Effect Of Zr Content Research Articles

Study on the transition temperature and phase formation sequence in TiZr silicides on Si(100)

We studied the (Ti1−xZrx) silicides with various Zr atomic compositions (x=0.1, 0.3, 0.6). The effects of Zr contents on the transition (C49→C54) temperature, phase sequence, and suppression of agglomeration in TiZr alloy silicide were investigated. We codeposited the Ti and Zr films of 40 nm thickness with an e-beam evaporator in high vacuum and annealed ex situ at temperatures between 600 and 900 °C in 100 °C increments. The phase identification of TiZr silicides was carried out by x-ray diffraction (XRD) and the chemical analysis by Auger electron spectroscopy. The interface morphologies and electrical properties were investigated by the cross-sectional transmission electron microscopy and four-point probe, respectively. The increase in transition temperature was observed with increasing Zr content. TiZr alloy monosilicide was detected by XRD in the Zr composition of 60% of (TiZr) silicide at temperatures below 700 °C and finally transformed to C49 (TiZr) disilicide at temperatures above 800 °C. The interface and surface roughnesses were improved with increasing Zr content and, consistently, the resistivity of TiZr alloy silicide was decreased to μΩ due to the silicide formation and the suppression of silicide agglomeration.

Ａｌ‐Ｚｎ‐Ｍｇ‐Ｃｕ系合金の溶体化焼鈍組織の形成に及ぼす微細Ｚｒ化合物の影響

Effects of Zr contents, purities of base aluminum metals, hot and cold working on the formation of so-called unrecrystallized grains in alloys based on AA-7050 have been examined with special reference to effect of fine particles on the migration of recrystallization front.Unrecrystallized grains in solution annealed alloys formed in the regions where fine metstable Al3Zr particles under critical sizes existed. The particles precipitated during annealing of cast ingots as well as of hot worked specimens. With increasing Zr contents, the fraction of fine particle precipitated areas increased and the size of the particles decreased. The critical radii of the particles in hot and cold worked alloys were respectively 0.018μm and 0.014 μm. With Zr contents, the fraction of unrecrystailized grains increased and the size of recrystallized grains decreased also. These results lead to the following general conclusions: The fraction of unrecrystallized grains increases with the fraction of regions where fine particles under the critical size exist. The size of recrystallized grains increases with the size of fine particle free areas. Effects of purity of the base metals as well as cold working were also interpretable with this general trend.