Microstructures in advanced materials characterized by HREM and nanoscale analysis

Segregation of yttrium induces the formation of Y0.25Zr0.75O2-x and Y0.5Zr0 .5O2-y microdomains, with L1(2)- and L1(0)-like ordered structures, in ZrO2 -6mol%Y2O3 ceramics in both the sintered and annealed states. The compositi ons of precipitates such as (chi L), (chi S), (chi SS), and small precipita tes formed inside XL, in Cu-11.88Al-5.06Ni-1.63Mn-0.96Ti (wt.%) shape memor y alloys have been determined. Under electron beam irradiation, four types of dynamic behavior of the G.P. zones were observed in the Al-6.58Zn-2.33Mg -2.40Cu (wt.%) alloy. The G.P. zone and "G.P. zone-like" defect structures were also distinguished. Lattice distortion profile in the GaAs/InxGa1-xAs superlattice and two-dimensional lattice distortion around a 60 degrees dis location core in the InAs(x)P(1-)x/InP superlattice were determined. (C) El sevier Science Inc., 2000. All rights reserved.