Experiments characterizing time-dependent states in the Weissenberg effect in First Brand Corporation's STP™ oil additive are described. The Weissenberg effect is the climbing of a rotating rod by a viscoelastic fluid. The results of a general survey of the states found with varying rod diameter, fluid height, and fluid temperature are presented. A detailed examination is made of the sequence of states found with a particular rod diameter and fluid depth. In this case, the Weissenberg effect is shown to exhibit characteristics of the Ruelle-Takens route to chaotic flow. In this case, the flow undergoes successive bifurcations from a time independent state to states with one frequency, two frequencies, three frequencies and then chaos, characteristic of the Ruelle-Takens route to chaos.
In investigations of conductivity of semiconducting thin films it i s generally supposed that the concentration of electrons is independent of film thickness and that the mobility of electrons does not depend on film thickness if the mean free path of the electrons i s smaller than film thickness. Experimental results, e. g. on thin films of germanium (l), lead telluride (2). tellurium (3), and cadmium sulphide (4). in which a dependence of carrier concentration and mobility on film thickness was observed for t h i c h e s s e s up to 10 p m, show that this assumption is not always satisfied for thicker films, too. In the mentioned papers the investigations were performed on several specimens of different thickness obtained from different evaporations. Such specimens a r e commonly not identical in real structure.Therefore we have measured the conductivity in dependence on growing film thickness during evaporation. The thickness was determined by optical interference fringes. The glass substrate was held at a temperature of 160 O C .
Oberflächenabdrucke von unbehandelten sowie von verschiedenen Behandlungen unterworfenen CdS‐Einkristallen wurden elektronenmikroskopisch bei 12000‐facher Vergrößerung untersucht. An Behandlungsverfahren wurden Temperungen im Hochvakuum, Bestrahlungen mit hohen Lichtintensitäten und Beschuß mit Ionen einer H2‐Gas‐entladung angewendet. Die Oberflächen der unbehandelten Kristalle zeigten in der Regel eine Belegung mit Teilchen, die eine Größe von maximal 1 μm besaßen. Eine Temperung der Kristalle im Hochvakuum führte im allgemeinen zu einer Abnahme der Teilchendichte, während bei intensiver Belichtung stets eine Zunahme der Teilchendichte beobachtet wurde. Bei Ionenbeschuß bildete sich eine polykristalline Kadmiumschicht aus. Die beobachteten Teilchen werden als Kadmiumabscheidungen gedeutet.
CdS thin films deposited onto substrates of supremax glass and fused silica were annealed at temperatures of about 700 °C in vacuum or argon atmosphere. Annealing of the samples resulted in a secondary recrystallization due to texture leading to the occurrence of monocrystalline regions with diameters up to a few millimetres. The recrystallization behaviour is similar to that observed by Gilles and Van Cakenberghe [1] and Vecht and Apling [2], however avoids strong doping connected with the technique used by these authors. The presence of oxygen or vapour of one of the components of CdS during annealing prevents the samples from secondary recrystallization, whereas covering of the CdS film with a thin silver film lowers the activation energy of recrystallization and enables therefore recrystallization at lower temperatures.
Es wurden Oberflächenabdrucke von unbehandelten sowie von verschiedenen Behandlungen unterworfenen CdS‐ und CdSe‐Aufdampfschichten elektronenmikroskopisch untersucht. Als Behandlungsverfahren wurden Temperungen im Hochvakuum, in Argon, in Stickstoff und an Luft durchgeführt. Es zeigte sich eine Zunahme der mittleren Kristallitgröße mit wachsender Kondensationstemperatur. Bei den Temperungen wurde eine Rekristallisation in inerter Atmosphäre bei Temperaturen oberhalb 500 °C, an Luft auch bereits unterhalb 500 °C, beobachtet.
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