The microscopic nature of the Mossbauer phase analysis has been found as being particularly valuable in testing assumptions suggested by TEM results regarding the microdomain structure and the population of different lattice sites by iron ions in the perovskite system (1 - y)La(2/3)rectangle(1/3)TiO(3).yLaFeO(3) with 0.04 < y < 0.25 (rectangle is an A-site vacancy). This system was found to contain only Fe3+-phases which are stable under normal conditions, but moderate heating in vacuo causes a partial reduction of ferric ions to ferrous ions.

The microscopic nature of the Mössbauer phase analysis has been found as being particularly valuable in testing assumptions suggested by TEM results regarding the microdomain structure and the population of different lattice sites by iron ions in the perovskite system (1-y)La2/3\(A\)1/3TiO3·yLaFeO3 with 0.04<y < 0.25 (\(A\) is an A-site vacancy). This system was found to contain only Fe3+-phases which are stable under normal conditions, but moderate heating in vacuo causes a partial reduction of ferric ions to ferrous ions.

The resonance Raman excitation profiles of the vibrational modes of the emeraldine salt form of polyaniline protonated with camphor sulfonic acid are remarkably and selectively enhanced, indicating improved structural and electronic order. We demonstrate that the electronic states near the Fermi energy (EF) of metallic polyaniline interact with a specific optical phonon mode. The 1598 cm−1 Raman-active vibrational mode (Ag symmetry) exhibits a distinct resonance enhancement associated with the mid-infrared (mid-IR) absorption in metallic PANI. Since the mid-IR oscillator strength results from the intraband free-carrier Drude absorption, the symmetry of the electronic wavefunctions near EF matches the vibrational pattern of the 1598 cm−1 normal mode. In contrast, the same mode shows no resonance enhancement with the interband absorption at 2.6 eV, implying that the symmetry of the bond relaxation of the excited state is orthogonal to the vibrational pattern of the 1598 cm−1 mode. By contrast, the resonance Raman excitation profile of the 1626 cm−1 mode is in strong resonance with the 2.6 eV absorption, but this mode is not as strongly in resonance with the free-carrier Drude absorption.

The microstructure of SrO-doped CaTiO3 ceramics was investigated using transmission electron microscopy (TEM). It was found that the excess SrO forms insertion planar precipitates which are coherently intergrown with the CaTiO3 crystal. Two different types of SrO intergrowth were observed: (101)/(001)SrO/(020) and (020)/(001)SrO/(020). The phenomenon is similar to that observed by Ruddlesden and Popper in the system SrTiO3-SrO.

Multilayer structures for application in microelectronics, hard and wear resistant as well as optical coatings are becoming increasingly complex. Therefore, there is a permanent need for new model multilayer structures appropriate for high resolution depth profiling studies which are helpful for the interpretation of everyday analytical results. A new type of metal/oxide multilayer structure composed of alternating Cr, Ni, NiO and Cr2O3 layers with a total thickness of about 475 nm was sputter deposited onto a smooth silicon substrate. By TEM investigations we found a columnar crystalline structure of Ni, Cr and NiO layers with a comparable size of crystal grains while the Cr2O3 layer showed a partial amorphous structure with a small amount of a crystalline phase. Compositional depth profiles of the model multilayer structure were obtained with Auger and X-ray photoelectron spectroscopy on stationary and rotated samples. The AES and XPS depth profiles are discussed with respect to different instrumental parameters and the influence of crystalline and amorphous structures on depth resolution. The AES depth profiling of stationary samples, using a unidirectional ion beam, shows an evident beneficial influence of the oxide sandwich layers on depth resolution.

There exists a permanent need for new model systems appropriate for the study of depth profiling with different surface analysis techniques, e.g. AES, XPS and SIMS, which involves the ion sputtering process. The development, preparation, transmission electron microscopy (TEM) characterization and AES depth profiling behaviour of the following new multilayer structures are presented: metal/oxide and oxide/oxide multilayers composed of Ni, Cr, NiO and Cr2O3 thin films and metal/semiconductor multilayers composed of Ni, Cr and Si thin films. These multilayer structures were, sputter deposited on smooth silicon substrates- and were precisely characterized with AES depth profiling during sample rotation and (two of them) with TEM. The measured compositional depth profiles are explained with respect to the influence of crystalline and amorphous structures on depth resolution, and the advantages of each type of multilayer structure are discussed.

On the basis of the topotaxy between BaTiO3 and Ba6Ti17O40 found recently, a model of a nonconservative (111) twin in TiO2‐rich BaTiO3 was constructed. The model consists of several (001) layers of Ba6Ti17O40 intergrown between (111) layers of BaTiO3, the core of the twin being a slightly modified double layer of Ba6Ti17O40 containing face‐sharing octahedra. Using this model, anomalous grain growth below the eutectic temperature and preferential growth of (111) twins in a reducing atmosphere were explained, as well a nucleation of butterfly twins.

Calcines of precipitated zirconia powders were studied by HREM and ED. Aggregates of originally amorphous particles form nonperfect crystallites which scatter single crystal ED reflection into subreflections. This scattering was attributed to the lattice strain.

The magnetic and mechanical properties of zirconia-added NiZn ferrite were studied. It was found that the addition of small amounts of ZrO2 improves their magnetic properties to a great extent. Magnetic losses at 10 MHz decreased by a factor of two with no significant change in permeability whereas the flexural strength of the material can be improved by the same factor of two while adding 0.5 wt.% of dopant. It is hypothesized that the microstructural changes and, consequently, the change in the electrical conductivity influence the magnetic losses. The interface changes allow the explanation of mechanical properties improvements.

Rapidly quenched alloys provide an opportunity to study the different phases of transformation that take place during solidification. Structural defects such as stacking faults and overlapping stacking faults, observed in different parts of disc samples, initiated this study, which sets out to explain the mechanism for the transformation from fcc to hcp in Co-TaC solid solution. The observed defects can be regarded as nuclei for the transition from one close-packed structure to the other. This paper describes phenomena related to the Co-10 wt.% TaC alloy, and draws comparisons between these and the martensitic transformations in pure Co, in other Co-based alloys, and in steels.

A TEM investigation was conducted on the structure of a second phase precipitated between the grains of a polycrystalline TiO2‐rich BaTiO3 which was doped with 8 mol% Ca. This phase was identified as Ca‐stabilized Ba2Ti5O12 with a 10‐layer orthorhombic structure and unit‐cell parameters a=0.990, b=1.131, and c=2.330 nm.

The orientational relationship between intergrown lamellae of tetragonal (t) BaTiO3 and monoclinic (m) Ba6Ti17O40 was found to be (111)t||(001)m, (001)t||(101)m, and [110]t||[010]m. On the basis of this relationship a model of a topotactic boundary between these two phases was constructed.

The oxidation of tin-oxide thin films is studied by electron microscopy and diffraction. Cassiterite, the rutile-like form of SnO2, is formed during oxidation of amorphous films deposited on the carbon precoated substrates, while a new form of SnO2 with the structure of brookite is obtained if the epitaxial films of α-SnO grown on sodium chloride substrates are oxidized. The growth of the new form is explained to be due to lesser misfit between the lattices of α-SnO and brookite as compared to that of cassiterite. Die Oxidation von dünnen Zinnoxidschichten wird mittels Elektronenmikroskopie und -beugung untersucht. Während der Oxydation von amorphen auf mit Kohlenstoff vorbeschichteten Substraten wird Cassiterit, die Rutilform von SnO2 gebildet, während eine neue Form von SnO2 mit der Struktur von Brookit erhalten wird, wenn epitaktische Schichten von α-SnO auf Natrium-chloridsubstrate oxydiert werden. Das Wachstum der neuen Form wird damit erklärt, daß ein geringeres Misfit zwischen den Gittern von α-SnO und Brookit im Vergleich zum Cassiterit be-steht.

Ba-doped NiZnCo ferrites were studied using transmission electron microscopy. Randomly distributed rectangular platelets of hexagonal ferrite W-phase were found to join the spinel grains along the (111)S∥ (0001)W faces forming a topotactic grain boundary.

Journal of the American Ceramic SocietyVolume 65, Issue 12 p. C‐203-C‐204 Release of Oxygen During the Sintering of Doped BaTiO3 Ceramics M. Drofenik, M. Drofenik J. Stefan Institute, E. Kardelj University, Ljubljana, YugoslaviaSearch for more papers by this authorA. Popović, A. Popović J. Stefan Institute, E. Kardelj University, Ljubljana, YugoslaviaSearch for more papers by this authorL. IrmanČnik, L. IrmanČnik J. Stefan Institute, E. Kardelj University, Ljubljana, YugoslaviaSearch for more papers by this authorD. Kolar, D. Kolar J. Stefan Institute, E. Kardelj University, Ljubljana, Yugoslavia Member, the American Ceramic Society.Search for more papers by this authorV. Kraševec, V. Kraševec J. Stefan Institute, E. Kardelj University, Ljubljana, YugoslaviaSearch for more papers by this author M. Drofenik, M. Drofenik J. Stefan Institute, E. Kardelj University, Ljubljana, YugoslaviaSearch for more papers by this authorA. Popović, A. Popović J. Stefan Institute, E. Kardelj University, Ljubljana, YugoslaviaSearch for more papers by this authorL. IrmanČnik, L. IrmanČnik J. Stefan Institute, E. Kardelj University, Ljubljana, YugoslaviaSearch for more papers by this authorD. Kolar, D. Kolar J. Stefan Institute, E. Kardelj University, Ljubljana, Yugoslavia Member, the American Ceramic Society.Search for more papers by this authorV. Kraševec, V. Kraševec J. Stefan Institute, E. Kardelj University, Ljubljana, YugoslaviaSearch for more papers by this author First published: December 1982 https://doi.org/10.1111/j.1151-2916.1982.tb09950.xCitations: 21 Contributing Editor-.W. J. Smothers Supported by the Research Community of Slovenia. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract The release of oxygen during the sintering of Sb2O3-doped BaTiO3 ceramics containing excess TiO2 was measured using a mass spectrometer. The amount of oxygen released is proportional to the dopant concentration in the product phase. The evolution of oxygen during sintering was attributed to dissolution of the oxidized form of doped BaTiO3 in the reacting mixture and simultaneous re-crystallization of the- reduced form. Citing Literature Volume65, Issue12December 1982Pages C‐203-C‐204 RelatedInformation