Characterizat Ion of thin Pzt Films on Platinlm Films
Anomalous layers 20-40nm thick were found at the interfaces of lead zirconate-titanate films and Pt electrode films. Detailed study has shown evidence that absorption of PbO by Pt during sputtering resulted in a Pb deficiency in the PZT films and the formation of PbTi 3 O 7 phase. The anomaly was also partly due to island formation at the initial PZT film deposition which allowed PbO to react with Pt films. The Pb controlled PZT films 50nm thick exhibited excellent ferroelectric properties comparable to thicker ones.
Abstract Natural pozzolans have become important because of their role in concrete durability. This situation has provoked an increase in the use of pozzolanic cement in concrete construction. This paper reports results of different portland–pozzolan cements containing different natural pozzolans, and they were compared with ASTM Types I, II and V cements. The pozzolanic activity and composition of each pozzolan were evaluated. The susceptibility to sulfate attack was studied by measuring the expansion in mortar bars at different ages (according to ASTM C 1012 Method) for 78 weeks. It was found that certain cements containing pozzolans with high activity or low alumina content improve resistance to sulfate attack, although the amount of pozzolan in the cement is important.