In September we decided that KoBo extrusion / deformation experiments with high purity Zinc need to be repeated. Some of the previous samples have been analyzed after significant amount of time from original extrusion process. Some others were analyzed after much shorter time. Discrepancies in mean grain sizes observed in those two cases (much smaller grain in 'younger' sample), points to possibility of some recrystallization processes that might occur even in room temperature.
Therefore new samples of zinc after KoBo from now on are kept in liquid nitrogen in order to prevent uncontrolled recrystallization. New samples similarly to the old ones have been extruded from 40 mm diameter ingot to 1,8 mm wire in room temperature. During extrusion process, wire have been cooled with water, and immediately after extrusion samples have been cut and placed in dewar with liquid nitrogen.

The plan set in September was carrier lifetime measurements for silicon after acid texturization. The results were inconsistent with the expected (derived from the literature) because of occurring in wafers surface recombination prevented accurate measurement. For the correct measurement it is required to passivate the surface of silicon wafer what is planned for October.

In September I’ve continued the the voltammetric studies on a copper surfaces, from stable homogeneous Zn(II)-Mo(VI) citrate baths with various concetrations of sodium citrate and sodium molybdate. The voltammetric measurements were performer in a tree-electrode cell , by means of potentiostat PARSTAT 2273 or PGSTAT302N. A copper disc was the working electrode (surface area 2.83 cm2). A platinum sheet (5cm2) was used as the counter electrode. The working electrode potentials were referred to the saturated calomel electrode (SCE) and were ohmic drop, as measured by the current interrupt method, was compensated for.

Last month I took part in the ”9-th Polish-Japanese Joint Seminar on Micro and Nano Analysis” (Sieniawa, 10-13.09.2012). I had an opportunity to present a poster there entitled “Microstructure and microhardness of ball milled/hot pressed aluminium with Mg3N2 addition”, which described my first attempt to produce an AlN reinforcement in situ, in an aluminium matrix (via mechano-chemical solid state reaction).

Most of this month was spend on holidays, so there is much to write about but it does not concern science. Berore holidays i was interpreting data collected during previous month.