The effect of microstructure and chemistry on the tensile strength of Nb/sapphire interfaces with and without interlayers of Sb and Cr

摘要: Abstract Tensile strengths of interfaces between sputter-deposited Nb coatings and (0001) surfaces sapphire, with without 1–40 A thick interlayers Sb Cr are measured by a modified laser spallation experiment. The average tensile strength 1.22 GPa for the Nb/sapphire interface can be continuously increased to 2.3 controlling thickness interlayer, whereas using interlayers, controllably decreased 0.1 GPa. Although annealing Nb/Cr/sapphire samples at 600°C 24 h resulted in no change strength, heating 1200°C 10 min 2.65 GPa, due primarily formation interfacial reaction compound Cr2Nb. Similarly, Nb/Sb/sapphire 400°C marginally 0.3 locus failure upon spallation, as determined via AES XPS analysis, was sapphire adjoining metallic layer all samples. Together companion studies where atomic structure chemistry were obtained above high resolution transmission electron microscopy, strength—structure—chemistry relation is interface, Cr.