Eiji Suito

The metal-ligand vibrations in the infrared spectra of various metal phthalocyanines

Abstract The infrared spectra of phthalocyanine and seven divalent metal derivatives have been recorded in the region 400–4000 cm−1. The metal-ligand vibration and other metal dependent bands were found and the anomalies of Cu2+ and Zn2+-phthalocyanines were interpreted on the basis of electronic configurations of outer orbitals of the metals.

Molecular image resolution in electron microscopy

In order to determine the ultimate molecular resolution attainable with a conventional electron microscope, the direct observation of hexadecachloro‐Cu‐phthalocyanine molecules was attempted. Since phthalocyanine derivatives are known to form crystalline films with columns of parallel stacks of planar molecules, the specimens were prepared by epitaxial growth on KCl cleavage face through vacuum evaporation so that the column axis was directed almost normal to the thin‐film surface holding an orientation suitable for the observation. The molecular orientation was determined by Patterson synthesis based on the laser optical transform of the electron diffraction pattern obtained from the individual crystallites placed on the microgrid mesh. The direct observation was carried out with the 100‐kV electron beam incident on the specimen along the column axis. The crosslike images arrayed in a centered rectangular net were clearly resolved, well representing the molecular shape of phthalocyanine with the configur...

Orientation Overgrowth of Condensed Polycyclic Aromatic Compounds Vacuum‐Evaporated onto Cleaved Face of Mica

When Pt‐, Cu‐, and Zn‐phthalocyanines are vacuum‐evaporated onto cleavage faces of muscovite, single‐directional orientation occurs at lower substrate temperature. At higher temperature ranges, Zn‐phthalocyanine has a double‐directional orientation while Pt‐ and Cu‐phthalocyanines show triple‐directional ones. High‐resolution electron diffraction patterns, which were well‐defined fiber diagrams, revealed that all three compounds showed conspicuous isomorphism with one another, and Zn‐ and Cu‐phthalocyanines occurred in the metastable forms of their dimorphs. General crystal structures of metastable forms are discussed on the basis of the found isomorphism with Pt‐derivative.Evaporated films were composed of lamellar crystal strips, and the fiber diagrams showed that at least two kinds of lattice orientations were assumed by all three compounds, while the longitudinal crystal axis of individual strips always ran parallel to their b axes.As to relative orientation of the evaporated films to the substrate, t...

Nucleus interaction and fine structures of colloidal gold particles

Abstract Typical gold sol particles were examined by high-resolution electron microscopy to study the nucleation and growth mechanism. The samples of colloidal gold were Faraday sol, Weimarn sol and sodium citrate sol, whose average particle diameters were estimated to be 55.2 ± 10.6 A, 131 ± 13 A and 154 ± 70 A, respectively. The shape of particles is mostly spherical excepting some of the Weimarn sol which includes pentagons with some round apices. The high resolution electron micrographs taken at a magnification of 125,000 times clearly show that the majority of the particles consist of smaller elementary crystallites with sharp boundaries which appear as parallel or radial lines defined by distinct diffraction contrasts. Moire fringes of 5–8 A spacings as well as crossed lattice images of 2.03 and 2.35 A due to (200) and (111) reflections were also observed. Systematic analyses of these contrasts indicated that the particles are formed by parallel or radial twins with definite mutual orientations. The origin of the fine structure can be attibuted to the nucleus interactions which precedes the actual growth in the early stage of sol formation. The possibility of the formation of metastable nuclei with icosahedral configuration which grow into the multiple twins and the successive transition to the natural cube-octahedral nuclei which after mutual interactions lead to the parallel twins was also discussed.

Thermal transformation of vacuum-condensed thin films of copper-phthalocyanine

Abstract Copper-phthalocyanine forms thin crystalline films of the metastable α-form with definite epitaxial orientations when vacuum- deposited onto a cleaved face of muscovite. The thermal transformation of these thin films into the stable β-form was observed by electron microscopy and electron diffraction. The transformed crystals show an epitaxial orientation with their (001) faces parallel to the substrate independent of the initial orientations. The β-form crystals grow as a long needle along its b -axis when it coincides with that of the original α-crystals, while the β-form crystals appear as relatively short flakes when both b -axes show no coincidences at all. The mechanism of thermal growth is discussed on the basis of molecular arrangement from one crystal to another as well as the influence of the lattice structure of the substrate surface.

Epitaxial growth of an organic semiconductor from the vapor phase — TCNQ on potassium chloride

Abstract Epitaxial films of 7,7′,8,8′-tetracyanoquinodimethane (TCNQ), a strong electron acceptor were formed on a KCl cleavage face by condensation from the vapor phase. Electron optical studies revealed that the films assume two different configurations depending upon the condition of the surface treatment, although they are both composed of small crystallites of ac -orientation and take multiple positioning with certain regularities characteristic of the individual types. It was deduced from specific features of the mutual orientation of the deposit and substrate crystals that epitaxial nucleation is governed primarily by the oriented adsorption of TCNQ molecules on the ionic lattice of KCl and secondarily by the sporadic matching of lattice points at the interface of both crystals.

Transformation and growth of copper-phthalocyanine crystal in organic suspension

SummaryProcesses of dimorphic transformation of copper-phthalocyanine, which took place in various organic suspension media, were traced by means of the electron microscopy and theX-ray diffractometry. It has been revealed that the preliminary growth of metastable crystals precedes the actual transition into stable crystals. The preliminary growth has been found also in the case of thin crystalline films of the metastable form vacuum-condensed onto glass plates or cleavage faces of mica, both giving rise to very large slender lamellae of the metastable form. Outward appearances as well as lattice orientations in the crystals themselves are in close resemblance to each other for those two kinds of slender lamellae of metastable and stable crystals. Two crystal habits are assumed by each of the crystal form. In parallel to the longitudinal principal zone axis, two lattice spacings ranging from 9 to 13 Å exist, while perpendicular to this axis, a lattice spacing of about 4 Å exists, again for each crystal form. The mechanism of the nucleation of stable crystals in suspension is also discussed on the basis of the similarity of outward appearance as well as lattice structure of two crystal forms.ZusammenfassungDer Prozeß der Phasenumwandlung von Kupfer-Phthalocyanin in verschiedenen organischen Suspensionen wurde elektronenmikroskopisch und röntgenographisch untersucht. Es wurde gefunden, daß vor dem Übergang in die stabile Phase die metastabilen Kristalle wachsen (Ostwald-Prinzip). Dies ist auch dann der Fall, wenn dünne Schichten der metastabilen Phase im Vakuum auf Glas oder Glimmerspaltflächen kondensiert und mit organischen Lösungsmitteln behandelt werden.In beiden Fällen entstehen sehr große, dünne Lamellen der metastabilen Form. Die äußere Form und die Gitterorientierung dieser dünnen Blättchen sind sich vor und nach der Umwandlung in die stabile Phase sehr ähnlich. In jeder der beiden Kristallformen treten parallel zur longitudinalen Hauptachse je zwei verschiedene Gitterabstände der Größe 9–13 Å auf, während senkrecht zu dieser Achse für jede der beiden Kristallformen ein prinzipieller Gitterabstand um 4 Å auftritt. Auf Grund der Ähnlichkeit der äußeren Erscheinung und der Gitterstruktur der beiden Kristallformen wird ein Keimbildungsmechanismus für die stabile Phase in Suspensionen diskutiert.

The Structure of Vacuum-deposited Films of Cadmium Telluride

Electron diffraction and electron microscopic studies were made on the structure and epitaxial growth of CdTe films deposited on a heated surface of cleaved mica. The epitaxy occurred at about 70°C. The epitaxial relation is (111)CdTe-cub//(001)Mica and [10]CdTe-cub//[100]Mica. Extra spots and streaks appeared in the transmission electron diffraction patterns. They are explained on the basis of a model that wurtzite type crystals grow on the {111} planes of a zinc-blende type crystal. In addition twinnings and stacking faults occur on these planes. The origin of stacking faults the films is also discussed.

Crystal Growth from Amorphous Phase in Thin Films

The crystal growth during crystallization of the amorphous thin films of titanium dioxide and selenium is interpreted. The nucleated crystals grow extending long in a given direction and the interfaces between crystallized and amorphous regions become indented. It is shown that the laeat generation at the crystallization and the anisotropic flow of the heat in the crystals lead to these anisotropic growths.

Construction of 300 KV Electron Microscope and Its Electronmicroscopy

The three stage voltage supply and three stage electron gun for a 300 KV electron microscope are described. Each stage of the high voltage supply is operated at 100 KV with a ripple stability of about 1×10-4 and is connected to corresponding electrode of the gun. 300 KV is applied to the top electrode directly through an insulated cable whose exterior surface is kept at 200 KV so that 300 KV is not exposed to the air. The stability when operated at about 300 KV is within 4×10-4/min. The resolving power of the electron microscope measured at 300 KV is 20 A. Transmissive powers of electron waves accelerated at 100 KV, 200 KV and 300 KV have been estimated for an aluminium single crystal from the contrast of the electron micrographs. Energy dependence of inelastic scattering in organic specimens is also shown. Electron micrographs of Mgo smoke crystals, stainless steel and polyoxy-methylene single crystals taken at 300 KV are presented.