new models.

Measurements of Co diffusion in α-Ti were made by using radiotracers and the direct sectioning technique. The Arrhenius plot obtained is a straight line for the whole range of temperature covered (619–823 K) with Q = 127 ± 6 kJ mol−1 and D o = (3 ± 1)× 10−6m2s−1. The results show an excellent agreement with previous ones in the range (871–1135 K) and they suggest that there is no ultrafast impurity influence in the diffusion in the α-Ti matrix.

Results on the diffusion of Cl into CdTe are described. Diffusion anneals were carried out at selected temperatures in the range between 200 degrees C and 700 degrees C in evacuated SiO2 ampoules using a diffusion source of CdCl2 under saturated vapour pressure conditions. The concentration profiles were measured using a radiotracer sectioning technique. The profiles were found to be composed of four parts, to which a computer package consisting of the sum of four complementary error functions (erfc) gave satisfactory fits to the data. The fastest-diffusing component gave values of the diffusivity that agreed with previously published results. Proposals explaining how this type of diffusion may occur are given.

The application of the serial sectioning technique for the reconstruction of spatial microstructures is demonstrated using two single phase polycrystalline microstructures as examples. The materials examined are an austenitic steel and a ZnO ceramic. The practical procedure is described as well as the analysis of the planar sections. The spatial grain size distribution and number of grains per unit volume are determined using parameters obtained from planar sections. Significant differences are found between the determined spatial grain size distribution, given in histogram form, and values obtained using stereological models

Die Diffusionsparameter von Stickstoff (0 bis etwa 0.3 Ma%) in hochlegierten austenitischen Stahlen (12 bis 19 Ma%Cr, 12 bis 16 Ma%Ni, 0 bis 2 Ma%Mo) wurden im Temperaturbereich von 1283 bis 1573K ermittelt. Die geringen Konzentrationsgradienten von N konnten mittels folgender Methoden erfolgreich untersucht werden: (1) Kombination von mechanischer Schichtenteilung und chemischer N-Analyse bzw. Rontgenstrahl-Gitterparametermessung (2) Elektronenstrahl-Mikroanalyse (ESMA) oder KOSSEL-Ruckstrahltechnik am metallografischen Querschliff. Die N-Diffusionskoeffizienten (DK) wurden als konzentrationsunabhangig gefunden. Die Legierungselemente Cr und Mo senken das Diffusionsvermogen des N in hochlegierten austenitischen Stahlen, welches andererseits durch Ni erhoht wird. Eine Erklarung dafur kann im Zusammenhang mit einer Analyse der Wechselwirkungsparameter gegeben werden. Interdiffusion of nitrogen in high-alloy austenitic CrNi(Mo) steels Parameters of the diffusion of N (0 to 0.3 wt.%) in austenitic stainless steels (12 to 19 wt.%Cr, 12 to 16 wt.%Ni, 0 to 2 wt.%Mo) were determined within the temperature range of 1283–1573K. The small concentration gradients of N were successfully investigated using (1) mechanical serial sectioning technique in combination with either chemical N analysis or x-ray precision lattice parameter determination, (2) measurements on microsections by means of either Electron Probe Microanalysis or KOSSEL technique. The diffusion coefficients of N were found to be independent of its concentration. The alloying elements Cr and Mo reduce the N diffusivity in austenitic stainless steels which on the other hand is increased by Ni. An explanation of these results can be given in connection with the analysis of interaction parameters.

The diffusion of 59Fe in Incoloy 800 has been studied using the serial sectioning technique in the temperature ranges 1020–1500 K for volume diffusion and 750–1100 K for grain boundary diffusion, respectively. The volume diffusion coefficients can be represented by the expression: D(1020–1500 K)=3·26×10−5 exp (−259·6 kJ mol−1/RT) m2 s−l. The grain boundary diffusion coefficients were evaluated in most of the experiments using Whipple's method. For afew specimens, Suzuoka's method was applied. The penetration depths beyond which these methods were to be applied to analyse the experimental results were determined both graphically and by extensive use of autoradiographic techniques. The grain boundary diffusivities can be expressed as: Dgb (750–1100 K)=1·88×10−5 exp (−160·7 kJ mol−1/RT) m2 s−1, The results are discussed and presented in this paper.MST/l193

Grain-boundary heterodiffusion of iron in pure copper and self diffusion of iron in copper–0.091at% iron were measured by the serial sectioning technique in the Harrison B-regime. The penetration profiles corresponding to iron heterodiffusion in pure copper show a strong positive curvature far beyond the (Dvt)1/2 depth . This peculiar shape, which does not exist for self diffusion in the solid solution, proves the presence of a strong non linear grain-boundary segregation of iron in copper in spite of the respective surface energies of these metals. This segregation is linked to the size effect which is, as predicted by numerical simulation, the main driving force for grainboundary segregation.

The electron spin resonance (ESR) technique was used to investigate the diffusion of Cr 3+ in magnesium oxide (MgO) powders. The ESR absorption intensity was measured for several annealing times and four different temperatures of isothermal annealing: 1223, 1273, 1323 and 1373 K. The activation temperature for diffusion, calculated from the experimental data using a theoretical model based on the Fick equation, was found to be E A =212±9 kJ mol −1 . This result is about 30% smaller than similar data obtained for single-crystal MgO using the radioactive-tracer sectioning technique. The difference is attributed to a higher concentration of defects in the powder relative to single crystals.

The electron spin resonance (ESR) technique was used to investigate the diffusion of Fe 3+ in rutile (TiO 2 ). ESR absorption intensity was measured for several annealing times and three different temperatures of isothermal annealing: 1273, 1323 and 1373 K. The activation energy for diffusion, calculated from the experimental data using a theoretical model based on the Fick equation, was found to be E A = 215 kJ mol −1 . This result is consistent with experimental data using the radioactive-tracer sectioning technique and represents an independent measurement of the activation energy for diffusion of trivalent iron in rutile, which is difficult to achieve by other means in this mixed-valence system.

The diffusion of Ni-63 and Sb-124 is measured on single crystals of Ni53Sb47 by the sectioning technique. Diffusion coefficients for transport parallel and perpendicular to the crystallographic c-axis (D‖ and D⟂) and activation energies are reported. The dependence of D on composition is studied on polycrystalline samples of Ni53Sb47 and Ni50Sb50. For Ni a mechanism in which Ni atoms migrate between double tetrahedral interstices and vacancies of the Ni sublattice is proposed. The effect of composition on DNi is explained by structural vacancies of the Ni lattice. D⟂/D‖ ratios point to a vacancy mechanism for diffusion of Sb. An Einkristallen von Ni53Sb47 wird mit Hilfe der Abschleifmethode die Diffusion von Ni-63 und Sb-124 untersucht. Diffusionskoeffizienten fur die Richtung parallel und senkrecht zur kristallographischen c-Achse (D‖ and D⟂) werden angegeben. Die Konzentrationsabhangigkeit von D wird an polykristallinen Proben der Zusammensetzungen Ni53Sb47 und Ni50Sb50 untersucht. Fur Ni wird ein Diffusionsmechanismus vorgeschlagen, bei dem das Ni Atom zwischen Doppeltetraederlucken und Leerstellen des Ni Teilgitters hin und her springt. Der beobachtete Konzentrationseinflus wird bei DNi mit Hilfe struktureller Fehlstellen des Ni Teilgitters erklart. Das D⟂/D‖ Verhaltnis weist auf einen Leerstellenmechanismus bei der Diffusion des Sb Atoms hin.

Results of measurements between 533 and 1093 °C of the diffusion coefficient of Fe59 in two single crystals of FeSi (7.64 and 11.1 at% Si, respectively) are presented. For the lower temperatures a newly developed chemical sectioning technique was employed. The results show a marked ferromagnetic effect, i.e. the activation energy is strongly peaked at the Curie temperature. The results are analysed in terms of the Zener-LeClaire theory in combination with an argument that relates the enthalpy of vacancy formation with the change in magnetic specific heat of the matrix upon introduction of a vacancy. The latter argument can also be used exclusively when related to the introduction of an activated complex in the matrix. Es werden die Ergebnisse von Messungen des Diffusionskoeffizienten von Fe59 in zwei Einkristallen von Fe–Si mit 7,64 bzw. 11,1 At% Si im Temperaturbereich zwischen 533 und 1093 °C mitgeteilt. Die Messungen erfolgten oberhalb 700 °C nach der Schichtenteilungsmethode und unterhalb nach einer neu entwickelten chemischen Methode. Die Ergebnisse zeigen einen starken Einflus des Ferromagnetismus, d. h. die Aktivierungsenergie verandert sich im Bereich der Curie-Temperatur stark. Die Ergebnisse werden anhand der Zener-LeClaire-Theorie analysiert. Hinzugenommen wird der Einflus, den die Anderung des magnetischen Anteils der spezifischen Warme bei Bildung einer Leerstelle auf deren Bildungsenthalpie hat. Auserdem wird die Anderung der Curie-Temperatur durch das Auftreten von aktivierten Komplexen in der Matrix abgeschatzt.

The diffusion of 45Ca has been measured in single crystals of CaF2 and CaF2 + 0.34 mol % YF3 using a precision sectioning technique. In pure CaF2 between 800 and 1300 °C, D = = 4.8×107 exp (—5.160 eV/kT) cm2/s. The effect of YF3 is to increase D at temperatures below 950 °C but the magnitude of the increase is much smaller than expected for a vacancy mechanism unless a binding energy between Y3+ ions and cation vacancies of >0.6 eV is assumed. It is shown that the results may correspond to diffusion via cation–anion vacancy pairs at all temperatures investigated. Die Diffusion von 45Ca wird in CaF2- und CaF2 + 0,34 Mol%-YF3-Einkristallen unter Benutzung einer Abschleifmethode gemessen. In reinem CaF2 erholt man zwischen 800 und 1300 °C D = 4,8×107 exp (—5,160 eV/kT) cm2/s. YF3-Dosierung erhoht D bei Temperaturen unterhalb 950°C, jedoch ist die Grosenordnung der Erhohung fur den Leerstellenmechanismus viel geringer als erwartet, es sei denn, es wird eine Aktivierungsenergie zwischen Y3+-Ionen und Kationenleerstellen von >0,6 eV angenommen. Es wird gezeigt, das die Ergebnisse fur die untersuchten Temperaturen einer Diffusion uber Kationen–Anionen-Leerstellenpaare entsprechen.

Using the tracer-standard sectioning technique the impurity diffusion of indium in copper has been investigated in the temperature range from 798.1 to 1081.0°C. For the frequency factor and the activation energy, respectively, the following values were determined: D02 = 1.87 cm2 · s−1; Q2 = 2.034 eV. The results are compared with predictions of theoretical models of the impurity diffusion in metals. Mit Hilfe der Tracer-Standardschichtenteilungstechnik wurde die Fremddiffusion von Indium in Kupfer im Temperaturbereich von 798,1 bis 1081,0°C untersucht. Fur den Frequenzfaktor bzw. die Aktivierungsenergie wurden folgende Werte ermittelt: D02 = 1,87 cm2 · s−1; Q2 = 2,034 eV. Bei einem Vergleich der Ergebnisse mit theoretischen Modellen fur die Fremddiffusion in Metallen zeigt sich eine gute Ubereinstimmung zwi-Theorie und Experiment.

A study has been made of the diffusion of zinc, from a vapour source, into GaAs slices which had been previously implanted with various ion species. A radiotracer sectioning technique was used to measure the zinc diffusion profiles. It was found that the various implanted ion species (H+, He+, N+, Zn+, As+) had different effects on the zinc diffusion. The results could not be attributed solely to native defects produced by radiation damage. The heavier ion species increased the zinc concentration in the implanted region, but not beyond. The lighter species substantially increased the zinc diffusion rate and altered the resultant concentration profiles. Uphill diffusion was seen in slices which had been given a single high energy H+ implant. The results obtained are compared to those of Radiation-Enhanced-Diffusion experiments. It is suggested that the rate of incorporation of dopant species into the host semiconductor lattice is an important influence on the diffusion mechanism and the shape of the concentration profile.

Tracerdiffusion coefficients of Ni2+ and Ga3+ have been measured in Ni 1− y Ga 2+2 y 3 O 4 spinel solid solutions at 1585°C in air using a standard sectioning technique. The results are in good agreement with theoretical considerations assuming a vacancy mechanism for diffusion in the cation deficit region (y > 0) while both the vacancy and the interstitial mechanisms are operating within the range of cation excess (y

The diffusion of Fe2+ ion in AgCl has been found to proceed substitutionally over the temperature range of measurement (232 to 449 °C). The standard serial sectioning technique was used. The temperature dependence of the diffusion can be represented by D = 15.1 exp (−1.27/kT) cm2/s. If the activation enthalpy of migration for Fe2+ is taken as 0.6 eV, the association enthalpy is about 0.07 eV for Fe2+ vacancy complexes. On a trouve que la diffusion de l'ion ferreux dans le chlorure d'argent procede par substitution dans toute l'entendue de la mesure de temperature (232 a 449 °C). On a employe la technique courante du sectionnement en serie. On peut representer la dependence de temperature de la diffusion par D = 15,1 exp (−1,27/kT) cm2/s. Si on choisit 0,6 eV pour l'enthalpie d'activation de la migration pour Fe2+, l'enthalpie d'association est aux environs de 0,07 eV pour les complexes de vacance de l'ion ferreux.

The diffusion of Ce ions in AgCl has been measured by the tracer and serial sectioning technique. The temperature dependence of the diffusivity follows a linear Arrhenius law with parameters D 0 =1.10×10 −3 cm 2 /s and H =0.62 eV. It appears that Ce enters the lattice as +3 ion in substitutional sites and diffuses as an associated complex with cation vacancies. The results of the study of eiectrical conductivity of the pure and Ce-doped AgCl supports this general view. Alternate possibilities are also discussed.

The diffusion of antimony in fine-grained and coarse-grained polycrystalline silicon is studied in the temperature range from 930 to 1150 °C. The radioisotope 125Sb is used to measure concentration-depth profiles with the sectioning technique. Autoradiography is used for making the lateral distribution of the radioactivity over the sample surface visible and for quantitative analysis of the activity-depth profile of distinct grains in the coarse-grained samples. An important role is played by dislocation formation during the diffusion anneal. Die Diffusion des Antimons im feinkornigen und grobkornigen polykristallinen Silizium wird im Temperaturbereich von 930 bis 1150 °C untersucht. Das Radioisotop 125Sb wird in der “sectioning”-Technik fur die Bestimmung der Tiefenprofile der Aktivitat verwendet. Autoradiographie wird benutzt zur Sichtbarmachung der Verteilung von Radioaktivitat uber die Oberflache und fur die quantitative Analyse des Tiefenprofils von bestimmten Kornen in grobkornigen Proben. Die Entstehung von Versetzungen wahrend der Diffusionsheizung spielt eine wichtige Rolle.

A study is made on the diffusion of Ga into bare and oxide-covered Si by using a closed capsule technique. The diffused wafers are analysed by an anodically sectioning technique. It is found that when the temperature of oxidation (Tox) is greater than that of diffusion (Tdiff), the effect of the oxide layers is to enhance the diffusion and in the opposite case when To, is less than Tdiff, the diffusion is retarded due to the oxide. However, when To, is equal to Tdiff, there is little or no effect due to the oxide. These results are explained in terms of the stress at the Si/SiO2, interface and the resulting strain gradient in bulk Si. Es wird die Diffusion von Ga in unbedecktes und oxidbedecktes Si in geschlossener Ampulle untersucht. Die diffundierten Scheiben werden mittels anodischer Sektionstechnik analysiert. Es wird gefunden, das bei hoheren Oxidationstemperaturen (Tox) ale die Diffusions temperature (Tdiff) die Oxidschicht die Diffusion erhoht und im entgegengesetzten Fall, wenn Tox kleiner als Tdiff ist, die Diffusion infolge des Oxids verzogert wird. Wenn jedoch Tox gleich Tdiff ist, gibt es keinen oder nur einen geringen Einflus durch das Oxid. Diese Ergebnisse werden mit Spannungen an der Si/SiO2-Grenzflache und des resultierenden Verzerrungsgradienten im Si-Volumen erklart.

The diffusion profiles of iron have been very accurately measured in polyacetylene films, during their doping process with FeCl 3 , by using a radioactive isotope and a sectioning technique. Both in-diffusion from a labelled solution and out-diffusion towards an inactive solution have been studied. Saturation by thes dopant occurs at the mole fraction of 0.055. The crucial importance of the flow of dopant between the fibers is demonstrated. The rate of the isotopic exchange reaction is surprisingly high for a solid state reaction. These new data provide a better understanding of the doping mechanism.

Self- and gold-impurity diffusion measurements over the temperature range 850 to 1265 K are made on platinum single crystals using 197Pt and 199Au as radioactive diffusants and ion-beam sputtering as a sectioning technique. Gaussian penetration profiles are observed for well-annealed crystals. The influence of plastic deformation on the penetration curve is investigated and found to be considerable. The diffusivities obtained from well-annealed crystals fit the Arrhenius relations DPt = 0.05 exp (−2.67 eV/kT) cm2 s−1 for Pt self-diffusion and DAu = 0.13 exp (−2.61 eV/kT) cm2 s−1 for diffusion of Au in Pt. In conjunction with the high-temperature data of Kidson and Ross the present self-diffusion data are analysed in terms of mono- and divacancy contributions. For the sum of the enthalpy of formation and motion of a single vacancy a best value of 2.69 eV is deduced. The present Au-data close a gap since bulk diffusion measurements of Au in Pt are not available in the literature. Diffusion in the PtAu-system is important in semiconductor technology because of the frequent use of PtAu metallizations. Messungen der Diffusion von 197Pt und 199Au in Platineinkristallen werden im Temperaturbereich von 850 bis 1265 K mit Hilfe der Ionenstrahlzerstaubung als Schichtabtragetechnik durchgefuhrt. An gut ausgegluhten Kristallen werden Gaussche Eindringprofile beobachtet. Der Einflus plastischer verformung auf die Eindringkurve wird untersucht und erweist sich als betrachtlich. Die Diffusionskoeffizienten der gut ausgegluhten Kristalle werden durch die Arrhenius-Beziehungen DPt = 0,05 exp (−2,67 eV/kT) cm2 s−1 bei der Selbstdiffusion von Pt und DAu = 0,13 exp (−2,61 eV/kT) cm2 s−1 bei der Diffusion von Au in Pt beschrieben. In Verbindung mit den Hochtemperaturdaten von Kidson und Ross werden die Selbstdiffusionsdaten im Hinblick auf Einfach- und Doppelleerstellenanteile analysiert. Dabei ergibt sich fur die Summe aus Bildungs- und Wanderungsenthalpie der Einfachleerstelle ein bester Wert von 2,69 eV. Die Golddaten dieser Arbeit schliesen eine Lucke, da Messungen der Volumendiffusion von Au in Pt in der Literatur nicht vorhanden sind. Die Diffusion im PtAu-System ist in der Halbleitertechnologie von Bedeutung wegen der haufigen Verwendung von PtAu-Metallisierungen.

Diffusion and Solubility of Cr51 in Silver Single Crystals investigated in the temperature range 976 to 1231 K using the serial sectioning technique. Solubility Xcr and diffusion coefficient D can be described by the following temperature functions: Xcr = exp [−1.76 ± ± 0.02) eV/kBT] and D = exp [−(2.00 ± 0.02) eV/kBqT] cm2 8−1. At the melting point the solubility of chromium is as small as 100 ppm. The results of the chromium diffusion cannot be explained in terms of the current models of impurity diffusion. Im Temperaturbereich zwischen 976 und 1231 K werden die Diffusion und die Loslichkeit von Cr51 in Silbereinkristallen mit Hilfe der Sektionsmethode untersucht. Loslichkeit Xcr und Diffusionskoeffizient D konnen durch die folgenden Temperaturfunktionen beschrieben werden: Xcr = exp [−(1,76 ± 02) 0v/kBT] und D = exp [−(2,00 ± ± 0,02) ev/kBT] cm2 s−1. Am Schmelzpunkt betrugt die Loslichkeit von Chrom lediglich 100 ppm. Die Ergebnisse der Chromdiffusion in Silber stehen nicht im Einklang mit den bekannten Fremddiffusionsmodellen.

The diffusion of donor elements in fine-grained and coarse-grained polycrystalline silicon is studied in the temperature range from 900 to 1150°C. The radioisotopes 125Sb, 32P, and 74(73)As are used to measure concentration-depth profiles by the sectioning technique. By autoradiography the lateral distribution of the radiotracers over the sample surface is made visible. An extensive comparison with literature data is given. Die Diffusion der Donatorelemente in feinkornigem und grobkornigem polykristallinem Silizium wird im Temperaturbereich von 900 bis 1150°C untersucht. Die Radioisotope 125Sb, 32P und 74(73)As werden in der ‘sectioning’-Technik fur die Bestimmung der Tiefenprofile der Aktivitat verwendet und auch fur Autoradiographie, womit die Verteilung der Radioaktivitat uber die Oberflache sichtbar gemacht werden kann. Die Daten werden ausfuhrlich mit Literaturergebnissen verglichen.

Der Reihenentwicklungskoeffizient zweiten Grades ist ein brauchbares Mas fur die Einschatzung des Fehlers experimentell bestimmter Polfiguren kubischer Materialien. Die Fehlerkoeffizienten hoheren Grades ermoglichen auserdem die Trennung der systematischen von den statistischen Fehlern. Es wurden vierzig in der Literatur angegebene Polfiguren untersucht. Die aus rontgenographischen Durch- und Ruckstrahlmessungen kombinierten Polfiguren weisen im allgemeinen wesentlich hohere Fehler auf als Messungen an Kugel- oder Zylinderproben, Proben mit Schraganschliff sowie Neutronenbeugungsmessungen. The second order coefficient of an expansion into a series is a usefull measure of the error of an experimentally determined pole figure. The higher order error coefficients may be used to distinguish between systematic and statistic errors. Fourty pole figures, published in the literature, have been analysed. Pole figures measured by a combined transmission and reflection technique exhibited the highest level of error. Those measured with zylindrical or spherical specimen, by the oblique sectioning technique or by neutron diffraction are much better.

Sulphur diffusion in copper single crystals was studied at temperatures lower than 800°C for very short diffusion times. The distances of penetration were about 5 μm and a submicron sectioning technique was used. The curves obtained under these conditions do not follow a law of volume diffusion. These facts were interpreted by ascribing the role of diffusion short circuits to dislocations.

Experimental details are given of a thin film sectioning technique for the measurement of tracer diffusion in lithium metal. Results are given for 65Zn in Li between 57 and 173 °C. They are expressed by D = D0exp ( − Q/RT), where and Q = = (12.98 ± 0.24)kcal/mol. The activation energy equals, within margins of error, that of self-diffusion in Li. The agreement between vacancy based theories and the present results appears rather doubtful. Experimentelle Einzelheiten einer Dunnschicht-Schnittechnik fur Diffusionsmessungen an Lithiummetall werden beschrieben. Es werden Ergebnisse fur 65Zn in Li zwischen 57 und 173 °C angegeben, die sich durch D = D0exp ( − Q/RT) ausdrucken lassen, mit D0 = und Q = (12,98 ± 0,24) kcal/mol. Die Aktivierungsenergie ist, innerhalb der Fehlgrenzen, gleich derjenigen der Selbstdiffusion. Die Ubereinstimmung der auf Leerstellen gegrundeten Theorien mit diesen Ergebnissen erscheint ziemlich zweifelhaft.

An electrolytic sectioning technique has been used to measure self-diffusion coefficients in silver single crystals in the temperature range 300–800 °C. The results are analyzed in terms of diffusion through the crystal lattice, enhanced by diffusion along dislocations.

In the present studies of self diffusion in gallium the diffusion coefficients in single crystals and coarse-grained polycrystals were found to be extremely low. The results are only claimed to be of qualitative interest because of limitations set mainly by the short half-life of the radiotracer used. Even so two main conclusions can be drawn: (i) there is no clear evidence of marked anisotropy of self diffusion, and (ii) for gallium and other soft or friable metals a microtome sectioning technique is to be preferred to a grinding method.

Using a steady-state sectioning technique the migration of 22Na in Li has been investigated under temperature gradients and electric currents. The thermotransport “heat of transport” has been found to be Q* = (−3.0 ± 1.2) (kcal/mol), and the “effective charge number” of electrotransport z* − 4.7 ± 1.9. Theory predicts the electronic share of the heat of transport to be small, while the phonon contribution, only qualitatively treated, may be of the order of + 1 kcal/mol. The intrinsic contribution is calculated to be Q*0 = (−4.0 ± 2.5) kcal/mol. Classical models applied to Q*0 give indication that Na diffuses substitutionally in Li, and that the vacancy formation energy amounts to about two thirds of the diffusion activation energy. This is in line with evidence from X-ray dilatometry. The electrotransport results yield the effective resistivity of the activated impurity–vacancy complex, about 1.6 μ μΩ cm/% defects. It is suggested that in Li self-transport a considerable role may be played by interstitials. Mittels einer Schnittechnik fur Stationarprofil wird die Wanderung von 22Na in Li bei thermischen Gradienten und bei elektrischem Stromdurchgang untersucht. Die „Uberfuhrungswarme” des Thermotransport wird zu Q* = (−3,0 ± 1,2) kcal/Mol bestimmt, die „effektive Ladungszahl” des Elektrotransports zu z* = −4,7 ± 1,9. Der Theorie nach ist der elektronische Teil der Uberfuhrungswarme gering. Der Beitrag der Phononen, bisher nur qualitativ behandelt, durfte von der Grosenordnung + 1 kcal/Mol sein. Der Beitrag der Diffusionsenergien wird zu Q*0 = (−4,0 ± 2,5) kcal/Mol berechnet. Aus klassischen Modellen fur Q*0 wird gefolgert, das Na in Li substitutionell diffundiert, und das die Leerstellen-Bildungsenergie etwa zwei Drittel der Diffusions-Aktivierungsenergie betragt. Dies wird durch experimentelle Ergebnisse der Rontgen-Dilatometrie bestatigt. Die Messungen des Elektrotransports ergeben einen effektiven spezifischen Widerstand fur den aktivierten Verunreinigungs–Leerstellen-Komplex von ungefahr 1,6 μ μΩcm/% Defekte. Es wird angedeutet, das im Selbsttransport von Li Zwischengitteratome eine wesentliche Rolle spielen konnten.

A sectioning technique is developed to circumvent problems associated with the conventional procedure. The new technique consists of wax mounting the sample in a suitable chuck followed by chemical-mechanical polishing using Nalcog slurry. Basic features of a chuck design and polishing characteristics, and some results of defect analysis of thin silicon sheets, afforded by this technique are briefly described. 1 ref.

Diffusion of 54 Mn in Mn 1−δ O single crystals has been measured by a serial sectioning technique as a function of temperature (1000–1500°C) and deviation from stoichiometry (0.00003 m in the expression D = D 0 (T)p O 2 1 m varies from about 6 at low P o 2 at all temperatures to a value approacing 2 at high P o 2 and high temperatures, thus suggesting that diffusion occurs by doubly charged vacancies at low P o 2 with increasing contributions from singly charged and neutral vacancies as P o 2 (and vacancy concentration) increases. For δ near 0.1, the values of D fall below the values extrapolated from smaller defect concentrations. The isotope effect for cation self-diffusion was measured by simultaneous diffusion of 52 Mn and 54 Mn in Mn 1−δ O (0.0004 f ΔK are independent of temperature within experimental error, and decrease from a value of 0.70 at low defect concentrations to 0.37 for large values of δ. The isotope-effect results suggest that diffusion occurs by single non-interacting vacancies at low defect concentrations; defect-defect interactions become important for δ ≳ 0.01. The defect-defect interactions may involve essentially individual defects or may result in defect clusters; the similarity between the present isotope-effect results and those for Fe 1−δ 0 suggests that defect clustering plays a significant role in mass transport in Mn 1−δ O at large values of δ.